1. Reservoir Engineering Aspects of Unconventional Reservoirs
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom BLASINGAME
Department of Petroleum Engineering
Texas A&M University
College Station, TX (USA)
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011) 1

2. Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs Brief Biography — Tom Blasingame
Tom BLASINGAME
Department of Petroleum Engineering
Texas A&M University
College Station, TX (USA) —
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011) 2

3. Short Bio: Blasingame Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

4. Reservoir Engineering Aspects of Unconventional Reservoirs Start-Up
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs Start-Up
Tom BLASINGAME
Department of Petroleum Engineering
Texas A&M University
College Station, TX (USA) —
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011) 4

5. Start-Up: Unconventional Reservoir Systems are DIFFERENT
Flow mechanisms (…nano-scale flow mechanisms)
Fluids are often at critical state (…uniqueness? cause?)
Overpressure is good (…stresses are poorly understood)
Clean-up phase must be managed (…no "choke cowboys")
Shales are generally dessicated (…low water recovery)
Fracture patterns poorly understood (…rock mechanics)
Hydrocarbon liquid production (…artificial lift)
Simultaneous Exploration/Development (…fast track)
"Completions can't Trump Geology" (…but we try)
Unconventional Plays are "Statistical" (…lots of wells)
Stimulation → Multi-Fracture Horizontal Wells (…future?)
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

6. Reservoir Engineering Aspects of Unconventional Reservoirs Overview
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs Overview
Tom BLASINGAME
Department of Petroleum Engineering
Texas A&M University
College Station, TX (USA) —
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011) 6

7. Nano-Scale Flow Behavior
Overview:
Orientation
Nano-Scale Flow Behavior
Time-Rate Analysis: (aka Decline Curve Analysis)
Time-Rate-Pressure Analysis: (aka Production Analysis)
Practical Aspects
Challenge Points for Unconventional Reservoirs
Questions/Discussions
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

8. Reservoir Engineering Aspects of Unconventional Reservoirs Orientation
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs Orientation
Tom BLASINGAME
Department of Petroleum Engineering
Texas A&M University
College Station, TX (USA) —
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011) 8

9. Orientation: Reservoir Engineering Aspects of UR
Where we want to be: (or so we think)
Fit for purpose stimulation (... oil/gas/condensate/geology)
Effective reservoir monitoring (... this is important!)
Early EUR (months? years?) (... prediction/correlation)
Minimum Well Spacing (... geology + PVT + modeling(?))
How do we get there…
Better understanding of flowback/dewatering (... optimization)
Pressure-dependent properties… (... k, FcD, desorption?)
Understanding of the pore-scale (... what flows/when/how)
Petrophysics (... conventional petrophysics not adequate)
PVT (... oil/gas/condensate/water — HP/HT)
Facts of life…
Analogs (... need to understand uncertainty (very high))
EUR (... minimum of months for high confidence)
IP (... may be uncorrelated with EUR)
Early Productivity (... poor wells don't get better)
Time-Rate Analysis (... not representative? (chaotic operations))
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

10. Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs How Small is Small? (nano-scale pores)
Tom BLASINGAME
Department of Petroleum Engineering
Texas A&M University
College Station, TX (USA) —
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011) 10

11. Pore-Scale: Nelson Pore/Molecule Size Chart
Question(s):
How small are pores in shale gas? Note that the size of the pores is on the order of 5-10 times the size of the fluid molecule.
AAPG Bulletin, v. 93, no. 3 (March 2009) Pore-throat Sizes In Sandstones, Tight Sandstones, and Shales P.H. Nelson, USGS
Perspective:
The concept of pores and pore throats begins to break down at these scales.
The flow path can be as small as molecular diameters (or less).
Issues:
How do the fluids move?
Darcy flow?
Dispersion (gases)?
Knudsen flow?
How are the fluids stored?
In the organic matter?
Adsorbed?
Another mechanism?
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

12. Pore-Scale: Shale Pore Space (Barnett Example)
Question(s):
Where is/are the gas/liquid stored? There is porosity, often in the organic materials.
Why is the phase behavior of many shales "near critical"? Nanopores?
J. Sedimentary Research, v. 79/12 (2009) Morphology, Genesis, and Distribution of Nanometer-scale Pores in Siliceous Mudstones of the Mississippian Barnett Shale Loucks, R.G., R.M. Reed, S.C. Ruppel, and D.M. Jarvie
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

13. Pore-Scale: Petrophysics/Permeabilityvx vy
Gas Flow
SPE Improved Permeability-Prediction Relations for in Low Permeability Sands F.A. Florence, Occidental Petroleum Corp., J.A. Rushing, Anadarko Petroleum Corp., K.E. Newsham, Apache Corp., and T.A. Blasingame, Texas A&M U.
a. Gas Slippage — Kundt, A. and Warburg, E.: "Über Reibung und Wärmeleitung verdünnter Gase, " Poggendorfs Annalen der Physik und Che-mie (1875), 155, 337.
b. Knudsen "microflow" model (Modified from Karniadakis and Beskok, 2002).
c. Microflow model and correlation, "fully implicit" formulation.
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

14. Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs Time-Rate Analysis
Tom BLASINGAME
Department of Petroleum Engineering
Texas A&M University
College Station, TX (USA) —
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011) 14

15. Time-Rate: Schematic Production Performance Plot
Logarithm of Rate
Production Time
Hyperbolic Rate
Exponential Rate
"Switch Point" from Hyperbolic to Exponential
Economic Limit (in rate — qlimit)
= Estimated Ultimate Recovery (EUR) [The area under the hybrid (hyperbolic- exponential rate curves]
Economic Limit (in time — tlimit)
(tlimit)
(qlimit)
Discussion: Schematic Production Performance Plot
The schematic represents the most common approach to EUR.
Used CAREFULLY, this should be valid (other methods needed).
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

16. Time-Rate: Flow Regimes — Multi-Fracture Horizontal Well
Discussion:
Very high permeability case (30 md?) → blame graduate student.
Exhibits various flow regimes.
Note square-root time approximation … poor man's EUR (too high).
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

17. Time-Rate: Flow Regimes — Multi-Fracture Horizontal Well
1:2 Slope (high FcD)
Formation Linear Flow Regime
Compound Linear Flow Regime
1:4 Slope (low FcD)
Elliptical
Flow Regime
Logarithm of Production Rate
Bilinear Flow
Regime
Transition
Regime
Early-Time Regimes are HYPERBOLIC?
1:1 Slope Depletion (SRV?)
Logarithm of Production Time
Discussion:
1:2 Slope → b=2 (HIGH fracture conductivity) .
1:4 Slope → b=4 (LOW fracture conductivity).
This is a schematic, it overly simplifies the system.
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

18. Time-Rate: Modified Hyperbolic Rate Relation
Decline Function: D(t)
Hyperbolic Function: b(t)
b Function: b(t)
b(t)
Logarithm of Production Rate, q(t)
b(t) ≈ 2
Logarithm of D(t) and b(t)
q(t)
1:2 slope
D(t)
Logarithm of Production Time
Discussion:
qDb functions are DIAGNOSTIC.
D(t), b(t), and b(t) are evaluated continuously (at all points).
This shale gas case exhibits b=2 behavior → q = a√t (Linear Flow).
Appears to be "hyperbolic," but this is just the Linear Flow portion.
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

19. Time-Rate: Power-Law Exponential Rate Relation
PLE Rate Relation:
Decline Function: D(t)
Hyperbolic Function: b(t)
b Function: b(t)
Logarithm of Production Time
Logarithm of D(t) and b(t)
q(t)
D(t)
b(t)
Logarithm of Production Rate, q(t)
Discussion:
qDb functions are DIAGNOSTIC.
Power-law exponential relation is derived from:
No direct analog to hyperbolic case.
This is a "tight gas" reservoir case.
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

20. Time-Rate: Continuous EUR
[hyperbolic]
[PLE]
[qg(t) vs. Gp(t)]
c. CEUR governing equations.
a. Continuous EUR (CEUR) process plots.
b. CEUR hyperbolic, PLE, and q-Gp summary plots.
d. CEUR master summary plot (all results).
From: SPE (2009) Continuous Estimation of Ultimate Recovery, S. Currie, D. Ilk, and T. Blasingame, Texas A&M U.
Discussion:
EUR is computed at each "time step" (cumulative or incremental).
EUR estimated for each model.
EUR comparison plots probably min/max trends.
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

21. Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs Time-Rate-Pressure Analysis
Tom BLASINGAME
Department of Petroleum Engineering
Texas A&M University
College Station, TX (USA) —
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011) 21

22. Time-Rate-Pressure: Flowing Material Balance Plot
Question(s):
What is the "Flowing Material Balance" plot? In simple terms, pwf(t) data are "converted" to pavg(t) data using the pseudosteady-state flow equation, then plotted as a straight-line extrapolation function and "solved" for gas-in-place.
JCPT (June 1997), The 'Flowing' Gas Material Balance L. Mattar and R. McNeil, Fekete Assoc.
"Flowing Material Balance" Plot:
Theory:
Palacio and Blasingame [1993]
Mattar and McNeil [1997]
Agarwal et al [1999]
Advantages:
Straightforward and intuitive.
Shut-in pressures NOT required.
Direct estimation of contacted gas-in-place.
Limitations:
Boundary-dominated flow regime must exist.
a. The "Flowing Material Balance" (Normalized Rate-Cumula-tive Function Plot) formulation is derived using the solution for the diffusivity equation during boundary-dominated flow regime. This formulation provides a direct estimate of the contacted gas-in-place using time, flowing wellbore pres-sure, and flowrate data.
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

23. Time-Rate-Pressure: Material Balance Time
Question(s):
Can the well-reservoir model be inferred from such data? Yes.
Is diagnosis sufficient? No, we must also be able to model/history match data with a model (complete process).
SPE (1993) Decline Curve Analysis Using Type Curves — Analysis of Gas Well Production Data J.C. Palacio and T. Blasingame, Texas A&M U.
Transient
Flow
Boundary-Dominated
Flow
a. Raw (daily) rate and pressure data — bottomhole pressures are calculated, note the effect of liquid loading.
b. "Transformed" data shows fractured well response at early times, very strong evidence of closed system at late times.
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

24. Time-Rate-Pressure: Flowback Analysis
SPE A Comprehensive Workflow for Early Analysis and Interpretation of Flowback Data from Wells in Tight Gas/Shale Reservoir Systems D. Ilk and S.M. Currie, Texas A&M U., D. Symmons, Consultant, J.A. Rushing, Anadarko Petroleum, N.J. Broussard, El Paso, and T.A. Blasingame, Texas A&M U.
a. Crossplot — All wells: qg versus qw.
c. Crossplot — All wells: Dp2/qg versus t.
b. Crossplot — All wells: pcf versus t.
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)
[DI]

25. Time-Rate-Pressure: Time-Rate Diagnostics
SPE Hybrid Rate-Decline Models for the Analysis of Production Performance in Unconventional Reservoirs D. Ilk and S.M. Currie, Texas A&M U., D. Symmons, Consultant, J.A. Rushing, Apache, and T.A. Blasingame, Texas A&M U.
a. b-derivative — Holly Branch Wells.
b. b-derivative — "Shale Gas Field C" Wells.
c. b-derivative — All Models (Holly Branch Well).
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)
[DI]

26. Time-Rate-Pressure: Integration of Results
SPE (2011) Integration of Production Analysis and Rate-time Analysis via Parametric Correlations — Theoretical Considerations and Practical Applications D. Ilk, DeGolyer and MacNaughton, J.A. Rushing, Apache, and T.A. Blasingame, Texas A&M U.
Horizontal well with multiple vertical fractures:
"Shale Gas Field C"
a. Correlation plot — kcal versus kmeas.
Power-Law Exponential Relations:
"Shale Gas Field C"
b. Correlation plot — EURcal versus EURmeas.
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

27. Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs Practical Aspects
Tom BLASINGAME
Department of Petroleum Engineering
Texas A&M University
College Station, TX (USA) —
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011) 27

28. Practical Aspects: Stimulation
"You only produce from what you frac …" Anonymous
Individual Fractures from Individual Perforation Clusters
Complex Fractures from Individual Perforation Clusters
Project Rulison (1971) Stimulation using Atomic Weapons
Discussion:
Maximizing SRV (Stimulated Reservoir Volume)
Build Complexity → Slickwater
Build Conductivity → Hybrid/Gel Systems
Future Stimulation Challenges:
Can we "rubblize" the reservoir?
Can we "pulverize" the reservoir?
Can we do this with little or no water?
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

29. Practical Aspects: Clean-Up
100
101
10-5
102
103
10-4
10-3
Total Fluid Material Balance Time, days
Total Fluid Productivity Index, STB/D/psi
1:2 slope
Formation Linear Flow
(very high fracture
conductivity)
Clean-up
Behavior
Discussion:
Build choke profile slowly (2/64ths every 2-3 days).
Hold choke constant once rates peak.
For HPHT systems, start at 10-12/64ths, build to ths.
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

30. Practical Aspects: Pressure Transient Analysis
Dimensionless Time
Dimensionless Pressure
Nearby well
is being stimulated.
1:4 Slope
Nearby well
is being stimulated.
Apparent 1:4 slope for pressure drop and
pressure drop derivative functions
 LOW CONDUCTIVITY VERTICAL FRACTURES.
Discussion:
Multiple BHP pressure transient test data sets (5 wells).
Apparent 1:4 slope → low conductivity vertical fractures.
Data are "normalized" (dimensionless) in pressure drop and time.
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

31. Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs Challenge Points for Unconventional Reservoirs
Tom BLASINGAME
Department of Petroleum Engineering
Texas A&M University
College Station, TX (USA) —
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011) 31

32. Challenge Points: "What Keeps Me Up at Night…"
What we REALLY know…
Tight gas is relatively easy (... vertical wells, HP/HT, PVT)
Gas shales are technically viable as a resource (… economics?)
Horizontal multi-fractured wells (… (now) taken for granted)
What we THINK know…
The fracture geometry is (... planar? complex? who cares?)
The phase behavior (… can be extremely complex)
The ptf to pwf conversion(s) (... early-time heavy water load?)
What we may NEVER know…
Distribution of natural fractures (... impossible?)
Transport of gas/liquids in shales (... via organic matter?)
What we SHOULD KNOW in the near future…
Duration of data required for EUR (... more is always better)
Better understanding of phase behavior (... not "conventional")
Optimal well spacing/orientation/placement (... do this early!)
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

33. Challenge Points: "Conventional Wisdom…"
Estimated Ultimate Recovery (EUR)?
Early EUR? (... can this be meaningful?)
EUR = f(t)? (... how do we incorporate this?)
Well Spacing? (... is this really the holy grail?)
QUANTIFYING reservoir properties?
Pressure Transient Analysis (... ultra-low k ... issues?)
Production Analysis (... ptf may not be sufficient)
Petrophysical analysis (... theory ≠ application)
Liquids-Rich Systems?
Fluid-Flow Mechanisms (... what is really flowing where?)
PVT (... near-critical fluids are not trivial)
Improved Recovery (... we all know this is coming)
Fit-for-Purpose Stimulation (... higher FcD, more complexity)
Artificial Lift (... fact of life)
Recovery (... low to extremely low primary recovery?)
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

34. Challenge Points: "Everybody Has An Opinion"
Never-Ending Arguments…
SRV (... what is it, really?)
Desorption (... significance? timing? relevance?)
Stimulation Fluids (... where does it go? does it matter?)
Microseismic (... crystal ball, roulette wheel, or roadmap?)
Pressure-Dependent Whatever (... so what?)
Natural Fractures (... if/when/why/what?)
Dual Porosity/Dual Permeability (... what about the physics?)
Well Placement/Effect of Layering (... when does it matter?)
Things that SHOULD help…
Production Logs (... but just a snapshot in time)
Optimal Proppant Design/Placement (... obvious, but)
Stimulation Stages/Perforation Clusters (... geology + logs)
Things that DEFINITELY WOULD help…
Measured pwf (... yes, this is my favorite song)
Downhole Fluid Sampling (... sooner or later)
Horizontal Core (... why not?)
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

35. Challenge Points: "My Crystal Ball Tells Me…"
EUR:
Time-Rate Analyses (... may not be sufficient)
Time-Rate-Pressure Analyses (... requires reservoir model)
Constraints (... e.g., 15 years seems reasonable)
Reservoir Modeling: (i.e., simulators)
Present (... conventional models with modifications)
Near-Future (... fundamental flow kinetics, complex geometries)
Distant-Future (... pore-scale phenomena, nano-scale PVT, ?)
Reservoir Engineering Tools:
Material Balance Methods (... not applicable at reservoir-scale)
Pressure Transient Tests (... surprisingly good in cases [need k])
Production Analysis (... very good in cases [need good ptf data])
Reservoir Fluids (... very complex, near-critical liquids)
EOR (... not sure where to start — CO2, lean gas, ???)
Ad-hoc Tools (... e.g., Linear flow analysis — lack resolution)
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011)

36. Reservoir Engineering Aspects of Unconventional Reservoirs
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
End of Presentation
Tom BLASINGAME
Department of Petroleum Engineering
Texas A&M University
College Station, TX (USA)
Presentation at SPE GCS Reservoir Study Group
Houston, TX (USA) — 27 October 2011
Reservoir Engineering Aspects of Unconventional Reservoirs
Tom Blasingame — Texas A&M University (27 October 2011) 36