Methods & Advancements in Hydraulic Fracturing Technologies...

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Methods & Advancements in Hydraulic Fracturing Technologies as Applied to In-Situ Biological and Chemical Remediation

Vincent E. Barlock P.G . &

John Fontana P.G.

Hydraulic Fracturing

(hydrofracturing/fractuirng/fracing)

– A Down-Hole Process by which the

Existing Subsurface Lithologies, Porosity,

or Fracture Network is Artificially

Enhanced (Fractured) by the Injection of

Fluids, Air, or Steam Under Very High

Pressure

– Was Originally Developed for the Oil and

Gas Industry. Initial concept as far back as

O&G Well Heads Equipped for Hydraulic Fracturing.Technology undertaken at depths between 2,000 and 20,000 feet bgs.

O&G Depths: typically >2,000 ft

Massive Infrastructure Needs

The Up-Side of Hydraulic Fracturing to Environmental Remediation

• Enhanced Injection of Remedial Fluids/Solids

• Enhanced Recovery of Impacted Fluids

• Enhanced Porosity and Storage to improve

remediation success

• Enhanced Radius-Of-Influence

• Decreased Capital Cost & Long-Term O&M

Temporal Changes in Hydraulic Fracturing• The Technology has been taken to shallow depths

(i.e. 150 to 4 feet bgs) and effectively implemented

for remediation since the mid-1980s.

• 1980-1990: Simple single fractures; horizontal;

limited volumes, limited R.O.I monitoring.

• 1990-2000: D.O.E & D.O.D- funded grants for

Multiple fractures per boring; larger volumes;

horizontal and vertical; enhanced R.O.I monitoring.

• 2000- 2010: Diversity of Proppants; Fracturing in of

Pure remedial compounds; 3D modeling of

fractures; Emplaced in more difficult geology

UST Sites Refineries

So - What Sites are Being Hydraulic Fractured ?

D.O.D & NASAFacilities

(D.F.C, P.C.D, R.A)

Solid Waste FacilitiesMilitary and Private

Industrial /CommercialFacilities

Pueblo Chemical DepotPueblo, CO.

•2.4 Million

Gallons of EVO

injected

•~ 600Points

• THE REAL QUESTIONS ARE:

• WHAT is the Ultimate Purpose(s) of the Fractures? Both Short- and Long-term.

• WHAT Method of Fracture Emplacement is Best Suited to Meet This Purpose? And

• WHAT Are the Key Factors Affecting the Method Selected?

• Effective Implementation And Successful

Remediation Is Directly Related To Strategic

Targeting Of Fractures Under Ideal Site Conditions

• Host Rock, Depth of Impact, Vertical &

Horizontal Extent of Impact, and Contaminant

Mass must be known.

So How Does One Proceed ?

HOWEVER THIS IS RARELY THE CASE

(1) HYDRO GEOLOGY

•Tightness (i.e., low “K” of the lithologic units);

• Lithologic heterogeneity:

• Shale, siltstone/claystone, limestone, etc.

• Cohesiveness of unconsolidated soils; plasticity;

• Degree of cementation/induration;

• Flow direction & Magnitude

(2) PROXIMITY TO STRUCTURE•Anthropomorphic (bldgs., pools, utilities)

•Geologic (faults, antiforms/synforms, joints/fractures)

(3) CAN YOU MAINTAIN YOUR SEAL DURING

FRACTURING?

Key Factors Affecting Hydraulic Fracturing Method Selection

Key Factors That Adversely Affect Fracturing Method Selection

• Where and how are the impacts distributed in the

subsurface (i.e., COCs in discrete intervals or large

smear zones) ??

• Very shallow 2-10 feet vs: 10 -100 ft

• COC Distribution (Spotty or massive)

• Conflicting reports and questionable data;

• Poor logging/sampling techniques; incorrect soil/rock

classifications;

• Difficult geology: fractured bedrock; massive or

heterogeneous soils

SO Which Method Is It ??

Direct Push or Packers, or a Combination ?

•DPT Method Best for Emplacement of

Fractures in Unconsolidated Materials

Courtesy of Foremost

Conceptualized DPT Emplaced Bionets ™/Fractures at a UST Site

•Courtesy V. Barlock / Paul Willet

DPT - Dual WallDPT Points with Ground Monitoring

Courteous of Foremost

EPA & Foremost 1995 Introduced Fracturing at the Denver Federal Center

•EPA & Others emplaced

multiple hydraulic fractures at

the Center to remediate

groundwater impacts.

• The DFC was the Site of the

first enhanced in-situ

bioremediation system utilizing

hydraulic fracturing with Isolite

as both the proppant and pre-

inoculated carrier of indigenous

microbes and nutrients.

• In 2009 Sites at the DFC

were again hydraulically

fractured using DPT methods.

18Courtesy USGS

DFC – 2009

Fracturing and KMnO4

Injections Via DPT methods:

(Mactec/Vista GeoScience)

• 217 Fractures

completed in Denver

Formation

•Approximately 300K

Gallons of Potassium

Permanganate Injected

Packers w H.S.A Drilling Typically Best for Bedrock, & Semi-Consoldated Soil

20•Typical Bedrock Sandstone in Denver Formation

•Courtesy TAM International

Packer Method - Equipment• Drills

– Hollow-Stem- Auger

– Rotary

• Mud

• Air

– Dual DPT/H.S.A

• Pumps

• Progressive Cavity

• Double Diaphragm

• Piston

• Mixers

• Hoppers

• Augers

Various In-Situ Injection/Fracture Rigs

90% of Fracture Rigs in U.S. Today Emplace Fractures Using Guar-gum as Breaking Fluid and Carrier

•Courtesy Foremost

Hydraulic Kerfing. Is it Required?

Straddle-Packer Technology for Fracture and Proppant Emplacement

•Video & Animation Courtesy: Mr. Paul Willett

Advances in Hydraulic Fracture Remediation

• Bionets ™ and Fractures for Enhanced Injection /

Extraction

• PROPPANTS:

– Permanent: Proppant stays in the fracture and is not

degraded over time

• (i.e., porous ceramics; silica sands; synthetics)

– Temporary: Proppant degrades over time

• (i.e., chitin, solid oxidants [i.e., K MnO4])

• FRACTURE MONITORING

– Survey and Rods for Radius of Influence (R.O.I)

– Enhanced Real-time 3D modeling for R.O.I

Direct Advances

• BIOREMEDIATION

• (Bio-stimulation & Bio-augmentation via fractures)

• Pre-inoculated support matrices using commercially available

inoculums

• Emplacement of Bio-augmented Reactive Lenses/Fractures or

Reactive Columns

• Enhance and “Sustain” bioactivity with primary organic

nutrient formulation injections via either DPT of hydraulic

fractures

Direct Advances in Hydraulic Fracture Remediation (cont.)

Proppants (Permanent)

• Silica Sand

• (Most Widely use

Proppant)No. 10/20 mesh

– (Ne ~25-32%)

Example of an Emplaced Sand Fracture/BioNet ™

•EPA Site: (Foremost Solutions)

Proppants (Permanent)• Isolite – Porous Ceramic

– 1 gram = 55 ft 2 surface

– Can house up to 100M

microbes

– 0.5-2 mm (Ne ~ 54-62%)

Emplaced Isolite Fracture/Bionet ™EPA Site: (Foremost Solutions)

Proppants (Permanent)

• Various Resin-coated

Silica Beads

– (Ne ~32%)

– Reduced Friction &

Enhanced flow

Proppants (Temporary)

•Courtesy EPA

• IRON

• Zero Valent Iron

• Chitin (Polysaccharide)

• A class of carbohydrates, such as starch and cellulose

•Courtesy EPA

• Solid Oxidants (Potassium

Permanganate- KMnO4)

•Courtesy EPA

•Courtesy Carus Chemicals

Fracture Monitoring Advances

Past:Visual Inspection of Tilt-

Rods to measure ground

displacement

Current:

Survey & Rod

To measure ground

displacement (Pre & Post)

Advances in R.O.I Monitoring

Real-Time:Sensitive Tilt Meters for

Monitoring Ground

Deformation in Real Time

(Mid 1990’s to Current)

Advances in R.O.I Injection Monitoring Technology

•Conventional Bi-axial •Future Wireless

• Very Sensitive • Quickly Deployed•Courtesy Slope Indicator Inc.,

Characteristic Temporal Injection / Hydraulic Fracture Tilt Meter Responses

Monitoring Advances In Fracture / Bionet ™ Imaging

•Accurate GIS Mapping

of Monitoring Array

• 3D Plots of Inferred

Fracture Morphology

and ROI.

Indirect Advances

•Enhanced Vertical Profiling to Target Fracture:

– MEMBRANE INTERFACE PROBE (MIP)

– (Example Presented)

– Fiber optic & Laser detection

– PDBs / Permeable membrane technology

– Heat-pulse or electromagnetic boreholeflow meters

•Fracture/ Bionet ™ Mapping/Delineation

•Tilt meters

•Conventional and new wireless tech.

•Electrical Resistance Mapping

Membrane Interface Probe

• Real-time In the field modifications to

proposed fracture locations and

depths.

Initial MIP investigation 2008

• Initial Location of Source

• Clays (CL) and Silts (ML)

• Bedrock surface w/

• Aquifer (SP/SW)

Enhanced MIP investigation 2009. Can Now Strategically Target Fractures/Injections

•The Smoking Gun!!

(PCE neutralization

tanks )

• Located the

Vertical Conduit to

Bedrock surface

w/ DNAPL

• Initial Location of

Source (PCE)

•Courtesy Columbia Technologies

Resistivity Monitoring

1980’s 2010

Typical No. of Fractures per Boring 1 1 to 5

Casings per Boring 1 1 to 4

Sand Injected (lbs) 500-2000 500-40,000

Delta Storage Created / Fracture (ft3) 5 to 20 5 to 400

Average range in R.O.I (ft) 5 to 45 5 to 175

Porosity / Yield Increase

(Order-of Magnitude) 1 to 1.5 1 to 3

Time to Emplace Fracture (days) 1 to 4 0.5 to 1

Temporal Changes in 3 Decades of Hydraulic Emplacement

Performance

Conclusions:

• Hydraulic Fracturing Via DPT and Conventional Packer Methods

is becoming the most-widely accepted means of in-situ remediation

for Sites constrained by low permeability soils and elaborate

infrastructure.

• Hydraulic Fracturing and Enhanced Pressure Injections

significantly improves the distribution of remedial solutions and

contact time with contaminants, and accelerates the clean-up

period, dramatically reducing costs $$$.

• Advances in monitoring the distribution of hydraulic fractures and

viscous fluids has refined characterization of R.O.I and reduced the

need for physical confirmation.

Figure, Animation, and Photo Acknowledgements

John Fontana P.G.

Seth Hunt

Paul Willett

WebSite

Thank YouFor More Information Contact us at:

John V. Fontana P.G.

www.vistageoscience.com

Seth Hunt

www.foremostsolutions.com

Ron Bell, Geophysicists

www.IGSdenver.com

International Geophysical

Services LLC (HGI)

Methods & Advancements in Hydraulic Fracturing Technologies...

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