Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
SEISMIC DATA
STATIC MODEL
DYNAMIC MODEL
Seismic Conditioned 3D Reservoir Modelling:
Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes
Offshore West Nile Delta
Egypt
Presented by
Richard D. Vaughan
RWE Dea Egypt
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Agenda
Modelling Objectives
Modelling Assumptions and Workflow
– Data Analysis
– Seismic Conditioned Reservoir Modelling Parameters
Parameters 3D Modelling as a E & P Risk Reduction tool
– Taurus Prospect Evaluation
– Libra Prospect Evaluation
– North Idku Slope Channel Evaluation
Conclusions
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Agenda
Modelling Objectives
Modelling Assumptions and Workflow
– Data Analysis
– Seismic Conditioned Reservoir Modelling Parameters
Parameters 3D Modelling as a E & P Risk Reduction tool
– Taurus Prospect Evaluation
– Libra Prospect Evaluation
– North Idku Slope Channel Evaluation
Conclusions
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Modelling Objectives
To create seismic conditioned 3D static modelling grids to assist with:
• 3D reservoir characterisation of slope canyon & channel turbidite systems
• Understand 3D distribution reservoir architecture and heterogeneity
• Pre-drill Independent assessment of GIIP
• Up-Scaling & Forward modelling
Well location optimisation
Minimum compartment size/well
Estimate Well deliverability
Evaluate various development plan strategies
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Inc
rea
sin
g s
inu
os
ity
Inc
rea
sin
g la
tera
l m
igra
tio
n
Inc
rea
sin
g w
idth
-de
pth
ra
tio
Co
nfi
ned
Un
co
nfi
ned
Increasing rate of sediment accumulation
Channel stacking patterns related to sinuosity, rate of sediment accumulation,
sand/mud ratio of sediment supplied (net to gross) and degree of channel confinement
After Pickering & Clark, 1998
What type of turbidite reservoir architecture are we exploring for and/or trying to develop?
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Overbank Shales
Channel sands Levee Heterolithics
Positive & negative amplitudes show
vertical – lateral stacking patterns
consistent with laterally offset stacked
submarine channel-levee deposits
“Negative Amp”
channels
Flooding Surface
Base Channel Complex
Taurus-1X
“Positive Amp”
channels
“East Taurus Complex”
“West Taurus Complex”
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Agenda
Modelling Objectives
Modelling Assumptions and Workflow
– Data Analysis
– Seismic Conditioned Reservoir Modelling Parameters
Parameters 3D Modelling as a E & P Risk Reduction tool
– Taurus Prospect Evaluation
– Libra Prospect Evaluation
– North Idku Slope Channel Evaluation
Conclusions
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Modelling Assumptions and Workflow
• The inherent 3D distribution of seismic amplitude and extracted attributes
can be interpreted geologically (seismic facies analysis)
• Meaningful relationship between data at the well scale (cm to metre-scale)
and seismic scale (12.5m x 25m bins)
• Calibration wells are correctly located within the grids
• Top depth converted map surface and internal model layers are
chronostratigraphically consistent
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
North Idku-4X Canyon Complex
25 Layer grid = 3D Model
3D volume
attribute (10ms
window) inserted
as 2D Trend
3D Grid: 25 x 25x (10msec) = c. 9.5m
Depth converted time
map 250msec below top
Depth Structure Maps
Artificial Base
Top
Chronostratigraphic Flooding surface
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Base Slope
Channel
Depth map
25242322212019181716151413121110987654321Top Taurus Slope Channel depth map
4 Km
Taurus-1X
Note: East and West Taurus
Slope channel complexes
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Proroportional grid of Route Mean Squared of Amplitude
Cell Size X = 12.5m & Y = 25m
Top grid surface
= layer 6
826 rows
(Y)25 layers
(Z)
1778Columns
(X)
2000 mTaurus-1X
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Data Analysis
• Derive relationship between seismic attributes at the well location and facies
types and petrophysical properties
• Condition and threshold attribute data with well data /rock type
• Generate facies, net:gross and porosity models (multiple realisations)
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Seismic Conditioned Reservoir
Modelling Parameters
• Facies Model
• Net:gross Model
• Porosity Model
• Gas expansion factor
• Water saturation
• GWC
Fixed -
seismic conditioned
by multiple realisations
Variable
(p10 – p50 – p90)
• Cap Press, Rel Perm, PVcomp – Data Conditioned
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
RMS Amplitude thresholds and Seismic facies types
Shale Hete
rolit
hic
Sand
Non Res Net reservoir
3000 4500
Data source: migrated 16 bit data
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
RMS amplitude threshold 1800-3000
RMS amplitude threshold 3000-4500
RMS amplitude threshold 4200-6000
Too little sand and heterolithic facies
Too much sand and heterolithic facies
Sand and heterolithic facies constrained at well location
Facies Model Realisations – Threshold Sensitivity
Column 890: oblique dip section
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Seismic Crossline 18825
Final Facies Model cross section
Taurus-1X
Taurus-1X
“East Taurus Complex”“West Taurus Complex”
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Interpolated Porosity
Interpolated
well porosities
Sand = 0.3
Heterolithic = 0.2
3D Model Parameters
Net to gross
Deterministic Porosity
Facies
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
500m range
3000m rangeFinal Stochastic Porosity Realisation
2000m range parallel
to channel belt orientation
Stochastic Porosity Realisations (controlled by variograms)
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Agenda
Modelling Objectives
Modelling Assumptions and Workflow
– Data Analysis
– Seismic Conditioned Reservoir Modelling Parameters
Parameters 3D Modelling as a E & P Risk Reduction tool
– Taurus Prospect Evaluation
– Libra Prospect Evaluation
– North Idku Slope Channel Evaluation
Conclusions
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
3D Modelling as a E & P Risk Reduction tool:
• Optimisation of exploration well locations
• Multiple scenarios for development/production well locations to assess
effective well drainage and deliverability
• Up-scaled models for forward dynamic simulation predictions
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Taurus Prospect Evaluation
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
1
2
3
4
5
A
Proximal levee-channel
Channel
sand
Proximal levee
heterolithics
Layer 5: Slice through a sinuous laterally and vertically
amalgamated channel complex
50metres
Can
yo
n F
ill–
sta
cked
ch
an
nel
levee
co
mp
lex
(pro
xim
al
–d
ista
l re
lati
on
sh
ips
reco
rde
db
y w
ell
pa
th)
300 metres
A A’
WELL
A’
Distal levee-
Overbank
Outcrop analogue
Bell Canyon Formation, West Texas
Well
Taurus-1X
From Kendrick, 2000
Post w
ell
Pre
dic
ted
Seis
mic
Fa
cie
s
H-p
ela
gic
slo
pe
DST – 1A
Pign
RMS Amp
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Max GWC 1980m TVDSS
DST–1A recorded rapid buildup due to lateral communication
between heterolithic levee-overbank thin beds with adjacent channel
N SW NES
Min GWC 1950m TVDSS
DST-1A
Taurus-1X
Channels connected to
Levees
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Libra Prospect Evaluation
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
1700m TVDss
2000m TVDss
1900m TVDss
GWC’s
Sensitivity
Libra Prospect canyon / channel complex – dip section
Confined canyon feeder
Ponded fan complex
Change in slope angle across faults
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Libra Prospect canyon / channel complex – strike section
1700m TVDss
2000m TVDss
1900m TVDss
GWC’s
Sensitivity
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
FaciesRMS Amp
Pre-drill facies predictions Well Libra-1X3D Model Layers
Dip section through 3D facies model
Strike section through 3D facies model
Libra-1X
Libra-1X
K- Libra
Canyon 3D
Reservoir model
Results
ELAN Interpretation
Post Drill
Adjustment
-12m Shift
6
7
8
9
10
11
12
13
14
GDT
GDT
Main Findings
• Model predicts
main pay interval
• Over-estimates
net-to-gross
Confined canyon feeder
Ponded fan complex
Libra-1x
Change
in slope
angle
across
fault
GDT
WUT
6
7
8
9
10
11
12
13
14
6
7
8
9
10
11
12
13
14
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
North Idku Slope Channel
Evaluation
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
NI-2x NI- 4x
Cut off in
gas-bearing
sequence
Cut off in
water-bearing
sequence
High RMS
amplitude
associated
with
gas-bearing
sequence
RMS
AMP
Seismic
Facies
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
North Idku LeaseWest Med
Deep Marine
North Alex.
Block B
North Abu Qir Dev. Lease
North Idku-4x
Discovery
North Idku
Lease
ARMADILLO
Prospect
North Idku-2X
Discovery
7.5 Km
2.5 Km
Depth Map
&
Static
Model(25m x 25m x c. 9.5m grid)
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Depth Map
&
Static
Model
North Idku-4x
N 2.5 km
Reservoir below
1511.5m TVDss
Reservoir above
GWC @ 1511.5m TVDss
North Alex B North Idku Concession
C.I =10m
1530
Seismic Facies“Sand”
>6000 RMS AMP
“Heterolithic”
>4500<6000
“Non-Reservoir”
<4500
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Simgrid: 100 x 100 x c. 9.5m
GWC
Projected
through model
Depth Map &
Simulation
Model
Connected volume
in red
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Dynamic Simulation Model with 4 “Virtual” wells and a discovery well
Well V1Well V2
GWC @ 1511.5m TVDss
based on NI-4x results
Initial Gas Saturation
Well V3
Well NI - 4x
discovery
Initial Gas Saturation
Armadillo
Viper Canyon
Including NI-4x
NI-2x
Dynamic Simulation
Model
400m
Well V4
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Up-scaled
simulation modelProduced Gas over 25 years
Cell Size
100 x 100 x 9.5m
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Agenda
Modelling Objectives
Modelling Assumptions and Workflow
– Data Analysis
– Seismic Conditioned Reservoir Modelling Parameters
Parameters 3D Modelling as a E & P Risk Reduction tool
– Taurus Prospect Evaluation
– Libra Prospect Evaluation
– North Idku Slope Channel Evaluation
Conclusions
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Conclusions
• Static models allow visualisation of reservoir complexity
(architecture & heterogeneity – connected / drainable volumes)
• Multiple realisations can be modelled rapidly, testing sensitivities
to different rock and fluid parameters
• Independent check of GIIP
• Dynamic simulation studies
• Various development plans can be evaluated
Seismic Conditioned 3D Reservoir Modelling: Examples from Gas-Bearing Pliocene Slope
Channel/Canyon Complexes, Offshore Nile Delta, Egypt
27-28 April 2003
Acknowledgements
The author would like to thank RWE Dea, bp Egypt and EGAS
for permission to present this material
EGAS