Area of Interest 2, Geomechanics of CO 2 Reservoir Seals DE-FE0023316 Peter Eichhubl 1 , Xiaofeng Chen 1 , Owen Callahan 1 , Jon Major 1 Jon Olson 3 , Tom Dewers 2 , Pania Newell 4 1 Bureau of Economic Geology, Jackson School of Geosciences, The University of Texas at Austin 2 Sandia National Laboratories, Albuquerque, NM 3 UT Center for Petroleum & Geosystems Engineering 4 University of Utah U.S. Department of Energy National Energy Technology Laboratory Mastering the Subsurface Through Technology, Innovation and Collaboration: Carbon Storage and Oil and Natural Gas Technologies Review Meeting August 1-3, 2017 Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL8500
Transcript
Area of Interest 2Geomechanics of CO2
Reservoir SealsDE-FE0023316
Peter Eichhubl1 Xiaofeng Chen1 Owen Callahan1 Jon Major1
Jon Olson3 Tom Dewers2 Pania Newell4
1 Bureau of Economic Geology Jackson School of Geosciences The University of Texas at Austin2Sandia National Laboratories Albuquerque NM
3UT Center for Petroleum amp Geosystems Engineering4University of Utah
US Department of EnergyNational Energy Technology Laboratory
Mastering the Subsurface Through Technology Innovation and CollaborationCarbon Storage and Oil and Natural Gas Technologies Review Meeting
August 1-3 2017
Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation a wholly owned subsidiary of Lockheed Martin Corporation for the US Department of Energyrsquos National Nuclear Security Administration under contract DE-AC04-94AL8500
Problem Statementbull Sealing efficiency of CO2 reservoirs has to
exceed 99bull Design criteria are needed that establish the
long term sealing capacity of CO2 reservoirs and to model leakage risk
bull Top and fault seal risk assessment well established in oil amp gas exploration but
bull scCO2 and CO2 brine potentially interact physically amp chemically with top seal
bull Seal risk assessment criteria taking these interactions into account are needed for CO2systems 2
3
Faultcore
Faultdamage
zone
Faultdamage
zone
1 m
Normal fault in sandstone-siltstone sequence
Permeability structure of conduit-barrier fault zone
Cappa and Rutqvist 2011 Chester et al 1993
Opening-mode amp sheared opening-mode fractures control flow properties of conductive fault zonesSlip surfaces control damage zone evolution
4
Fractures in CO2 caprockCrystal Geyser field analog site
Active on 102 - 105 year time scales
5 cm
Methodologybull Experimental measurement of subcritical
fracture propagation in various shale lithologiesndash Double torsion test unconfined conditionsndash Short-rod test confined conditions (scCO2)
bull Textural and compositional characterizationndash Shale material used for fracture testingndash Post-mortem analysis of lab test specimensndash Fractures amp CO2 alteration in natural systems
bull Numerical modeling of fracture propagation in top sealsndash Fracture network modeling using JOINTSndash Upscaled modeling for top seal deformation using
Sierra Mechanics5
Mode-I fracture testing
6
Loading configuration
Log KI
Log
V
KIC
V fracture propagation velocityKI mode-I stress intensity factor K0 Stress corrosion limitKIC mode-I fracture toughnessn subcritical crack index (SCI)
Experimental setup
Testing protocolbull Three shale types
ndash Woodford Mancos Marcellusndash Also sandstones for comparisonintegration
bull Room dry CO2gas DI waterbull Varying salinity NaCl KClbull Varying pHbull Room temperature 65degC bull Some samples coated with hydrophobic
agent to limit fluidrock interaction to fracture tip 7
10Roughness variation but no plumose structureGrain boundary breakage vs transgranular breakage
300 microm
Marcellus shale
20 microm20 microm
500 microm
Mancos shale
cleavage
clay
clay
Water content
11
Frac
ture
toug
hnes
s (M
Pa m
12 )
Water enhances subcritical fracturing for clay-rich shales Strong reduction of KIC (48) and SCI (75) with increasing water content K-V curves obey power-law indicating fracturing in stress-corrosion regime (I) Load relaxation technique (lines) matches constant loading rate method (squares)
Woodford shale 23degC
Salinity
12
Woodford shale NaCl brine 23degC
Increase of fluid salinity increases KIC and SCI in clay-rich Woodford and Mancos shales
Less weakening in KCl brine than in NaCl brine Clay swelling
Uncoated
Coated
10-3
10-4
10-5
10-6
10-7
Stress Intensity Factor (MPa m12)
Frac
ture
Vel
ocity
(ms
)
0
02
04
06
0 03 06 09 12 15
K IC
(MPa
m1
2 )
Salt concentration (M)
NaClKCl
Coated
0
10
20
30
40
50
60
0 03 06 09 12 15
Subc
ritica
l Ind
exSalt concentration (M)
NaClKCl
Coated
Coated
pH
13
SCI decreases with decreasing pH for carbonate-rich Marcellus shale KIC is independent of pH SCI effect opposite to that in glass and quartzite Calcite dissolution
0
20
40
60
80
0 35 7 105 14Su
bcrit
ical I
ndex
pH
0
04
08
12
16
K IC
(MPa
m1
2 )
HCl H2O NaOH
Marcellus shale HCl solution 23degC
Temperature
14
Increase in temperature enhances subcritical fracturingbull Left-ward shift for all shalesbull Concentration effects less
2 minus 119899119899 11986011986012059012059021198841198842 1198701198701198681198681198681198682minus119899119899 minus 11987011987002minus119899119899
Constant stress loading
rArr
rArr
Assume subcritical crack growth limit 10-10 ms To meet safe storage timegt104 years σlt0004
MPa for wet σlt001 MPa for dry conditions Under σ=1 MPa failure occurs at 61 days for
wet 402 days for dry
Evans (1972) amp Nara et al (2015)
JOINTS modeling
17
bull Linear elastic Boundary element codebull Pseudo-3D accounts for elastic interaction
ndash Opening- and mixed-mode fracture propagationbull Allows simulation of fracture network development
as function of ndash Subcritical index (SCI) and KIC
ndash Elastic material propertiesndash Distribution of nucleation sites (seed fractures)
Plan and cross-section realizations
Dry CO2 DI water 1 NaCl 10 NaCl Acid
Woo
dfor
dM
arce
llus
JOINTS plan view
KIC (MParadicm)SCIνE (GPa)
100 m2
080690250
038140220
1195401528
1026401528
024140220
028110220
Qualitative differences in fracture network geometry in different chemical environmentsbull Number of fractures branching behavior curvature
1272601528
1185801528
029190220
Fracture aperture distributionCO2 003 mmDI 029 mm
Medians 1 NaCl 003 mm10 NaCl 029 mmAcid 028 mm
DI 024 mmMedians 1 NaCl 020 mm
10 NaCl 025 mmAcid 025 mm
Woo
dfor
dM
arce
llus
bull 1 NaCl Fewer but wider fractures
bull Acid More seeds activated but smaller aperture
bull Less spread in aperture range for different test environments than Woodford
JOINTS cross sections
Woodford 1 NaCl029 MParadicm 19 20 GPa
Woodford 10 NaCl024 MParadicm 14 20 GPa
2 m
10 m
Woodford DI water038 MParadicm 14 20 GPa
Woodford acid028 MParadicm 11 20 GPa
Woodford dry CO2
080 MParadicm 69 50 GPa
Summarybull Chemical environments rock mineralogy and temperature
influence shale fracture properties bull Larger wet-dry differences in clay-rich shales (Woodford and
Mancos) than in carbonate-rich shale (Marcellus)ndash ldquoWetrdquo fracture growth rate faster by one-order of magnitude
bull Increasing temperature enhances subcritical fracturingbull Carbonate-rich Marcellus carbonate dissolution
ndash SCI sensitive to acidic pHndash KIC independent of chemical environment
bull Woodford amp Mancos clay-water interactionndash KIC and SCI sensitive to water content and salinityndash Water-weakening enhances subcritical fracturing
bull Environmental effects controlled by competition between fracture growth rate and rate of rock degradation by fluid-rock interactions 21
Implications for CO2 seal integritybull Dry tests potentially applicable to dry scCO2 systems
ndash Dry-out by CO2 injection expected to strengthen caprock
bull Increasing caprock failure risk with increasing temperature
bull Clay-rich caprocksndash More pronounced dry-out effectndash Lower risk for seal failure by subcritical fracture growth
in scCO2 systemndash High salinity strengthens caprock
bull Carbonate-rich caprocksndash More prone to subcritical fracture by pH decrease
through dissolution of CO2 in brine22
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
Problem Statementbull Sealing efficiency of CO2 reservoirs has to
exceed 99bull Design criteria are needed that establish the
long term sealing capacity of CO2 reservoirs and to model leakage risk
bull Top and fault seal risk assessment well established in oil amp gas exploration but
bull scCO2 and CO2 brine potentially interact physically amp chemically with top seal
bull Seal risk assessment criteria taking these interactions into account are needed for CO2systems 2
3
Faultcore
Faultdamage
zone
Faultdamage
zone
1 m
Normal fault in sandstone-siltstone sequence
Permeability structure of conduit-barrier fault zone
Cappa and Rutqvist 2011 Chester et al 1993
Opening-mode amp sheared opening-mode fractures control flow properties of conductive fault zonesSlip surfaces control damage zone evolution
4
Fractures in CO2 caprockCrystal Geyser field analog site
Active on 102 - 105 year time scales
5 cm
Methodologybull Experimental measurement of subcritical
fracture propagation in various shale lithologiesndash Double torsion test unconfined conditionsndash Short-rod test confined conditions (scCO2)
bull Textural and compositional characterizationndash Shale material used for fracture testingndash Post-mortem analysis of lab test specimensndash Fractures amp CO2 alteration in natural systems
bull Numerical modeling of fracture propagation in top sealsndash Fracture network modeling using JOINTSndash Upscaled modeling for top seal deformation using
Sierra Mechanics5
Mode-I fracture testing
6
Loading configuration
Log KI
Log
V
KIC
V fracture propagation velocityKI mode-I stress intensity factor K0 Stress corrosion limitKIC mode-I fracture toughnessn subcritical crack index (SCI)
Experimental setup
Testing protocolbull Three shale types
ndash Woodford Mancos Marcellusndash Also sandstones for comparisonintegration
bull Room dry CO2gas DI waterbull Varying salinity NaCl KClbull Varying pHbull Room temperature 65degC bull Some samples coated with hydrophobic
agent to limit fluidrock interaction to fracture tip 7
10Roughness variation but no plumose structureGrain boundary breakage vs transgranular breakage
300 microm
Marcellus shale
20 microm20 microm
500 microm
Mancos shale
cleavage
clay
clay
Water content
11
Frac
ture
toug
hnes
s (M
Pa m
12 )
Water enhances subcritical fracturing for clay-rich shales Strong reduction of KIC (48) and SCI (75) with increasing water content K-V curves obey power-law indicating fracturing in stress-corrosion regime (I) Load relaxation technique (lines) matches constant loading rate method (squares)
Woodford shale 23degC
Salinity
12
Woodford shale NaCl brine 23degC
Increase of fluid salinity increases KIC and SCI in clay-rich Woodford and Mancos shales
Less weakening in KCl brine than in NaCl brine Clay swelling
Uncoated
Coated
10-3
10-4
10-5
10-6
10-7
Stress Intensity Factor (MPa m12)
Frac
ture
Vel
ocity
(ms
)
0
02
04
06
0 03 06 09 12 15
K IC
(MPa
m1
2 )
Salt concentration (M)
NaClKCl
Coated
0
10
20
30
40
50
60
0 03 06 09 12 15
Subc
ritica
l Ind
exSalt concentration (M)
NaClKCl
Coated
Coated
pH
13
SCI decreases with decreasing pH for carbonate-rich Marcellus shale KIC is independent of pH SCI effect opposite to that in glass and quartzite Calcite dissolution
0
20
40
60
80
0 35 7 105 14Su
bcrit
ical I
ndex
pH
0
04
08
12
16
K IC
(MPa
m1
2 )
HCl H2O NaOH
Marcellus shale HCl solution 23degC
Temperature
14
Increase in temperature enhances subcritical fracturingbull Left-ward shift for all shalesbull Concentration effects less
2 minus 119899119899 11986011986012059012059021198841198842 1198701198701198681198681198681198682minus119899119899 minus 11987011987002minus119899119899
Constant stress loading
rArr
rArr
Assume subcritical crack growth limit 10-10 ms To meet safe storage timegt104 years σlt0004
MPa for wet σlt001 MPa for dry conditions Under σ=1 MPa failure occurs at 61 days for
wet 402 days for dry
Evans (1972) amp Nara et al (2015)
JOINTS modeling
17
bull Linear elastic Boundary element codebull Pseudo-3D accounts for elastic interaction
ndash Opening- and mixed-mode fracture propagationbull Allows simulation of fracture network development
as function of ndash Subcritical index (SCI) and KIC
ndash Elastic material propertiesndash Distribution of nucleation sites (seed fractures)
Plan and cross-section realizations
Dry CO2 DI water 1 NaCl 10 NaCl Acid
Woo
dfor
dM
arce
llus
JOINTS plan view
KIC (MParadicm)SCIνE (GPa)
100 m2
080690250
038140220
1195401528
1026401528
024140220
028110220
Qualitative differences in fracture network geometry in different chemical environmentsbull Number of fractures branching behavior curvature
1272601528
1185801528
029190220
Fracture aperture distributionCO2 003 mmDI 029 mm
Medians 1 NaCl 003 mm10 NaCl 029 mmAcid 028 mm
DI 024 mmMedians 1 NaCl 020 mm
10 NaCl 025 mmAcid 025 mm
Woo
dfor
dM
arce
llus
bull 1 NaCl Fewer but wider fractures
bull Acid More seeds activated but smaller aperture
bull Less spread in aperture range for different test environments than Woodford
JOINTS cross sections
Woodford 1 NaCl029 MParadicm 19 20 GPa
Woodford 10 NaCl024 MParadicm 14 20 GPa
2 m
10 m
Woodford DI water038 MParadicm 14 20 GPa
Woodford acid028 MParadicm 11 20 GPa
Woodford dry CO2
080 MParadicm 69 50 GPa
Summarybull Chemical environments rock mineralogy and temperature
influence shale fracture properties bull Larger wet-dry differences in clay-rich shales (Woodford and
Mancos) than in carbonate-rich shale (Marcellus)ndash ldquoWetrdquo fracture growth rate faster by one-order of magnitude
bull Increasing temperature enhances subcritical fracturingbull Carbonate-rich Marcellus carbonate dissolution
ndash SCI sensitive to acidic pHndash KIC independent of chemical environment
bull Woodford amp Mancos clay-water interactionndash KIC and SCI sensitive to water content and salinityndash Water-weakening enhances subcritical fracturing
bull Environmental effects controlled by competition between fracture growth rate and rate of rock degradation by fluid-rock interactions 21
Implications for CO2 seal integritybull Dry tests potentially applicable to dry scCO2 systems
ndash Dry-out by CO2 injection expected to strengthen caprock
bull Increasing caprock failure risk with increasing temperature
bull Clay-rich caprocksndash More pronounced dry-out effectndash Lower risk for seal failure by subcritical fracture growth
in scCO2 systemndash High salinity strengthens caprock
bull Carbonate-rich caprocksndash More prone to subcritical fracture by pH decrease
through dissolution of CO2 in brine22
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
3
Faultcore
Faultdamage
zone
Faultdamage
zone
1 m
Normal fault in sandstone-siltstone sequence
Permeability structure of conduit-barrier fault zone
Cappa and Rutqvist 2011 Chester et al 1993
Opening-mode amp sheared opening-mode fractures control flow properties of conductive fault zonesSlip surfaces control damage zone evolution
4
Fractures in CO2 caprockCrystal Geyser field analog site
Active on 102 - 105 year time scales
5 cm
Methodologybull Experimental measurement of subcritical
fracture propagation in various shale lithologiesndash Double torsion test unconfined conditionsndash Short-rod test confined conditions (scCO2)
bull Textural and compositional characterizationndash Shale material used for fracture testingndash Post-mortem analysis of lab test specimensndash Fractures amp CO2 alteration in natural systems
bull Numerical modeling of fracture propagation in top sealsndash Fracture network modeling using JOINTSndash Upscaled modeling for top seal deformation using
Sierra Mechanics5
Mode-I fracture testing
6
Loading configuration
Log KI
Log
V
KIC
V fracture propagation velocityKI mode-I stress intensity factor K0 Stress corrosion limitKIC mode-I fracture toughnessn subcritical crack index (SCI)
Experimental setup
Testing protocolbull Three shale types
ndash Woodford Mancos Marcellusndash Also sandstones for comparisonintegration
bull Room dry CO2gas DI waterbull Varying salinity NaCl KClbull Varying pHbull Room temperature 65degC bull Some samples coated with hydrophobic
agent to limit fluidrock interaction to fracture tip 7
10Roughness variation but no plumose structureGrain boundary breakage vs transgranular breakage
300 microm
Marcellus shale
20 microm20 microm
500 microm
Mancos shale
cleavage
clay
clay
Water content
11
Frac
ture
toug
hnes
s (M
Pa m
12 )
Water enhances subcritical fracturing for clay-rich shales Strong reduction of KIC (48) and SCI (75) with increasing water content K-V curves obey power-law indicating fracturing in stress-corrosion regime (I) Load relaxation technique (lines) matches constant loading rate method (squares)
Woodford shale 23degC
Salinity
12
Woodford shale NaCl brine 23degC
Increase of fluid salinity increases KIC and SCI in clay-rich Woodford and Mancos shales
Less weakening in KCl brine than in NaCl brine Clay swelling
Uncoated
Coated
10-3
10-4
10-5
10-6
10-7
Stress Intensity Factor (MPa m12)
Frac
ture
Vel
ocity
(ms
)
0
02
04
06
0 03 06 09 12 15
K IC
(MPa
m1
2 )
Salt concentration (M)
NaClKCl
Coated
0
10
20
30
40
50
60
0 03 06 09 12 15
Subc
ritica
l Ind
exSalt concentration (M)
NaClKCl
Coated
Coated
pH
13
SCI decreases with decreasing pH for carbonate-rich Marcellus shale KIC is independent of pH SCI effect opposite to that in glass and quartzite Calcite dissolution
0
20
40
60
80
0 35 7 105 14Su
bcrit
ical I
ndex
pH
0
04
08
12
16
K IC
(MPa
m1
2 )
HCl H2O NaOH
Marcellus shale HCl solution 23degC
Temperature
14
Increase in temperature enhances subcritical fracturingbull Left-ward shift for all shalesbull Concentration effects less
2 minus 119899119899 11986011986012059012059021198841198842 1198701198701198681198681198681198682minus119899119899 minus 11987011987002minus119899119899
Constant stress loading
rArr
rArr
Assume subcritical crack growth limit 10-10 ms To meet safe storage timegt104 years σlt0004
MPa for wet σlt001 MPa for dry conditions Under σ=1 MPa failure occurs at 61 days for
wet 402 days for dry
Evans (1972) amp Nara et al (2015)
JOINTS modeling
17
bull Linear elastic Boundary element codebull Pseudo-3D accounts for elastic interaction
ndash Opening- and mixed-mode fracture propagationbull Allows simulation of fracture network development
as function of ndash Subcritical index (SCI) and KIC
ndash Elastic material propertiesndash Distribution of nucleation sites (seed fractures)
Plan and cross-section realizations
Dry CO2 DI water 1 NaCl 10 NaCl Acid
Woo
dfor
dM
arce
llus
JOINTS plan view
KIC (MParadicm)SCIνE (GPa)
100 m2
080690250
038140220
1195401528
1026401528
024140220
028110220
Qualitative differences in fracture network geometry in different chemical environmentsbull Number of fractures branching behavior curvature
1272601528
1185801528
029190220
Fracture aperture distributionCO2 003 mmDI 029 mm
Medians 1 NaCl 003 mm10 NaCl 029 mmAcid 028 mm
DI 024 mmMedians 1 NaCl 020 mm
10 NaCl 025 mmAcid 025 mm
Woo
dfor
dM
arce
llus
bull 1 NaCl Fewer but wider fractures
bull Acid More seeds activated but smaller aperture
bull Less spread in aperture range for different test environments than Woodford
JOINTS cross sections
Woodford 1 NaCl029 MParadicm 19 20 GPa
Woodford 10 NaCl024 MParadicm 14 20 GPa
2 m
10 m
Woodford DI water038 MParadicm 14 20 GPa
Woodford acid028 MParadicm 11 20 GPa
Woodford dry CO2
080 MParadicm 69 50 GPa
Summarybull Chemical environments rock mineralogy and temperature
influence shale fracture properties bull Larger wet-dry differences in clay-rich shales (Woodford and
Mancos) than in carbonate-rich shale (Marcellus)ndash ldquoWetrdquo fracture growth rate faster by one-order of magnitude
bull Increasing temperature enhances subcritical fracturingbull Carbonate-rich Marcellus carbonate dissolution
ndash SCI sensitive to acidic pHndash KIC independent of chemical environment
bull Woodford amp Mancos clay-water interactionndash KIC and SCI sensitive to water content and salinityndash Water-weakening enhances subcritical fracturing
bull Environmental effects controlled by competition between fracture growth rate and rate of rock degradation by fluid-rock interactions 21
Implications for CO2 seal integritybull Dry tests potentially applicable to dry scCO2 systems
ndash Dry-out by CO2 injection expected to strengthen caprock
bull Increasing caprock failure risk with increasing temperature
bull Clay-rich caprocksndash More pronounced dry-out effectndash Lower risk for seal failure by subcritical fracture growth
in scCO2 systemndash High salinity strengthens caprock
bull Carbonate-rich caprocksndash More prone to subcritical fracture by pH decrease
through dissolution of CO2 in brine22
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
4
Fractures in CO2 caprockCrystal Geyser field analog site
Active on 102 - 105 year time scales
5 cm
Methodologybull Experimental measurement of subcritical
fracture propagation in various shale lithologiesndash Double torsion test unconfined conditionsndash Short-rod test confined conditions (scCO2)
bull Textural and compositional characterizationndash Shale material used for fracture testingndash Post-mortem analysis of lab test specimensndash Fractures amp CO2 alteration in natural systems
bull Numerical modeling of fracture propagation in top sealsndash Fracture network modeling using JOINTSndash Upscaled modeling for top seal deformation using
Sierra Mechanics5
Mode-I fracture testing
6
Loading configuration
Log KI
Log
V
KIC
V fracture propagation velocityKI mode-I stress intensity factor K0 Stress corrosion limitKIC mode-I fracture toughnessn subcritical crack index (SCI)
Experimental setup
Testing protocolbull Three shale types
ndash Woodford Mancos Marcellusndash Also sandstones for comparisonintegration
bull Room dry CO2gas DI waterbull Varying salinity NaCl KClbull Varying pHbull Room temperature 65degC bull Some samples coated with hydrophobic
agent to limit fluidrock interaction to fracture tip 7
10Roughness variation but no plumose structureGrain boundary breakage vs transgranular breakage
300 microm
Marcellus shale
20 microm20 microm
500 microm
Mancos shale
cleavage
clay
clay
Water content
11
Frac
ture
toug
hnes
s (M
Pa m
12 )
Water enhances subcritical fracturing for clay-rich shales Strong reduction of KIC (48) and SCI (75) with increasing water content K-V curves obey power-law indicating fracturing in stress-corrosion regime (I) Load relaxation technique (lines) matches constant loading rate method (squares)
Woodford shale 23degC
Salinity
12
Woodford shale NaCl brine 23degC
Increase of fluid salinity increases KIC and SCI in clay-rich Woodford and Mancos shales
Less weakening in KCl brine than in NaCl brine Clay swelling
Uncoated
Coated
10-3
10-4
10-5
10-6
10-7
Stress Intensity Factor (MPa m12)
Frac
ture
Vel
ocity
(ms
)
0
02
04
06
0 03 06 09 12 15
K IC
(MPa
m1
2 )
Salt concentration (M)
NaClKCl
Coated
0
10
20
30
40
50
60
0 03 06 09 12 15
Subc
ritica
l Ind
exSalt concentration (M)
NaClKCl
Coated
Coated
pH
13
SCI decreases with decreasing pH for carbonate-rich Marcellus shale KIC is independent of pH SCI effect opposite to that in glass and quartzite Calcite dissolution
0
20
40
60
80
0 35 7 105 14Su
bcrit
ical I
ndex
pH
0
04
08
12
16
K IC
(MPa
m1
2 )
HCl H2O NaOH
Marcellus shale HCl solution 23degC
Temperature
14
Increase in temperature enhances subcritical fracturingbull Left-ward shift for all shalesbull Concentration effects less
2 minus 119899119899 11986011986012059012059021198841198842 1198701198701198681198681198681198682minus119899119899 minus 11987011987002minus119899119899
Constant stress loading
rArr
rArr
Assume subcritical crack growth limit 10-10 ms To meet safe storage timegt104 years σlt0004
MPa for wet σlt001 MPa for dry conditions Under σ=1 MPa failure occurs at 61 days for
wet 402 days for dry
Evans (1972) amp Nara et al (2015)
JOINTS modeling
17
bull Linear elastic Boundary element codebull Pseudo-3D accounts for elastic interaction
ndash Opening- and mixed-mode fracture propagationbull Allows simulation of fracture network development
as function of ndash Subcritical index (SCI) and KIC
ndash Elastic material propertiesndash Distribution of nucleation sites (seed fractures)
Plan and cross-section realizations
Dry CO2 DI water 1 NaCl 10 NaCl Acid
Woo
dfor
dM
arce
llus
JOINTS plan view
KIC (MParadicm)SCIνE (GPa)
100 m2
080690250
038140220
1195401528
1026401528
024140220
028110220
Qualitative differences in fracture network geometry in different chemical environmentsbull Number of fractures branching behavior curvature
1272601528
1185801528
029190220
Fracture aperture distributionCO2 003 mmDI 029 mm
Medians 1 NaCl 003 mm10 NaCl 029 mmAcid 028 mm
DI 024 mmMedians 1 NaCl 020 mm
10 NaCl 025 mmAcid 025 mm
Woo
dfor
dM
arce
llus
bull 1 NaCl Fewer but wider fractures
bull Acid More seeds activated but smaller aperture
bull Less spread in aperture range for different test environments than Woodford
JOINTS cross sections
Woodford 1 NaCl029 MParadicm 19 20 GPa
Woodford 10 NaCl024 MParadicm 14 20 GPa
2 m
10 m
Woodford DI water038 MParadicm 14 20 GPa
Woodford acid028 MParadicm 11 20 GPa
Woodford dry CO2
080 MParadicm 69 50 GPa
Summarybull Chemical environments rock mineralogy and temperature
influence shale fracture properties bull Larger wet-dry differences in clay-rich shales (Woodford and
Mancos) than in carbonate-rich shale (Marcellus)ndash ldquoWetrdquo fracture growth rate faster by one-order of magnitude
bull Increasing temperature enhances subcritical fracturingbull Carbonate-rich Marcellus carbonate dissolution
ndash SCI sensitive to acidic pHndash KIC independent of chemical environment
bull Woodford amp Mancos clay-water interactionndash KIC and SCI sensitive to water content and salinityndash Water-weakening enhances subcritical fracturing
bull Environmental effects controlled by competition between fracture growth rate and rate of rock degradation by fluid-rock interactions 21
Implications for CO2 seal integritybull Dry tests potentially applicable to dry scCO2 systems
ndash Dry-out by CO2 injection expected to strengthen caprock
bull Increasing caprock failure risk with increasing temperature
bull Clay-rich caprocksndash More pronounced dry-out effectndash Lower risk for seal failure by subcritical fracture growth
in scCO2 systemndash High salinity strengthens caprock
bull Carbonate-rich caprocksndash More prone to subcritical fracture by pH decrease
through dissolution of CO2 in brine22
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
Methodologybull Experimental measurement of subcritical
fracture propagation in various shale lithologiesndash Double torsion test unconfined conditionsndash Short-rod test confined conditions (scCO2)
bull Textural and compositional characterizationndash Shale material used for fracture testingndash Post-mortem analysis of lab test specimensndash Fractures amp CO2 alteration in natural systems
bull Numerical modeling of fracture propagation in top sealsndash Fracture network modeling using JOINTSndash Upscaled modeling for top seal deformation using
Sierra Mechanics5
Mode-I fracture testing
6
Loading configuration
Log KI
Log
V
KIC
V fracture propagation velocityKI mode-I stress intensity factor K0 Stress corrosion limitKIC mode-I fracture toughnessn subcritical crack index (SCI)
Experimental setup
Testing protocolbull Three shale types
ndash Woodford Mancos Marcellusndash Also sandstones for comparisonintegration
bull Room dry CO2gas DI waterbull Varying salinity NaCl KClbull Varying pHbull Room temperature 65degC bull Some samples coated with hydrophobic
agent to limit fluidrock interaction to fracture tip 7
10Roughness variation but no plumose structureGrain boundary breakage vs transgranular breakage
300 microm
Marcellus shale
20 microm20 microm
500 microm
Mancos shale
cleavage
clay
clay
Water content
11
Frac
ture
toug
hnes
s (M
Pa m
12 )
Water enhances subcritical fracturing for clay-rich shales Strong reduction of KIC (48) and SCI (75) with increasing water content K-V curves obey power-law indicating fracturing in stress-corrosion regime (I) Load relaxation technique (lines) matches constant loading rate method (squares)
Woodford shale 23degC
Salinity
12
Woodford shale NaCl brine 23degC
Increase of fluid salinity increases KIC and SCI in clay-rich Woodford and Mancos shales
Less weakening in KCl brine than in NaCl brine Clay swelling
Uncoated
Coated
10-3
10-4
10-5
10-6
10-7
Stress Intensity Factor (MPa m12)
Frac
ture
Vel
ocity
(ms
)
0
02
04
06
0 03 06 09 12 15
K IC
(MPa
m1
2 )
Salt concentration (M)
NaClKCl
Coated
0
10
20
30
40
50
60
0 03 06 09 12 15
Subc
ritica
l Ind
exSalt concentration (M)
NaClKCl
Coated
Coated
pH
13
SCI decreases with decreasing pH for carbonate-rich Marcellus shale KIC is independent of pH SCI effect opposite to that in glass and quartzite Calcite dissolution
0
20
40
60
80
0 35 7 105 14Su
bcrit
ical I
ndex
pH
0
04
08
12
16
K IC
(MPa
m1
2 )
HCl H2O NaOH
Marcellus shale HCl solution 23degC
Temperature
14
Increase in temperature enhances subcritical fracturingbull Left-ward shift for all shalesbull Concentration effects less
2 minus 119899119899 11986011986012059012059021198841198842 1198701198701198681198681198681198682minus119899119899 minus 11987011987002minus119899119899
Constant stress loading
rArr
rArr
Assume subcritical crack growth limit 10-10 ms To meet safe storage timegt104 years σlt0004
MPa for wet σlt001 MPa for dry conditions Under σ=1 MPa failure occurs at 61 days for
wet 402 days for dry
Evans (1972) amp Nara et al (2015)
JOINTS modeling
17
bull Linear elastic Boundary element codebull Pseudo-3D accounts for elastic interaction
ndash Opening- and mixed-mode fracture propagationbull Allows simulation of fracture network development
as function of ndash Subcritical index (SCI) and KIC
ndash Elastic material propertiesndash Distribution of nucleation sites (seed fractures)
Plan and cross-section realizations
Dry CO2 DI water 1 NaCl 10 NaCl Acid
Woo
dfor
dM
arce
llus
JOINTS plan view
KIC (MParadicm)SCIνE (GPa)
100 m2
080690250
038140220
1195401528
1026401528
024140220
028110220
Qualitative differences in fracture network geometry in different chemical environmentsbull Number of fractures branching behavior curvature
1272601528
1185801528
029190220
Fracture aperture distributionCO2 003 mmDI 029 mm
Medians 1 NaCl 003 mm10 NaCl 029 mmAcid 028 mm
DI 024 mmMedians 1 NaCl 020 mm
10 NaCl 025 mmAcid 025 mm
Woo
dfor
dM
arce
llus
bull 1 NaCl Fewer but wider fractures
bull Acid More seeds activated but smaller aperture
bull Less spread in aperture range for different test environments than Woodford
JOINTS cross sections
Woodford 1 NaCl029 MParadicm 19 20 GPa
Woodford 10 NaCl024 MParadicm 14 20 GPa
2 m
10 m
Woodford DI water038 MParadicm 14 20 GPa
Woodford acid028 MParadicm 11 20 GPa
Woodford dry CO2
080 MParadicm 69 50 GPa
Summarybull Chemical environments rock mineralogy and temperature
influence shale fracture properties bull Larger wet-dry differences in clay-rich shales (Woodford and
Mancos) than in carbonate-rich shale (Marcellus)ndash ldquoWetrdquo fracture growth rate faster by one-order of magnitude
bull Increasing temperature enhances subcritical fracturingbull Carbonate-rich Marcellus carbonate dissolution
ndash SCI sensitive to acidic pHndash KIC independent of chemical environment
bull Woodford amp Mancos clay-water interactionndash KIC and SCI sensitive to water content and salinityndash Water-weakening enhances subcritical fracturing
bull Environmental effects controlled by competition between fracture growth rate and rate of rock degradation by fluid-rock interactions 21
Implications for CO2 seal integritybull Dry tests potentially applicable to dry scCO2 systems
ndash Dry-out by CO2 injection expected to strengthen caprock
bull Increasing caprock failure risk with increasing temperature
bull Clay-rich caprocksndash More pronounced dry-out effectndash Lower risk for seal failure by subcritical fracture growth
in scCO2 systemndash High salinity strengthens caprock
bull Carbonate-rich caprocksndash More prone to subcritical fracture by pH decrease
through dissolution of CO2 in brine22
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
Mode-I fracture testing
6
Loading configuration
Log KI
Log
V
KIC
V fracture propagation velocityKI mode-I stress intensity factor K0 Stress corrosion limitKIC mode-I fracture toughnessn subcritical crack index (SCI)
Experimental setup
Testing protocolbull Three shale types
ndash Woodford Mancos Marcellusndash Also sandstones for comparisonintegration
bull Room dry CO2gas DI waterbull Varying salinity NaCl KClbull Varying pHbull Room temperature 65degC bull Some samples coated with hydrophobic
agent to limit fluidrock interaction to fracture tip 7
10Roughness variation but no plumose structureGrain boundary breakage vs transgranular breakage
300 microm
Marcellus shale
20 microm20 microm
500 microm
Mancos shale
cleavage
clay
clay
Water content
11
Frac
ture
toug
hnes
s (M
Pa m
12 )
Water enhances subcritical fracturing for clay-rich shales Strong reduction of KIC (48) and SCI (75) with increasing water content K-V curves obey power-law indicating fracturing in stress-corrosion regime (I) Load relaxation technique (lines) matches constant loading rate method (squares)
Woodford shale 23degC
Salinity
12
Woodford shale NaCl brine 23degC
Increase of fluid salinity increases KIC and SCI in clay-rich Woodford and Mancos shales
Less weakening in KCl brine than in NaCl brine Clay swelling
Uncoated
Coated
10-3
10-4
10-5
10-6
10-7
Stress Intensity Factor (MPa m12)
Frac
ture
Vel
ocity
(ms
)
0
02
04
06
0 03 06 09 12 15
K IC
(MPa
m1
2 )
Salt concentration (M)
NaClKCl
Coated
0
10
20
30
40
50
60
0 03 06 09 12 15
Subc
ritica
l Ind
exSalt concentration (M)
NaClKCl
Coated
Coated
pH
13
SCI decreases with decreasing pH for carbonate-rich Marcellus shale KIC is independent of pH SCI effect opposite to that in glass and quartzite Calcite dissolution
0
20
40
60
80
0 35 7 105 14Su
bcrit
ical I
ndex
pH
0
04
08
12
16
K IC
(MPa
m1
2 )
HCl H2O NaOH
Marcellus shale HCl solution 23degC
Temperature
14
Increase in temperature enhances subcritical fracturingbull Left-ward shift for all shalesbull Concentration effects less
2 minus 119899119899 11986011986012059012059021198841198842 1198701198701198681198681198681198682minus119899119899 minus 11987011987002minus119899119899
Constant stress loading
rArr
rArr
Assume subcritical crack growth limit 10-10 ms To meet safe storage timegt104 years σlt0004
MPa for wet σlt001 MPa for dry conditions Under σ=1 MPa failure occurs at 61 days for
wet 402 days for dry
Evans (1972) amp Nara et al (2015)
JOINTS modeling
17
bull Linear elastic Boundary element codebull Pseudo-3D accounts for elastic interaction
ndash Opening- and mixed-mode fracture propagationbull Allows simulation of fracture network development
as function of ndash Subcritical index (SCI) and KIC
ndash Elastic material propertiesndash Distribution of nucleation sites (seed fractures)
Plan and cross-section realizations
Dry CO2 DI water 1 NaCl 10 NaCl Acid
Woo
dfor
dM
arce
llus
JOINTS plan view
KIC (MParadicm)SCIνE (GPa)
100 m2
080690250
038140220
1195401528
1026401528
024140220
028110220
Qualitative differences in fracture network geometry in different chemical environmentsbull Number of fractures branching behavior curvature
1272601528
1185801528
029190220
Fracture aperture distributionCO2 003 mmDI 029 mm
Medians 1 NaCl 003 mm10 NaCl 029 mmAcid 028 mm
DI 024 mmMedians 1 NaCl 020 mm
10 NaCl 025 mmAcid 025 mm
Woo
dfor
dM
arce
llus
bull 1 NaCl Fewer but wider fractures
bull Acid More seeds activated but smaller aperture
bull Less spread in aperture range for different test environments than Woodford
JOINTS cross sections
Woodford 1 NaCl029 MParadicm 19 20 GPa
Woodford 10 NaCl024 MParadicm 14 20 GPa
2 m
10 m
Woodford DI water038 MParadicm 14 20 GPa
Woodford acid028 MParadicm 11 20 GPa
Woodford dry CO2
080 MParadicm 69 50 GPa
Summarybull Chemical environments rock mineralogy and temperature
influence shale fracture properties bull Larger wet-dry differences in clay-rich shales (Woodford and
Mancos) than in carbonate-rich shale (Marcellus)ndash ldquoWetrdquo fracture growth rate faster by one-order of magnitude
bull Increasing temperature enhances subcritical fracturingbull Carbonate-rich Marcellus carbonate dissolution
ndash SCI sensitive to acidic pHndash KIC independent of chemical environment
bull Woodford amp Mancos clay-water interactionndash KIC and SCI sensitive to water content and salinityndash Water-weakening enhances subcritical fracturing
bull Environmental effects controlled by competition between fracture growth rate and rate of rock degradation by fluid-rock interactions 21
Implications for CO2 seal integritybull Dry tests potentially applicable to dry scCO2 systems
ndash Dry-out by CO2 injection expected to strengthen caprock
bull Increasing caprock failure risk with increasing temperature
bull Clay-rich caprocksndash More pronounced dry-out effectndash Lower risk for seal failure by subcritical fracture growth
in scCO2 systemndash High salinity strengthens caprock
bull Carbonate-rich caprocksndash More prone to subcritical fracture by pH decrease
through dissolution of CO2 in brine22
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
Testing protocolbull Three shale types
ndash Woodford Mancos Marcellusndash Also sandstones for comparisonintegration
bull Room dry CO2gas DI waterbull Varying salinity NaCl KClbull Varying pHbull Room temperature 65degC bull Some samples coated with hydrophobic
agent to limit fluidrock interaction to fracture tip 7
10Roughness variation but no plumose structureGrain boundary breakage vs transgranular breakage
300 microm
Marcellus shale
20 microm20 microm
500 microm
Mancos shale
cleavage
clay
clay
Water content
11
Frac
ture
toug
hnes
s (M
Pa m
12 )
Water enhances subcritical fracturing for clay-rich shales Strong reduction of KIC (48) and SCI (75) with increasing water content K-V curves obey power-law indicating fracturing in stress-corrosion regime (I) Load relaxation technique (lines) matches constant loading rate method (squares)
Woodford shale 23degC
Salinity
12
Woodford shale NaCl brine 23degC
Increase of fluid salinity increases KIC and SCI in clay-rich Woodford and Mancos shales
Less weakening in KCl brine than in NaCl brine Clay swelling
Uncoated
Coated
10-3
10-4
10-5
10-6
10-7
Stress Intensity Factor (MPa m12)
Frac
ture
Vel
ocity
(ms
)
0
02
04
06
0 03 06 09 12 15
K IC
(MPa
m1
2 )
Salt concentration (M)
NaClKCl
Coated
0
10
20
30
40
50
60
0 03 06 09 12 15
Subc
ritica
l Ind
exSalt concentration (M)
NaClKCl
Coated
Coated
pH
13
SCI decreases with decreasing pH for carbonate-rich Marcellus shale KIC is independent of pH SCI effect opposite to that in glass and quartzite Calcite dissolution
0
20
40
60
80
0 35 7 105 14Su
bcrit
ical I
ndex
pH
0
04
08
12
16
K IC
(MPa
m1
2 )
HCl H2O NaOH
Marcellus shale HCl solution 23degC
Temperature
14
Increase in temperature enhances subcritical fracturingbull Left-ward shift for all shalesbull Concentration effects less
2 minus 119899119899 11986011986012059012059021198841198842 1198701198701198681198681198681198682minus119899119899 minus 11987011987002minus119899119899
Constant stress loading
rArr
rArr
Assume subcritical crack growth limit 10-10 ms To meet safe storage timegt104 years σlt0004
MPa for wet σlt001 MPa for dry conditions Under σ=1 MPa failure occurs at 61 days for
wet 402 days for dry
Evans (1972) amp Nara et al (2015)
JOINTS modeling
17
bull Linear elastic Boundary element codebull Pseudo-3D accounts for elastic interaction
ndash Opening- and mixed-mode fracture propagationbull Allows simulation of fracture network development
as function of ndash Subcritical index (SCI) and KIC
ndash Elastic material propertiesndash Distribution of nucleation sites (seed fractures)
Plan and cross-section realizations
Dry CO2 DI water 1 NaCl 10 NaCl Acid
Woo
dfor
dM
arce
llus
JOINTS plan view
KIC (MParadicm)SCIνE (GPa)
100 m2
080690250
038140220
1195401528
1026401528
024140220
028110220
Qualitative differences in fracture network geometry in different chemical environmentsbull Number of fractures branching behavior curvature
1272601528
1185801528
029190220
Fracture aperture distributionCO2 003 mmDI 029 mm
Medians 1 NaCl 003 mm10 NaCl 029 mmAcid 028 mm
DI 024 mmMedians 1 NaCl 020 mm
10 NaCl 025 mmAcid 025 mm
Woo
dfor
dM
arce
llus
bull 1 NaCl Fewer but wider fractures
bull Acid More seeds activated but smaller aperture
bull Less spread in aperture range for different test environments than Woodford
JOINTS cross sections
Woodford 1 NaCl029 MParadicm 19 20 GPa
Woodford 10 NaCl024 MParadicm 14 20 GPa
2 m
10 m
Woodford DI water038 MParadicm 14 20 GPa
Woodford acid028 MParadicm 11 20 GPa
Woodford dry CO2
080 MParadicm 69 50 GPa
Summarybull Chemical environments rock mineralogy and temperature
influence shale fracture properties bull Larger wet-dry differences in clay-rich shales (Woodford and
Mancos) than in carbonate-rich shale (Marcellus)ndash ldquoWetrdquo fracture growth rate faster by one-order of magnitude
bull Increasing temperature enhances subcritical fracturingbull Carbonate-rich Marcellus carbonate dissolution
ndash SCI sensitive to acidic pHndash KIC independent of chemical environment
bull Woodford amp Mancos clay-water interactionndash KIC and SCI sensitive to water content and salinityndash Water-weakening enhances subcritical fracturing
bull Environmental effects controlled by competition between fracture growth rate and rate of rock degradation by fluid-rock interactions 21
Implications for CO2 seal integritybull Dry tests potentially applicable to dry scCO2 systems
ndash Dry-out by CO2 injection expected to strengthen caprock
bull Increasing caprock failure risk with increasing temperature
bull Clay-rich caprocksndash More pronounced dry-out effectndash Lower risk for seal failure by subcritical fracture growth
in scCO2 systemndash High salinity strengthens caprock
bull Carbonate-rich caprocksndash More prone to subcritical fracture by pH decrease
through dissolution of CO2 in brine22
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
10Roughness variation but no plumose structureGrain boundary breakage vs transgranular breakage
300 microm
Marcellus shale
20 microm20 microm
500 microm
Mancos shale
cleavage
clay
clay
Water content
11
Frac
ture
toug
hnes
s (M
Pa m
12 )
Water enhances subcritical fracturing for clay-rich shales Strong reduction of KIC (48) and SCI (75) with increasing water content K-V curves obey power-law indicating fracturing in stress-corrosion regime (I) Load relaxation technique (lines) matches constant loading rate method (squares)
Woodford shale 23degC
Salinity
12
Woodford shale NaCl brine 23degC
Increase of fluid salinity increases KIC and SCI in clay-rich Woodford and Mancos shales
Less weakening in KCl brine than in NaCl brine Clay swelling
Uncoated
Coated
10-3
10-4
10-5
10-6
10-7
Stress Intensity Factor (MPa m12)
Frac
ture
Vel
ocity
(ms
)
0
02
04
06
0 03 06 09 12 15
K IC
(MPa
m1
2 )
Salt concentration (M)
NaClKCl
Coated
0
10
20
30
40
50
60
0 03 06 09 12 15
Subc
ritica
l Ind
exSalt concentration (M)
NaClKCl
Coated
Coated
pH
13
SCI decreases with decreasing pH for carbonate-rich Marcellus shale KIC is independent of pH SCI effect opposite to that in glass and quartzite Calcite dissolution
0
20
40
60
80
0 35 7 105 14Su
bcrit
ical I
ndex
pH
0
04
08
12
16
K IC
(MPa
m1
2 )
HCl H2O NaOH
Marcellus shale HCl solution 23degC
Temperature
14
Increase in temperature enhances subcritical fracturingbull Left-ward shift for all shalesbull Concentration effects less
2 minus 119899119899 11986011986012059012059021198841198842 1198701198701198681198681198681198682minus119899119899 minus 11987011987002minus119899119899
Constant stress loading
rArr
rArr
Assume subcritical crack growth limit 10-10 ms To meet safe storage timegt104 years σlt0004
MPa for wet σlt001 MPa for dry conditions Under σ=1 MPa failure occurs at 61 days for
wet 402 days for dry
Evans (1972) amp Nara et al (2015)
JOINTS modeling
17
bull Linear elastic Boundary element codebull Pseudo-3D accounts for elastic interaction
ndash Opening- and mixed-mode fracture propagationbull Allows simulation of fracture network development
as function of ndash Subcritical index (SCI) and KIC
ndash Elastic material propertiesndash Distribution of nucleation sites (seed fractures)
Plan and cross-section realizations
Dry CO2 DI water 1 NaCl 10 NaCl Acid
Woo
dfor
dM
arce
llus
JOINTS plan view
KIC (MParadicm)SCIνE (GPa)
100 m2
080690250
038140220
1195401528
1026401528
024140220
028110220
Qualitative differences in fracture network geometry in different chemical environmentsbull Number of fractures branching behavior curvature
1272601528
1185801528
029190220
Fracture aperture distributionCO2 003 mmDI 029 mm
Medians 1 NaCl 003 mm10 NaCl 029 mmAcid 028 mm
DI 024 mmMedians 1 NaCl 020 mm
10 NaCl 025 mmAcid 025 mm
Woo
dfor
dM
arce
llus
bull 1 NaCl Fewer but wider fractures
bull Acid More seeds activated but smaller aperture
bull Less spread in aperture range for different test environments than Woodford
JOINTS cross sections
Woodford 1 NaCl029 MParadicm 19 20 GPa
Woodford 10 NaCl024 MParadicm 14 20 GPa
2 m
10 m
Woodford DI water038 MParadicm 14 20 GPa
Woodford acid028 MParadicm 11 20 GPa
Woodford dry CO2
080 MParadicm 69 50 GPa
Summarybull Chemical environments rock mineralogy and temperature
influence shale fracture properties bull Larger wet-dry differences in clay-rich shales (Woodford and
Mancos) than in carbonate-rich shale (Marcellus)ndash ldquoWetrdquo fracture growth rate faster by one-order of magnitude
bull Increasing temperature enhances subcritical fracturingbull Carbonate-rich Marcellus carbonate dissolution
ndash SCI sensitive to acidic pHndash KIC independent of chemical environment
bull Woodford amp Mancos clay-water interactionndash KIC and SCI sensitive to water content and salinityndash Water-weakening enhances subcritical fracturing
bull Environmental effects controlled by competition between fracture growth rate and rate of rock degradation by fluid-rock interactions 21
Implications for CO2 seal integritybull Dry tests potentially applicable to dry scCO2 systems
ndash Dry-out by CO2 injection expected to strengthen caprock
bull Increasing caprock failure risk with increasing temperature
bull Clay-rich caprocksndash More pronounced dry-out effectndash Lower risk for seal failure by subcritical fracture growth
in scCO2 systemndash High salinity strengthens caprock
bull Carbonate-rich caprocksndash More prone to subcritical fracture by pH decrease
through dissolution of CO2 in brine22
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
10Roughness variation but no plumose structureGrain boundary breakage vs transgranular breakage
300 microm
Marcellus shale
20 microm20 microm
500 microm
Mancos shale
cleavage
clay
clay
Water content
11
Frac
ture
toug
hnes
s (M
Pa m
12 )
Water enhances subcritical fracturing for clay-rich shales Strong reduction of KIC (48) and SCI (75) with increasing water content K-V curves obey power-law indicating fracturing in stress-corrosion regime (I) Load relaxation technique (lines) matches constant loading rate method (squares)
Woodford shale 23degC
Salinity
12
Woodford shale NaCl brine 23degC
Increase of fluid salinity increases KIC and SCI in clay-rich Woodford and Mancos shales
Less weakening in KCl brine than in NaCl brine Clay swelling
Uncoated
Coated
10-3
10-4
10-5
10-6
10-7
Stress Intensity Factor (MPa m12)
Frac
ture
Vel
ocity
(ms
)
0
02
04
06
0 03 06 09 12 15
K IC
(MPa
m1
2 )
Salt concentration (M)
NaClKCl
Coated
0
10
20
30
40
50
60
0 03 06 09 12 15
Subc
ritica
l Ind
exSalt concentration (M)
NaClKCl
Coated
Coated
pH
13
SCI decreases with decreasing pH for carbonate-rich Marcellus shale KIC is independent of pH SCI effect opposite to that in glass and quartzite Calcite dissolution
0
20
40
60
80
0 35 7 105 14Su
bcrit
ical I
ndex
pH
0
04
08
12
16
K IC
(MPa
m1
2 )
HCl H2O NaOH
Marcellus shale HCl solution 23degC
Temperature
14
Increase in temperature enhances subcritical fracturingbull Left-ward shift for all shalesbull Concentration effects less
2 minus 119899119899 11986011986012059012059021198841198842 1198701198701198681198681198681198682minus119899119899 minus 11987011987002minus119899119899
Constant stress loading
rArr
rArr
Assume subcritical crack growth limit 10-10 ms To meet safe storage timegt104 years σlt0004
MPa for wet σlt001 MPa for dry conditions Under σ=1 MPa failure occurs at 61 days for
wet 402 days for dry
Evans (1972) amp Nara et al (2015)
JOINTS modeling
17
bull Linear elastic Boundary element codebull Pseudo-3D accounts for elastic interaction
ndash Opening- and mixed-mode fracture propagationbull Allows simulation of fracture network development
as function of ndash Subcritical index (SCI) and KIC
ndash Elastic material propertiesndash Distribution of nucleation sites (seed fractures)
Plan and cross-section realizations
Dry CO2 DI water 1 NaCl 10 NaCl Acid
Woo
dfor
dM
arce
llus
JOINTS plan view
KIC (MParadicm)SCIνE (GPa)
100 m2
080690250
038140220
1195401528
1026401528
024140220
028110220
Qualitative differences in fracture network geometry in different chemical environmentsbull Number of fractures branching behavior curvature
1272601528
1185801528
029190220
Fracture aperture distributionCO2 003 mmDI 029 mm
Medians 1 NaCl 003 mm10 NaCl 029 mmAcid 028 mm
DI 024 mmMedians 1 NaCl 020 mm
10 NaCl 025 mmAcid 025 mm
Woo
dfor
dM
arce
llus
bull 1 NaCl Fewer but wider fractures
bull Acid More seeds activated but smaller aperture
bull Less spread in aperture range for different test environments than Woodford
JOINTS cross sections
Woodford 1 NaCl029 MParadicm 19 20 GPa
Woodford 10 NaCl024 MParadicm 14 20 GPa
2 m
10 m
Woodford DI water038 MParadicm 14 20 GPa
Woodford acid028 MParadicm 11 20 GPa
Woodford dry CO2
080 MParadicm 69 50 GPa
Summarybull Chemical environments rock mineralogy and temperature
influence shale fracture properties bull Larger wet-dry differences in clay-rich shales (Woodford and
Mancos) than in carbonate-rich shale (Marcellus)ndash ldquoWetrdquo fracture growth rate faster by one-order of magnitude
bull Increasing temperature enhances subcritical fracturingbull Carbonate-rich Marcellus carbonate dissolution
ndash SCI sensitive to acidic pHndash KIC independent of chemical environment
bull Woodford amp Mancos clay-water interactionndash KIC and SCI sensitive to water content and salinityndash Water-weakening enhances subcritical fracturing
bull Environmental effects controlled by competition between fracture growth rate and rate of rock degradation by fluid-rock interactions 21
Implications for CO2 seal integritybull Dry tests potentially applicable to dry scCO2 systems
ndash Dry-out by CO2 injection expected to strengthen caprock
bull Increasing caprock failure risk with increasing temperature
bull Clay-rich caprocksndash More pronounced dry-out effectndash Lower risk for seal failure by subcritical fracture growth
in scCO2 systemndash High salinity strengthens caprock
bull Carbonate-rich caprocksndash More prone to subcritical fracture by pH decrease
through dissolution of CO2 in brine22
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
Fracture surface imaging
10Roughness variation but no plumose structureGrain boundary breakage vs transgranular breakage
300 microm
Marcellus shale
20 microm20 microm
500 microm
Mancos shale
cleavage
clay
clay
Water content
11
Frac
ture
toug
hnes
s (M
Pa m
12 )
Water enhances subcritical fracturing for clay-rich shales Strong reduction of KIC (48) and SCI (75) with increasing water content K-V curves obey power-law indicating fracturing in stress-corrosion regime (I) Load relaxation technique (lines) matches constant loading rate method (squares)
Woodford shale 23degC
Salinity
12
Woodford shale NaCl brine 23degC
Increase of fluid salinity increases KIC and SCI in clay-rich Woodford and Mancos shales
Less weakening in KCl brine than in NaCl brine Clay swelling
Uncoated
Coated
10-3
10-4
10-5
10-6
10-7
Stress Intensity Factor (MPa m12)
Frac
ture
Vel
ocity
(ms
)
0
02
04
06
0 03 06 09 12 15
K IC
(MPa
m1
2 )
Salt concentration (M)
NaClKCl
Coated
0
10
20
30
40
50
60
0 03 06 09 12 15
Subc
ritica
l Ind
exSalt concentration (M)
NaClKCl
Coated
Coated
pH
13
SCI decreases with decreasing pH for carbonate-rich Marcellus shale KIC is independent of pH SCI effect opposite to that in glass and quartzite Calcite dissolution
0
20
40
60
80
0 35 7 105 14Su
bcrit
ical I
ndex
pH
0
04
08
12
16
K IC
(MPa
m1
2 )
HCl H2O NaOH
Marcellus shale HCl solution 23degC
Temperature
14
Increase in temperature enhances subcritical fracturingbull Left-ward shift for all shalesbull Concentration effects less
2 minus 119899119899 11986011986012059012059021198841198842 1198701198701198681198681198681198682minus119899119899 minus 11987011987002minus119899119899
Constant stress loading
rArr
rArr
Assume subcritical crack growth limit 10-10 ms To meet safe storage timegt104 years σlt0004
MPa for wet σlt001 MPa for dry conditions Under σ=1 MPa failure occurs at 61 days for
wet 402 days for dry
Evans (1972) amp Nara et al (2015)
JOINTS modeling
17
bull Linear elastic Boundary element codebull Pseudo-3D accounts for elastic interaction
ndash Opening- and mixed-mode fracture propagationbull Allows simulation of fracture network development
as function of ndash Subcritical index (SCI) and KIC
ndash Elastic material propertiesndash Distribution of nucleation sites (seed fractures)
Plan and cross-section realizations
Dry CO2 DI water 1 NaCl 10 NaCl Acid
Woo
dfor
dM
arce
llus
JOINTS plan view
KIC (MParadicm)SCIνE (GPa)
100 m2
080690250
038140220
1195401528
1026401528
024140220
028110220
Qualitative differences in fracture network geometry in different chemical environmentsbull Number of fractures branching behavior curvature
1272601528
1185801528
029190220
Fracture aperture distributionCO2 003 mmDI 029 mm
Medians 1 NaCl 003 mm10 NaCl 029 mmAcid 028 mm
DI 024 mmMedians 1 NaCl 020 mm
10 NaCl 025 mmAcid 025 mm
Woo
dfor
dM
arce
llus
bull 1 NaCl Fewer but wider fractures
bull Acid More seeds activated but smaller aperture
bull Less spread in aperture range for different test environments than Woodford
JOINTS cross sections
Woodford 1 NaCl029 MParadicm 19 20 GPa
Woodford 10 NaCl024 MParadicm 14 20 GPa
2 m
10 m
Woodford DI water038 MParadicm 14 20 GPa
Woodford acid028 MParadicm 11 20 GPa
Woodford dry CO2
080 MParadicm 69 50 GPa
Summarybull Chemical environments rock mineralogy and temperature
influence shale fracture properties bull Larger wet-dry differences in clay-rich shales (Woodford and
Mancos) than in carbonate-rich shale (Marcellus)ndash ldquoWetrdquo fracture growth rate faster by one-order of magnitude
bull Increasing temperature enhances subcritical fracturingbull Carbonate-rich Marcellus carbonate dissolution
ndash SCI sensitive to acidic pHndash KIC independent of chemical environment
bull Woodford amp Mancos clay-water interactionndash KIC and SCI sensitive to water content and salinityndash Water-weakening enhances subcritical fracturing
bull Environmental effects controlled by competition between fracture growth rate and rate of rock degradation by fluid-rock interactions 21
Implications for CO2 seal integritybull Dry tests potentially applicable to dry scCO2 systems
ndash Dry-out by CO2 injection expected to strengthen caprock
bull Increasing caprock failure risk with increasing temperature
bull Clay-rich caprocksndash More pronounced dry-out effectndash Lower risk for seal failure by subcritical fracture growth
in scCO2 systemndash High salinity strengthens caprock
bull Carbonate-rich caprocksndash More prone to subcritical fracture by pH decrease
through dissolution of CO2 in brine22
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
Water content
11
Frac
ture
toug
hnes
s (M
Pa m
12 )
Water enhances subcritical fracturing for clay-rich shales Strong reduction of KIC (48) and SCI (75) with increasing water content K-V curves obey power-law indicating fracturing in stress-corrosion regime (I) Load relaxation technique (lines) matches constant loading rate method (squares)
Woodford shale 23degC
Salinity
12
Woodford shale NaCl brine 23degC
Increase of fluid salinity increases KIC and SCI in clay-rich Woodford and Mancos shales
Less weakening in KCl brine than in NaCl brine Clay swelling
Uncoated
Coated
10-3
10-4
10-5
10-6
10-7
Stress Intensity Factor (MPa m12)
Frac
ture
Vel
ocity
(ms
)
0
02
04
06
0 03 06 09 12 15
K IC
(MPa
m1
2 )
Salt concentration (M)
NaClKCl
Coated
0
10
20
30
40
50
60
0 03 06 09 12 15
Subc
ritica
l Ind
exSalt concentration (M)
NaClKCl
Coated
Coated
pH
13
SCI decreases with decreasing pH for carbonate-rich Marcellus shale KIC is independent of pH SCI effect opposite to that in glass and quartzite Calcite dissolution
0
20
40
60
80
0 35 7 105 14Su
bcrit
ical I
ndex
pH
0
04
08
12
16
K IC
(MPa
m1
2 )
HCl H2O NaOH
Marcellus shale HCl solution 23degC
Temperature
14
Increase in temperature enhances subcritical fracturingbull Left-ward shift for all shalesbull Concentration effects less
2 minus 119899119899 11986011986012059012059021198841198842 1198701198701198681198681198681198682minus119899119899 minus 11987011987002minus119899119899
Constant stress loading
rArr
rArr
Assume subcritical crack growth limit 10-10 ms To meet safe storage timegt104 years σlt0004
MPa for wet σlt001 MPa for dry conditions Under σ=1 MPa failure occurs at 61 days for
wet 402 days for dry
Evans (1972) amp Nara et al (2015)
JOINTS modeling
17
bull Linear elastic Boundary element codebull Pseudo-3D accounts for elastic interaction
ndash Opening- and mixed-mode fracture propagationbull Allows simulation of fracture network development
as function of ndash Subcritical index (SCI) and KIC
ndash Elastic material propertiesndash Distribution of nucleation sites (seed fractures)
Plan and cross-section realizations
Dry CO2 DI water 1 NaCl 10 NaCl Acid
Woo
dfor
dM
arce
llus
JOINTS plan view
KIC (MParadicm)SCIνE (GPa)
100 m2
080690250
038140220
1195401528
1026401528
024140220
028110220
Qualitative differences in fracture network geometry in different chemical environmentsbull Number of fractures branching behavior curvature
1272601528
1185801528
029190220
Fracture aperture distributionCO2 003 mmDI 029 mm
Medians 1 NaCl 003 mm10 NaCl 029 mmAcid 028 mm
DI 024 mmMedians 1 NaCl 020 mm
10 NaCl 025 mmAcid 025 mm
Woo
dfor
dM
arce
llus
bull 1 NaCl Fewer but wider fractures
bull Acid More seeds activated but smaller aperture
bull Less spread in aperture range for different test environments than Woodford
JOINTS cross sections
Woodford 1 NaCl029 MParadicm 19 20 GPa
Woodford 10 NaCl024 MParadicm 14 20 GPa
2 m
10 m
Woodford DI water038 MParadicm 14 20 GPa
Woodford acid028 MParadicm 11 20 GPa
Woodford dry CO2
080 MParadicm 69 50 GPa
Summarybull Chemical environments rock mineralogy and temperature
influence shale fracture properties bull Larger wet-dry differences in clay-rich shales (Woodford and
Mancos) than in carbonate-rich shale (Marcellus)ndash ldquoWetrdquo fracture growth rate faster by one-order of magnitude
bull Increasing temperature enhances subcritical fracturingbull Carbonate-rich Marcellus carbonate dissolution
ndash SCI sensitive to acidic pHndash KIC independent of chemical environment
bull Woodford amp Mancos clay-water interactionndash KIC and SCI sensitive to water content and salinityndash Water-weakening enhances subcritical fracturing
bull Environmental effects controlled by competition between fracture growth rate and rate of rock degradation by fluid-rock interactions 21
Implications for CO2 seal integritybull Dry tests potentially applicable to dry scCO2 systems
ndash Dry-out by CO2 injection expected to strengthen caprock
bull Increasing caprock failure risk with increasing temperature
bull Clay-rich caprocksndash More pronounced dry-out effectndash Lower risk for seal failure by subcritical fracture growth
in scCO2 systemndash High salinity strengthens caprock
bull Carbonate-rich caprocksndash More prone to subcritical fracture by pH decrease
through dissolution of CO2 in brine22
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
Salinity
12
Woodford shale NaCl brine 23degC
Increase of fluid salinity increases KIC and SCI in clay-rich Woodford and Mancos shales
Less weakening in KCl brine than in NaCl brine Clay swelling
Uncoated
Coated
10-3
10-4
10-5
10-6
10-7
Stress Intensity Factor (MPa m12)
Frac
ture
Vel
ocity
(ms
)
0
02
04
06
0 03 06 09 12 15
K IC
(MPa
m1
2 )
Salt concentration (M)
NaClKCl
Coated
0
10
20
30
40
50
60
0 03 06 09 12 15
Subc
ritica
l Ind
exSalt concentration (M)
NaClKCl
Coated
Coated
pH
13
SCI decreases with decreasing pH for carbonate-rich Marcellus shale KIC is independent of pH SCI effect opposite to that in glass and quartzite Calcite dissolution
0
20
40
60
80
0 35 7 105 14Su
bcrit
ical I
ndex
pH
0
04
08
12
16
K IC
(MPa
m1
2 )
HCl H2O NaOH
Marcellus shale HCl solution 23degC
Temperature
14
Increase in temperature enhances subcritical fracturingbull Left-ward shift for all shalesbull Concentration effects less
2 minus 119899119899 11986011986012059012059021198841198842 1198701198701198681198681198681198682minus119899119899 minus 11987011987002minus119899119899
Constant stress loading
rArr
rArr
Assume subcritical crack growth limit 10-10 ms To meet safe storage timegt104 years σlt0004
MPa for wet σlt001 MPa for dry conditions Under σ=1 MPa failure occurs at 61 days for
wet 402 days for dry
Evans (1972) amp Nara et al (2015)
JOINTS modeling
17
bull Linear elastic Boundary element codebull Pseudo-3D accounts for elastic interaction
ndash Opening- and mixed-mode fracture propagationbull Allows simulation of fracture network development
as function of ndash Subcritical index (SCI) and KIC
ndash Elastic material propertiesndash Distribution of nucleation sites (seed fractures)
Plan and cross-section realizations
Dry CO2 DI water 1 NaCl 10 NaCl Acid
Woo
dfor
dM
arce
llus
JOINTS plan view
KIC (MParadicm)SCIνE (GPa)
100 m2
080690250
038140220
1195401528
1026401528
024140220
028110220
Qualitative differences in fracture network geometry in different chemical environmentsbull Number of fractures branching behavior curvature
1272601528
1185801528
029190220
Fracture aperture distributionCO2 003 mmDI 029 mm
Medians 1 NaCl 003 mm10 NaCl 029 mmAcid 028 mm
DI 024 mmMedians 1 NaCl 020 mm
10 NaCl 025 mmAcid 025 mm
Woo
dfor
dM
arce
llus
bull 1 NaCl Fewer but wider fractures
bull Acid More seeds activated but smaller aperture
bull Less spread in aperture range for different test environments than Woodford
JOINTS cross sections
Woodford 1 NaCl029 MParadicm 19 20 GPa
Woodford 10 NaCl024 MParadicm 14 20 GPa
2 m
10 m
Woodford DI water038 MParadicm 14 20 GPa
Woodford acid028 MParadicm 11 20 GPa
Woodford dry CO2
080 MParadicm 69 50 GPa
Summarybull Chemical environments rock mineralogy and temperature
influence shale fracture properties bull Larger wet-dry differences in clay-rich shales (Woodford and
Mancos) than in carbonate-rich shale (Marcellus)ndash ldquoWetrdquo fracture growth rate faster by one-order of magnitude
bull Increasing temperature enhances subcritical fracturingbull Carbonate-rich Marcellus carbonate dissolution
ndash SCI sensitive to acidic pHndash KIC independent of chemical environment
bull Woodford amp Mancos clay-water interactionndash KIC and SCI sensitive to water content and salinityndash Water-weakening enhances subcritical fracturing
bull Environmental effects controlled by competition between fracture growth rate and rate of rock degradation by fluid-rock interactions 21
Implications for CO2 seal integritybull Dry tests potentially applicable to dry scCO2 systems
ndash Dry-out by CO2 injection expected to strengthen caprock
bull Increasing caprock failure risk with increasing temperature
bull Clay-rich caprocksndash More pronounced dry-out effectndash Lower risk for seal failure by subcritical fracture growth
in scCO2 systemndash High salinity strengthens caprock
bull Carbonate-rich caprocksndash More prone to subcritical fracture by pH decrease
through dissolution of CO2 in brine22
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
pH
13
SCI decreases with decreasing pH for carbonate-rich Marcellus shale KIC is independent of pH SCI effect opposite to that in glass and quartzite Calcite dissolution
0
20
40
60
80
0 35 7 105 14Su
bcrit
ical I
ndex
pH
0
04
08
12
16
K IC
(MPa
m1
2 )
HCl H2O NaOH
Marcellus shale HCl solution 23degC
Temperature
14
Increase in temperature enhances subcritical fracturingbull Left-ward shift for all shalesbull Concentration effects less
2 minus 119899119899 11986011986012059012059021198841198842 1198701198701198681198681198681198682minus119899119899 minus 11987011987002minus119899119899
Constant stress loading
rArr
rArr
Assume subcritical crack growth limit 10-10 ms To meet safe storage timegt104 years σlt0004
MPa for wet σlt001 MPa for dry conditions Under σ=1 MPa failure occurs at 61 days for
wet 402 days for dry
Evans (1972) amp Nara et al (2015)
JOINTS modeling
17
bull Linear elastic Boundary element codebull Pseudo-3D accounts for elastic interaction
ndash Opening- and mixed-mode fracture propagationbull Allows simulation of fracture network development
as function of ndash Subcritical index (SCI) and KIC
ndash Elastic material propertiesndash Distribution of nucleation sites (seed fractures)
Plan and cross-section realizations
Dry CO2 DI water 1 NaCl 10 NaCl Acid
Woo
dfor
dM
arce
llus
JOINTS plan view
KIC (MParadicm)SCIνE (GPa)
100 m2
080690250
038140220
1195401528
1026401528
024140220
028110220
Qualitative differences in fracture network geometry in different chemical environmentsbull Number of fractures branching behavior curvature
1272601528
1185801528
029190220
Fracture aperture distributionCO2 003 mmDI 029 mm
Medians 1 NaCl 003 mm10 NaCl 029 mmAcid 028 mm
DI 024 mmMedians 1 NaCl 020 mm
10 NaCl 025 mmAcid 025 mm
Woo
dfor
dM
arce
llus
bull 1 NaCl Fewer but wider fractures
bull Acid More seeds activated but smaller aperture
bull Less spread in aperture range for different test environments than Woodford
JOINTS cross sections
Woodford 1 NaCl029 MParadicm 19 20 GPa
Woodford 10 NaCl024 MParadicm 14 20 GPa
2 m
10 m
Woodford DI water038 MParadicm 14 20 GPa
Woodford acid028 MParadicm 11 20 GPa
Woodford dry CO2
080 MParadicm 69 50 GPa
Summarybull Chemical environments rock mineralogy and temperature
influence shale fracture properties bull Larger wet-dry differences in clay-rich shales (Woodford and
Mancos) than in carbonate-rich shale (Marcellus)ndash ldquoWetrdquo fracture growth rate faster by one-order of magnitude
bull Increasing temperature enhances subcritical fracturingbull Carbonate-rich Marcellus carbonate dissolution
ndash SCI sensitive to acidic pHndash KIC independent of chemical environment
bull Woodford amp Mancos clay-water interactionndash KIC and SCI sensitive to water content and salinityndash Water-weakening enhances subcritical fracturing
bull Environmental effects controlled by competition between fracture growth rate and rate of rock degradation by fluid-rock interactions 21
Implications for CO2 seal integritybull Dry tests potentially applicable to dry scCO2 systems
ndash Dry-out by CO2 injection expected to strengthen caprock
bull Increasing caprock failure risk with increasing temperature
bull Clay-rich caprocksndash More pronounced dry-out effectndash Lower risk for seal failure by subcritical fracture growth
in scCO2 systemndash High salinity strengthens caprock
bull Carbonate-rich caprocksndash More prone to subcritical fracture by pH decrease
through dissolution of CO2 in brine22
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
Temperature
14
Increase in temperature enhances subcritical fracturingbull Left-ward shift for all shalesbull Concentration effects less
2 minus 119899119899 11986011986012059012059021198841198842 1198701198701198681198681198681198682minus119899119899 minus 11987011987002minus119899119899
Constant stress loading
rArr
rArr
Assume subcritical crack growth limit 10-10 ms To meet safe storage timegt104 years σlt0004
MPa for wet σlt001 MPa for dry conditions Under σ=1 MPa failure occurs at 61 days for
wet 402 days for dry
Evans (1972) amp Nara et al (2015)
JOINTS modeling
17
bull Linear elastic Boundary element codebull Pseudo-3D accounts for elastic interaction
ndash Opening- and mixed-mode fracture propagationbull Allows simulation of fracture network development
as function of ndash Subcritical index (SCI) and KIC
ndash Elastic material propertiesndash Distribution of nucleation sites (seed fractures)
Plan and cross-section realizations
Dry CO2 DI water 1 NaCl 10 NaCl Acid
Woo
dfor
dM
arce
llus
JOINTS plan view
KIC (MParadicm)SCIνE (GPa)
100 m2
080690250
038140220
1195401528
1026401528
024140220
028110220
Qualitative differences in fracture network geometry in different chemical environmentsbull Number of fractures branching behavior curvature
1272601528
1185801528
029190220
Fracture aperture distributionCO2 003 mmDI 029 mm
Medians 1 NaCl 003 mm10 NaCl 029 mmAcid 028 mm
DI 024 mmMedians 1 NaCl 020 mm
10 NaCl 025 mmAcid 025 mm
Woo
dfor
dM
arce
llus
bull 1 NaCl Fewer but wider fractures
bull Acid More seeds activated but smaller aperture
bull Less spread in aperture range for different test environments than Woodford
JOINTS cross sections
Woodford 1 NaCl029 MParadicm 19 20 GPa
Woodford 10 NaCl024 MParadicm 14 20 GPa
2 m
10 m
Woodford DI water038 MParadicm 14 20 GPa
Woodford acid028 MParadicm 11 20 GPa
Woodford dry CO2
080 MParadicm 69 50 GPa
Summarybull Chemical environments rock mineralogy and temperature
influence shale fracture properties bull Larger wet-dry differences in clay-rich shales (Woodford and
Mancos) than in carbonate-rich shale (Marcellus)ndash ldquoWetrdquo fracture growth rate faster by one-order of magnitude
bull Increasing temperature enhances subcritical fracturingbull Carbonate-rich Marcellus carbonate dissolution
ndash SCI sensitive to acidic pHndash KIC independent of chemical environment
bull Woodford amp Mancos clay-water interactionndash KIC and SCI sensitive to water content and salinityndash Water-weakening enhances subcritical fracturing
bull Environmental effects controlled by competition between fracture growth rate and rate of rock degradation by fluid-rock interactions 21
Implications for CO2 seal integritybull Dry tests potentially applicable to dry scCO2 systems
ndash Dry-out by CO2 injection expected to strengthen caprock
bull Increasing caprock failure risk with increasing temperature
bull Clay-rich caprocksndash More pronounced dry-out effectndash Lower risk for seal failure by subcritical fracture growth
in scCO2 systemndash High salinity strengthens caprock
bull Carbonate-rich caprocksndash More prone to subcritical fracture by pH decrease
through dissolution of CO2 in brine22
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
2 minus 119899119899 11986011986012059012059021198841198842 1198701198701198681198681198681198682minus119899119899 minus 11987011987002minus119899119899
Constant stress loading
rArr
rArr
Assume subcritical crack growth limit 10-10 ms To meet safe storage timegt104 years σlt0004
MPa for wet σlt001 MPa for dry conditions Under σ=1 MPa failure occurs at 61 days for
wet 402 days for dry
Evans (1972) amp Nara et al (2015)
JOINTS modeling
17
bull Linear elastic Boundary element codebull Pseudo-3D accounts for elastic interaction
ndash Opening- and mixed-mode fracture propagationbull Allows simulation of fracture network development
as function of ndash Subcritical index (SCI) and KIC
ndash Elastic material propertiesndash Distribution of nucleation sites (seed fractures)
Plan and cross-section realizations
Dry CO2 DI water 1 NaCl 10 NaCl Acid
Woo
dfor
dM
arce
llus
JOINTS plan view
KIC (MParadicm)SCIνE (GPa)
100 m2
080690250
038140220
1195401528
1026401528
024140220
028110220
Qualitative differences in fracture network geometry in different chemical environmentsbull Number of fractures branching behavior curvature
1272601528
1185801528
029190220
Fracture aperture distributionCO2 003 mmDI 029 mm
Medians 1 NaCl 003 mm10 NaCl 029 mmAcid 028 mm
DI 024 mmMedians 1 NaCl 020 mm
10 NaCl 025 mmAcid 025 mm
Woo
dfor
dM
arce
llus
bull 1 NaCl Fewer but wider fractures
bull Acid More seeds activated but smaller aperture
bull Less spread in aperture range for different test environments than Woodford
JOINTS cross sections
Woodford 1 NaCl029 MParadicm 19 20 GPa
Woodford 10 NaCl024 MParadicm 14 20 GPa
2 m
10 m
Woodford DI water038 MParadicm 14 20 GPa
Woodford acid028 MParadicm 11 20 GPa
Woodford dry CO2
080 MParadicm 69 50 GPa
Summarybull Chemical environments rock mineralogy and temperature
influence shale fracture properties bull Larger wet-dry differences in clay-rich shales (Woodford and
Mancos) than in carbonate-rich shale (Marcellus)ndash ldquoWetrdquo fracture growth rate faster by one-order of magnitude
bull Increasing temperature enhances subcritical fracturingbull Carbonate-rich Marcellus carbonate dissolution
ndash SCI sensitive to acidic pHndash KIC independent of chemical environment
bull Woodford amp Mancos clay-water interactionndash KIC and SCI sensitive to water content and salinityndash Water-weakening enhances subcritical fracturing
bull Environmental effects controlled by competition between fracture growth rate and rate of rock degradation by fluid-rock interactions 21
Implications for CO2 seal integritybull Dry tests potentially applicable to dry scCO2 systems
ndash Dry-out by CO2 injection expected to strengthen caprock
bull Increasing caprock failure risk with increasing temperature
bull Clay-rich caprocksndash More pronounced dry-out effectndash Lower risk for seal failure by subcritical fracture growth
in scCO2 systemndash High salinity strengthens caprock
bull Carbonate-rich caprocksndash More prone to subcritical fracture by pH decrease
through dissolution of CO2 in brine22
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
2 minus 119899119899 11986011986012059012059021198841198842 1198701198701198681198681198681198682minus119899119899 minus 11987011987002minus119899119899
Constant stress loading
rArr
rArr
Assume subcritical crack growth limit 10-10 ms To meet safe storage timegt104 years σlt0004
MPa for wet σlt001 MPa for dry conditions Under σ=1 MPa failure occurs at 61 days for
wet 402 days for dry
Evans (1972) amp Nara et al (2015)
JOINTS modeling
17
bull Linear elastic Boundary element codebull Pseudo-3D accounts for elastic interaction
ndash Opening- and mixed-mode fracture propagationbull Allows simulation of fracture network development
as function of ndash Subcritical index (SCI) and KIC
ndash Elastic material propertiesndash Distribution of nucleation sites (seed fractures)
Plan and cross-section realizations
Dry CO2 DI water 1 NaCl 10 NaCl Acid
Woo
dfor
dM
arce
llus
JOINTS plan view
KIC (MParadicm)SCIνE (GPa)
100 m2
080690250
038140220
1195401528
1026401528
024140220
028110220
Qualitative differences in fracture network geometry in different chemical environmentsbull Number of fractures branching behavior curvature
1272601528
1185801528
029190220
Fracture aperture distributionCO2 003 mmDI 029 mm
Medians 1 NaCl 003 mm10 NaCl 029 mmAcid 028 mm
DI 024 mmMedians 1 NaCl 020 mm
10 NaCl 025 mmAcid 025 mm
Woo
dfor
dM
arce
llus
bull 1 NaCl Fewer but wider fractures
bull Acid More seeds activated but smaller aperture
bull Less spread in aperture range for different test environments than Woodford
JOINTS cross sections
Woodford 1 NaCl029 MParadicm 19 20 GPa
Woodford 10 NaCl024 MParadicm 14 20 GPa
2 m
10 m
Woodford DI water038 MParadicm 14 20 GPa
Woodford acid028 MParadicm 11 20 GPa
Woodford dry CO2
080 MParadicm 69 50 GPa
Summarybull Chemical environments rock mineralogy and temperature
influence shale fracture properties bull Larger wet-dry differences in clay-rich shales (Woodford and
Mancos) than in carbonate-rich shale (Marcellus)ndash ldquoWetrdquo fracture growth rate faster by one-order of magnitude
bull Increasing temperature enhances subcritical fracturingbull Carbonate-rich Marcellus carbonate dissolution
ndash SCI sensitive to acidic pHndash KIC independent of chemical environment
bull Woodford amp Mancos clay-water interactionndash KIC and SCI sensitive to water content and salinityndash Water-weakening enhances subcritical fracturing
bull Environmental effects controlled by competition between fracture growth rate and rate of rock degradation by fluid-rock interactions 21
Implications for CO2 seal integritybull Dry tests potentially applicable to dry scCO2 systems
ndash Dry-out by CO2 injection expected to strengthen caprock
bull Increasing caprock failure risk with increasing temperature
bull Clay-rich caprocksndash More pronounced dry-out effectndash Lower risk for seal failure by subcritical fracture growth
in scCO2 systemndash High salinity strengthens caprock
bull Carbonate-rich caprocksndash More prone to subcritical fracture by pH decrease
through dissolution of CO2 in brine22
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
JOINTS modeling
17
bull Linear elastic Boundary element codebull Pseudo-3D accounts for elastic interaction
ndash Opening- and mixed-mode fracture propagationbull Allows simulation of fracture network development
as function of ndash Subcritical index (SCI) and KIC
ndash Elastic material propertiesndash Distribution of nucleation sites (seed fractures)
Plan and cross-section realizations
Dry CO2 DI water 1 NaCl 10 NaCl Acid
Woo
dfor
dM
arce
llus
JOINTS plan view
KIC (MParadicm)SCIνE (GPa)
100 m2
080690250
038140220
1195401528
1026401528
024140220
028110220
Qualitative differences in fracture network geometry in different chemical environmentsbull Number of fractures branching behavior curvature
1272601528
1185801528
029190220
Fracture aperture distributionCO2 003 mmDI 029 mm
Medians 1 NaCl 003 mm10 NaCl 029 mmAcid 028 mm
DI 024 mmMedians 1 NaCl 020 mm
10 NaCl 025 mmAcid 025 mm
Woo
dfor
dM
arce
llus
bull 1 NaCl Fewer but wider fractures
bull Acid More seeds activated but smaller aperture
bull Less spread in aperture range for different test environments than Woodford
JOINTS cross sections
Woodford 1 NaCl029 MParadicm 19 20 GPa
Woodford 10 NaCl024 MParadicm 14 20 GPa
2 m
10 m
Woodford DI water038 MParadicm 14 20 GPa
Woodford acid028 MParadicm 11 20 GPa
Woodford dry CO2
080 MParadicm 69 50 GPa
Summarybull Chemical environments rock mineralogy and temperature
influence shale fracture properties bull Larger wet-dry differences in clay-rich shales (Woodford and
Mancos) than in carbonate-rich shale (Marcellus)ndash ldquoWetrdquo fracture growth rate faster by one-order of magnitude
bull Increasing temperature enhances subcritical fracturingbull Carbonate-rich Marcellus carbonate dissolution
ndash SCI sensitive to acidic pHndash KIC independent of chemical environment
bull Woodford amp Mancos clay-water interactionndash KIC and SCI sensitive to water content and salinityndash Water-weakening enhances subcritical fracturing
bull Environmental effects controlled by competition between fracture growth rate and rate of rock degradation by fluid-rock interactions 21
Implications for CO2 seal integritybull Dry tests potentially applicable to dry scCO2 systems
ndash Dry-out by CO2 injection expected to strengthen caprock
bull Increasing caprock failure risk with increasing temperature
bull Clay-rich caprocksndash More pronounced dry-out effectndash Lower risk for seal failure by subcritical fracture growth
in scCO2 systemndash High salinity strengthens caprock
bull Carbonate-rich caprocksndash More prone to subcritical fracture by pH decrease
through dissolution of CO2 in brine22
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
Dry CO2 DI water 1 NaCl 10 NaCl Acid
Woo
dfor
dM
arce
llus
JOINTS plan view
KIC (MParadicm)SCIνE (GPa)
100 m2
080690250
038140220
1195401528
1026401528
024140220
028110220
Qualitative differences in fracture network geometry in different chemical environmentsbull Number of fractures branching behavior curvature
1272601528
1185801528
029190220
Fracture aperture distributionCO2 003 mmDI 029 mm
Medians 1 NaCl 003 mm10 NaCl 029 mmAcid 028 mm
DI 024 mmMedians 1 NaCl 020 mm
10 NaCl 025 mmAcid 025 mm
Woo
dfor
dM
arce
llus
bull 1 NaCl Fewer but wider fractures
bull Acid More seeds activated but smaller aperture
bull Less spread in aperture range for different test environments than Woodford
JOINTS cross sections
Woodford 1 NaCl029 MParadicm 19 20 GPa
Woodford 10 NaCl024 MParadicm 14 20 GPa
2 m
10 m
Woodford DI water038 MParadicm 14 20 GPa
Woodford acid028 MParadicm 11 20 GPa
Woodford dry CO2
080 MParadicm 69 50 GPa
Summarybull Chemical environments rock mineralogy and temperature
influence shale fracture properties bull Larger wet-dry differences in clay-rich shales (Woodford and
Mancos) than in carbonate-rich shale (Marcellus)ndash ldquoWetrdquo fracture growth rate faster by one-order of magnitude
bull Increasing temperature enhances subcritical fracturingbull Carbonate-rich Marcellus carbonate dissolution
ndash SCI sensitive to acidic pHndash KIC independent of chemical environment
bull Woodford amp Mancos clay-water interactionndash KIC and SCI sensitive to water content and salinityndash Water-weakening enhances subcritical fracturing
bull Environmental effects controlled by competition between fracture growth rate and rate of rock degradation by fluid-rock interactions 21
Implications for CO2 seal integritybull Dry tests potentially applicable to dry scCO2 systems
ndash Dry-out by CO2 injection expected to strengthen caprock
bull Increasing caprock failure risk with increasing temperature
bull Clay-rich caprocksndash More pronounced dry-out effectndash Lower risk for seal failure by subcritical fracture growth
in scCO2 systemndash High salinity strengthens caprock
bull Carbonate-rich caprocksndash More prone to subcritical fracture by pH decrease
through dissolution of CO2 in brine22
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
Fracture aperture distributionCO2 003 mmDI 029 mm
Medians 1 NaCl 003 mm10 NaCl 029 mmAcid 028 mm
DI 024 mmMedians 1 NaCl 020 mm
10 NaCl 025 mmAcid 025 mm
Woo
dfor
dM
arce
llus
bull 1 NaCl Fewer but wider fractures
bull Acid More seeds activated but smaller aperture
bull Less spread in aperture range for different test environments than Woodford
JOINTS cross sections
Woodford 1 NaCl029 MParadicm 19 20 GPa
Woodford 10 NaCl024 MParadicm 14 20 GPa
2 m
10 m
Woodford DI water038 MParadicm 14 20 GPa
Woodford acid028 MParadicm 11 20 GPa
Woodford dry CO2
080 MParadicm 69 50 GPa
Summarybull Chemical environments rock mineralogy and temperature
influence shale fracture properties bull Larger wet-dry differences in clay-rich shales (Woodford and
Mancos) than in carbonate-rich shale (Marcellus)ndash ldquoWetrdquo fracture growth rate faster by one-order of magnitude
bull Increasing temperature enhances subcritical fracturingbull Carbonate-rich Marcellus carbonate dissolution
ndash SCI sensitive to acidic pHndash KIC independent of chemical environment
bull Woodford amp Mancos clay-water interactionndash KIC and SCI sensitive to water content and salinityndash Water-weakening enhances subcritical fracturing
bull Environmental effects controlled by competition between fracture growth rate and rate of rock degradation by fluid-rock interactions 21
Implications for CO2 seal integritybull Dry tests potentially applicable to dry scCO2 systems
ndash Dry-out by CO2 injection expected to strengthen caprock
bull Increasing caprock failure risk with increasing temperature
bull Clay-rich caprocksndash More pronounced dry-out effectndash Lower risk for seal failure by subcritical fracture growth
in scCO2 systemndash High salinity strengthens caprock
bull Carbonate-rich caprocksndash More prone to subcritical fracture by pH decrease
through dissolution of CO2 in brine22
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
JOINTS cross sections
Woodford 1 NaCl029 MParadicm 19 20 GPa
Woodford 10 NaCl024 MParadicm 14 20 GPa
2 m
10 m
Woodford DI water038 MParadicm 14 20 GPa
Woodford acid028 MParadicm 11 20 GPa
Woodford dry CO2
080 MParadicm 69 50 GPa
Summarybull Chemical environments rock mineralogy and temperature
influence shale fracture properties bull Larger wet-dry differences in clay-rich shales (Woodford and
Mancos) than in carbonate-rich shale (Marcellus)ndash ldquoWetrdquo fracture growth rate faster by one-order of magnitude
bull Increasing temperature enhances subcritical fracturingbull Carbonate-rich Marcellus carbonate dissolution
ndash SCI sensitive to acidic pHndash KIC independent of chemical environment
bull Woodford amp Mancos clay-water interactionndash KIC and SCI sensitive to water content and salinityndash Water-weakening enhances subcritical fracturing
bull Environmental effects controlled by competition between fracture growth rate and rate of rock degradation by fluid-rock interactions 21
Implications for CO2 seal integritybull Dry tests potentially applicable to dry scCO2 systems
ndash Dry-out by CO2 injection expected to strengthen caprock
bull Increasing caprock failure risk with increasing temperature
bull Clay-rich caprocksndash More pronounced dry-out effectndash Lower risk for seal failure by subcritical fracture growth
in scCO2 systemndash High salinity strengthens caprock
bull Carbonate-rich caprocksndash More prone to subcritical fracture by pH decrease
through dissolution of CO2 in brine22
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
Summarybull Chemical environments rock mineralogy and temperature
influence shale fracture properties bull Larger wet-dry differences in clay-rich shales (Woodford and
Mancos) than in carbonate-rich shale (Marcellus)ndash ldquoWetrdquo fracture growth rate faster by one-order of magnitude
bull Increasing temperature enhances subcritical fracturingbull Carbonate-rich Marcellus carbonate dissolution
ndash SCI sensitive to acidic pHndash KIC independent of chemical environment
bull Woodford amp Mancos clay-water interactionndash KIC and SCI sensitive to water content and salinityndash Water-weakening enhances subcritical fracturing
bull Environmental effects controlled by competition between fracture growth rate and rate of rock degradation by fluid-rock interactions 21
Implications for CO2 seal integritybull Dry tests potentially applicable to dry scCO2 systems
ndash Dry-out by CO2 injection expected to strengthen caprock
bull Increasing caprock failure risk with increasing temperature
bull Clay-rich caprocksndash More pronounced dry-out effectndash Lower risk for seal failure by subcritical fracture growth
in scCO2 systemndash High salinity strengthens caprock
bull Carbonate-rich caprocksndash More prone to subcritical fracture by pH decrease
through dissolution of CO2 in brine22
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
Implications for CO2 seal integritybull Dry tests potentially applicable to dry scCO2 systems
ndash Dry-out by CO2 injection expected to strengthen caprock
bull Increasing caprock failure risk with increasing temperature
bull Clay-rich caprocksndash More pronounced dry-out effectndash Lower risk for seal failure by subcritical fracture growth
in scCO2 systemndash High salinity strengthens caprock
bull Carbonate-rich caprocksndash More prone to subcritical fracture by pH decrease
through dissolution of CO2 in brine22
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
Accomplishments to Date
bull Fracture mechanics testing on caprock lithologies in dry amp aqueous environments of varying composition varying temperature
bull Numerical simulations on fracture network evolution by chemically aided fracture growth
bull Simulated caprock leakage behavior using continuum models for varying well reservoircaprock geometry
23
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
Next steps (in progress)
bull Short-rod fracture testing under confinement with scCO2
bull Upscaled seal failure amp leakage simulations ndash Integration of continuum amp fracture network
modeling
24
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
Synergy Opportunities
bull Fracture mechanics analysis of Cranfieldand FutureGen II core material
bull Integration with tests of frictional behavior under chemically reactive conditions
bull Integration of results with fracture network modeling (phase-field cohesive end-zone peridynamics)
bull Integration with hydraulic fracture research
25
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
Appendix
26
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
27
Benefit to the Program bull Program goals Develop characterization tools technologies andor
methodologies that improve the ability to predict geologic storage capacity within plusmn30 improve the utilization of the reservoir by understanding how faults and fractures in a reservoir affect the flow of CO2 and ensure storage permanencendash Area of Interest 2 ndash Fractured Reservoir and Seal Behavior Develop
tools and techniques to increase the accuracy and reduce the costs of assessing subsurface seal containment and the sealreservoir interface including the measurement of in-situ rock properties in order to develop a better understanding of seal behavior when CO2 is injected into a reservoir
bull Project is designed to ndash Provide calibrated and validated numerical predictive
tools for long-term prediction of reservoir seal integrity beyond the engineering (injection) time scale
ndash Contribute toward technology ensuring 99 storage permanence in the injection zone for 1000 years
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
28
Project Overview Goals and Objectives
bull Perform laboratory fracture mechanics testing to ndash gain fundamental understanding into fracture processes in chemically
reactive systems and to ndash provide input parameters on fracture constitutive behavior fracture
rate and geometry and deformation and transport processes involved in subcritical chemically assisted fracture growth for relevant top seal lithologies
bull Derive predictive and validated numerical models for fracture growth in chemically reactive environments relevant to CCUS top seal lithologies
bull Validate numerical amp laboratory observations against microstructural and textural observations on fractures from natural CO2 seeps
bull Perform upscaled numerical simulations that are informed by field and lab results toward predictive tools for top seal integrity analysis top seal mechanical failure and impact on CO2 leakage in CCUS applications
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
29
Organization Chart Communication Plan
bull Established Sandia-UT collaborationbull Olson ndashndash Eichhubl on joint industry projectsbull Dewers ndash Newell ndashEichhubl on joint EFRC
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
Gantt Chart
Short-rod tests (task 21) are being performed under task 23 under confined conditions No-cost extension pending following discontinuity of funding for Sandia in PY 17
91
2014
-12
312
014
11
2015
-33
120
154
120
15-6
30
2015
71
2015
-93
020
1510
12
015-
123
120
151
120
16-3
31
2016
41
2016
-63
020
167
120
16-9
30
2016
101
201
6-12
31
2016
11
2017
-33
120
174
120
17-6
30
2017
71
2017
-83
120
1710
12
017-
123
120
171
120
18-2
31
2018
1 Project Management and Planning p p p21 Short rod fracture toughness tests 22 Double torsion tests p p23 Fracturing in water-bearing supercritical CO2 p p31 Field fracture characterization
32 Textural and compositional fracture imaging
41 Discrete fracture modeling using Sierra Mechanics p p p42 Fracture network modeling using JOINTS p p p43 Upscaled modeling using Kayenta
5 Model validation and integration p p p
TaskSubtask
Year 1 Year 2 Year 3 Year 4
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
Time-to-failure analysis
Mt Simon Sandstone
Sample Characterization
Mt Simon Ss
Slide Number 44
Mt Simon fracture mechanics
Mt Simon fracture mechanics
Refs
Accomplishments to Date
Synergy Opportunities
Lessons Learned
Project Summary
Benefit to the Program
Bibliographybull Journal multiple authors
ndash P Newell M J Martinez P Eichhubl 2016 Impact of layer thickness and well orientation on caprock integrity for geologic carbon storage Journal of Petroleum Science and Engineering available at httpdoi101016jpetrol201607032
ndash Chen X Eichhubl P Olson J E 2017 Effect of water on critical and subcritical fracture properties of Woodford shale Journal of Geophysical Research-Solid Earth v 122 httpdxdoiorg1010022016JB013708
Area of Interest 2 Geomechanics of CO2 Reservoir SealsDE-FE0023316
Problem Statement
Permeability structure of conduit-barrier fault zone
Fractures in CO2 caprockCrystal Geyser field analog site
Methodology
Mode-I fracture testing
Testing protocol
Shale sample composition
Fracture trace imaging
Fracture surface imaging
Water content
Salinity
pH
Temperature
Summary of K-V relations
Time-to-failure analysis
JOINTS modeling
JOINTS plan view
Fracture aperture distribution
JOINTS cross sections
Summary
Implications for CO2 seal integrity
Accomplishments to Date
Next steps (in progress)
Synergy Opportunities
Appendix
Benefit to the Program
Project Overview Goals and Objectives
Organization Chart Communication Plan
Gantt Chart
Bibliography
Extra slides not for posting
Transient effect
Presentation Outline
Introduction
pH effect
Natural fracture networksMancos Shale at Crystal Geyser
