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1. Shale & Tight Reservoir Simulation
Jim Erdle - VP/USA & LA
OCTOBER 2012

2. AGENDA
How CMG’s simulators are being used
oShale/Tight reservoir modelling features
oShale/Tight reservoir modelling workflows
How other simulators are being used
Shale Operators using CMG’s simulators
SPE References

3. CMG’S PRODUCTS
IMEX – Black Oil reservoir simulator
GEM – EOS-compositional reservoir simulator
STARS – Thermal/Reactive-Transport reservoir simulator
GEOMECH – Geomechanics simulator (GEM & STARS)
BUILDER – Model creation/editing GUI
RESULTS – Simulator output display GUI
WINPROP – PVT modelling
CMOST – SA, UA, Aided History-Matching & Optimization

4. MODELLING FEATURES
PVT
oBlack Oil treatment (IMEX)
primary production of dry gas, wet gas, black oil, volatile oil and gas condensate reservoir fluids
oMulti-component EOS Treatment (GEM)
Adds ability to model Multi-Component fluids including non-HC gases (e.g. CO2, H2S, acid gas, Flue Gas & N2) for EOR

5. MODELLING FEATURES
Single vs Dual Porosity
oSingle Porosity if no open natural fractures
oDual Permeability if open natural fractures

6. MODELLING FEATURES
Adsorped Components
oSingle gas component (new in IMEX for 2012)
oMultiple gas or oil components (GEM)

7. MODELLING FEATURES
Diffusion
oMulti-component molecular diffusion (GEM)
Competitive with darcy flow in some very low matrix perm situations
Injection of solvents to aid liquid recovery (e.g. CO2, propane, etc.)
Sequestration of CO2, acid gas, etc.

8. MODELLING FEATURES
Relative Perm & Capillary Pressure
oIndependent curves for matrix, natural fractures & propped fractures
Usually straight line for natural & propped fracs
Matrix can be oil-wet or water-wet (which is it?)
Can include hysteresis if modelling solvent injection
Can also include wettability alteration via relative permeability interpolation (new in GEM for 2012)

9. MODELLING FEATURES
Compaction/Dilation
oPressure-dependent Compaction/Dilation tables for modelling degradation of permeability & porosity
In propped fractures, natural fractures & matrix, including hysteresis for modelling shut-in periods
oEffective Stress-dependent Compaction/Dilation tables when using GEOMECH (GEM)
Barton-Bandis approach for modelling of natural fracture perm vs Effective Stress

10. MODELLING FEATURES
 Compaction/Dilation
Unpropped Fracture
Compaction Table
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
1000 1500 2000 2500 3000 3500 4000
Pressure (psi)
Conductivity Multiplier
Propped Fracture
Compaction Table
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
1000 1500 2000 2500 3000 3500 4000
Pressure (psi)
Conductivity Multiplier

11. MODELLING FEATURES
Initial Fluid Saturations
oNon-equilibrium initialization of fluids for modelling presence and flowback of frac fluids in propped & natural fractures

12. MODELLING FEATURES
Explicit Gridding of Propped Fractures
oLS-LR-DK (TARTAN) grids to model propped fracs
oSingle Plane or Complex geometry
oNon-Darcy flow in propped fracs

13. MODELLING FEATURES
Explicit Gridding of Propped Fractures
Single Plane geometry
Complex geometry

14. MODELLING FEATURES
Explicit Gridding of Propped Fractures
oAutomatic generation of TARTAN grids (BUILDER)
oSRV delineation (BUILDER)
Import & Filtering of Micro Seismic data
Interactive selection on simulation grid display
oTARTAN grids can be applied to any parent grid geometry
Cartesian & Corner Point Grids

15. MODELLING FEATURES
Explicit Gridding of Propped Fractures
Hydraulic Fracture Wizard
Microseismic Wizard

16. MODELLING FEATURES
Time-dependent Propped Fractures
oTARTAN grids can be added when wells are fracked
Don’t have to put all grids in place at beginning of run!
Efficient way to model re-fracs & multi-well models
oCompaction/Dilation Tables (with Hysteresis) can be time-dependent (coming in Dec 2012)

17. MODELLING WORKFLOW
2.Build single well base models
5.Build multi-well models
3.Perform SA & AHM on single well models
4.Forecast EUR for single well models
6.Perform OPT of multi-well models
1.Choose CMG simulator with required physics

18. Base Case Results
Initial model with assumed values does not match historical production data
oToo much gas produced
oNot enough water produced

19. Sensitivity Analysis using CMOST
Reservoir parameter uncertainty
oFracture Permeability
oFracture Width
oPressure Dependent Permeability of Fracture (CROCKTAB)
oLangmuir Adsorption parameters
oDiffusivity
oInitial Water Saturation in Fractures (to model water from the HF fluid)

20. Sensitivity Analysis using CMOST

21. History Match Error Reduction
 Objective Function Error Reduced from 55% to 1.4%
21

22. History Match – Final Results

23. History Match – Final Results
History match error reduction
oOverall HM error reduced from 55% to 1.4%
oFinal Gas Rate Match error = 0.70%
oFinal Water Rate Match error = 2.13%
Total Calendar Time to complete HM
oEngineering Time = 10 hours
oComputing Time = 15 hours (8 concurrent 2-way parallel jobs)
oTotal calendar time = 25 hours

24. ANOTHER APPROACH TO GRIDDING
 Representation of Single-Plane Propped Fractures
o Some are using Logarithmically Refined grids over entire model in
both X & Y directions (LS-GR-DK grids) to model single-plane fracs
Mangum
0 100 200 300 400 500 600 700 800 900 1,000 1,100 1,200 1,300 1,400 1,500
0 100 200 300 400 500 600 700 800 900 1,000 1,100 1,200 1,300 1,400 1,500
100 0 -100 -200 -300 -400 -500 -600 -700 -800 -900
-800 -700 -600 -500 -400 -300 -200 -100 0 100 200
0.00 180.00 360.00 feet
0.00 55.00 110.00 meters
File: ECLIPSE_Global Grid Refinement.dat
User: kpatel
Date: 7/27/12
Scale: 1:2374
Y/X: 1.00:1
Axis Units: ft
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
Porosity 2011-07-24 K layer: 1
Mangum
-100 0 100 200 300 400 500 600 700 800 900 1,000 1,100 1,200 1,300 1,400 1,500
-100 0 100 200 300 400 500 600 700 800 900 1,000 1,100 1,200 1,300 1,400 1,500
200 100 0 -100 -200 -300 -400 -500 -600 -700 -800 -900
-900 -800 -700 -600 -500 -400 -300 -200 -100 0 200
0.00 195.00 390.00 feet
0.00 60.00 120.00 meters
File: CMG_Local Grid Refinement.dat
User: kpatel
Date: 7/27/12
Scale: 1:2480
Y/X: 1.00:1
Axis Units: ft
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
Porosity 2011-07-24 K layer: 1
Global Logarithmic Grids CMG’s TARTAN Grids

25. ANOTHER APPROACH TO GRIDDING
TARTAN grids = Same Results in 1/10 the time!

26. ANOTHER APPROACH TO GRIDDING
TARTAN grids = Same Results in 1/10 the time!

27. ANOTHER APPROACH TO GRIDDING
 TARTAN grids = Same Results in 1/10 the time!
0
1000
2000
3000
4000
5000
6000
0 2000 4000 6000 8000 10000 12000
Pressure
Time
Mangum
400 500 600 700 800 900 1,000
400 500 600 700 800 900 1,000
-200 -300 -400 -500 -600
-600 -500 -400 -300 -200
0.00 75.00 150.00 feet
0.00 25.00 50.00 meters
File: cmg_local grid refinement.irf
User: kpatel
Date: 7/27/12
Scale: 1:1148
Y/X: 1.00:1
Axis Units: ft
791
1,193
1,596
1,998
2,401
2,803
3,205
3,608
4,010
4,413
4,815
Pressure (psi) 2039-11-24 K layer: 1
Pressure 40 ft from propped frac is the same!

28. USING CMG FOR SHALE/TIGHT RESERVOIRS
•Anadarko
•Apache
•BG Group
•BHP Billiton
•BP
•Chesapeake
•Chevron
•Devon
•Encana
•EOG
•ExxonMobil
•Marathon
•Matador
•Noble Energy
•Reliance
•Rosetta Resources
•Samson
•Shell
•Statoil
•Talisman
•Total
•Venoco
•Vitruvian
•XTO

29. SPE REFERENCES
CSUG/SPE 148710-PP “Shale Gas Modeling Workflow: From Microseismic to Simulation – A Horn River Case Study”
oJoint paper with CMG and NEXEN
IPTC-14940 “Evaluation in Data Rich Fayatteville Shale Gas Plays – Integrating Physics-based Reservoir Simulations with Data Driven Approaches for Uncertainty Reduction”
oby Yitian Xiao et al (ExxonMobil) presented at 2012 IPTC Bangkok

30. SPE REFERENCES
SPE 147596 “Shale Oil Production Performance from a Stimulated Reservoir Volume”
oby A.S. Chaudhary, C. Economides & R. Wattenbarger (TAMU) presented at 2011 ATCE - Denver
SPE 146975 “Heat Transfer Applications for the Stimulated Reservoir Volume”
oby S. Thoram & C. Economides (TAMU) presented at 2011 ATCE - Denver

31. SPE REFERENCES
SPE 132093 “Accurate Simulation of Non-Darcy Flow in Stimulated Fractured Shale Gas Reservoirs”
oby B. Rubin (CMG) presented at 2010 WRM – Anahiem

32. Thank you!
Any Questions?