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SHALE PETROPHYSICAL CHARACTERISTICS Kashy Aminian Petroleum & Natural Gas Engineering West Virginia University INFUSE February 29, 2016
Transcript of Wvu shale gas mountain of excellenceunconventionalenergyresources.com/infuse/PDF-English...
SHALE PETROPHYSICAL CHARACTERISTICS
Kashy AminianPetroleum & Natural Gas EngineeringWest Virginia University
INFUSEFebruary 29, 2016
KEY RESERVOIR CHARACTERISTICS
Porosity
Permeability
The Reservoir Rock Contains a 3-D Network ofInterconnected Pores which allows for toStorage and Transmission of Fluids.
KEY RESERVOIR CHARACTERISTICS
THE OPEN SPACE CREATED BETWEENGRAINS DURING DEPOSITION IS REFERREDTO AS THE VOID, OR PORE, SPACE.
( )
p
b
b
p
V V
V Bulk Volume
V Pore Void Volume
φ =
=
=
KEY RESERVOIR CHARACTERISTICSPERMEABILITY IS DEFINED BASED ON AN EQUATION, DEVELOPEDBY HENRY DARCY:
( )1 2
q LkA p p
µ=
−
.
q Flow Rate through the Porous MediumA The Area across whic
Fluid Viscosith the flow occurs
L Length of the Mediumyµ
==
==
KEY RESERVOIR CHARACTERISTICS
( )1 2
kq LA p p
µ−
=
1 cp1 cc/sec
1 cm2
1 cm
1 darcy
1 atmOne darcy is a relatively high permeability and millidarcy(md) is commonly used as the permeability unit.
1 darcy = 1000 md
PERMEABILITY MEASUREMENT
Low Pressure High PressureGAS SLIPPAGE
UNCONVENTIONAL RESERVOIRS
SHALE GAS RESERVOIRS
GAS
STO
RAG
ECA
PACI
TY
PRESSURE
LANGMUIR ISOTHERM
=+L
SL
V pG
P pGs = Gas Storage CapacityVL = Langmuir Volume ConstantPL =Langmuir Pressure Constantp = Pressure, psia
MEASUREMENT OFSHALE PETROPHYSICAL PROPERTIES
PORE VOLUME
ADSORPTION
• Low-pressure gas pycnometry
• High-pressure mercury injection
• Low-temperature adsorption
• Gravimetric• Volumetric
• GRI Method• Pressure Pulse Decay
PERMEABILITY
PORE SIZE DISTRIBUTION• MICP• NMR• SEM/STEM• Low-temperature Adsorption
SHALE PERMEABILITY MEASUREMENT
• IT IS NOT PRACTICAL TO MEASURE THE PERMEABILITY OFSHALE BY CONVENTIONAL (STEADY-STATE) TECHNIQUESBECAUSE OF LOW PERMEABILITY.
• UNSTEADY-STATE METHODS
GRI METHOD (CRUSHED SAMPLE)
PRESSURE PULSE DECAY
CRUSHED SAMPLE PERMEABILITYDEVELOPED BY GAS RESEARCH INSTITUTE AND IS REFERRED TO AS "GRI" METHOD.
Particles in the 20-35 US mesh size range (0.85 to 0.5mm)
No Standard Protocol
Inconsistent Results
PRESSURE PLUS DECAY
DIFFERENT INTERPRETATIONS
COMPLEX AND TEDIOUS CALCULATIONS
CHALLENGES
• GAS SLIPPAGE CORRECTION
• IMPACT OF GAS ADSORPTION
• IMPACT OF STRESS
PRECISION PETROPHYSICAL
ANALYSIS LABORATORY (PPAL) AT WVU
MEASUREMENT CAPABILITIES
• PERMEABILITY (NANO-DARCY RANGE).• PORE VOLUME (0.1% ACCURACY).• ABSOLUTE PERMEABILITY (GAS PRESSURE CORRECTION)• IMPACT OF STRESS (RESERVOIR CONDITIONS).• IMPACT OF ADSORPTION
• PORE STRUCTURE CHARACTERIZATION
ACCURATE, CONSISTENT, AND REPEATABLE RESULTS
ABSOLUTE PERMEABILITY
Traditional Klinkenberg AnalysisGas Slippage Modified Klinkenberg Analysis
Gas Double Slippage
y = 90090x - 66.106R² = 0.9865
y = 57377x + 11.06R² = 0.9992
0
200
400
600
800
1000
0.0E+00 2.0E-03 4.0E-03 6.0E-03 8.0E-03 1.0E-02
Perm
eabi
lity,
nD
Inverse of Pressure, Psia-1
Helium
Nitrogen y = 8E+06x + 154.3R² = 0.9603
y = 5E+06x + 155.51R² = 0.9705
0
200
400
600
800
1000
0.0E+00 2.0E-05 4.0E-05 6.0E-05 8.0E-05 1.0E-04
Perm
eabi
lity,
nD
Inverse of Pressure Squared, Psia-2
ADSORPTION
ADSORPTION ISOTHERM
0
10
20
30
40
50
60
70
0 1000 2000 3000
Gs,
SFC
/ton
Pressure, psia
104 °F, TOC: 1.2% (Published Data)
79 °F, TOC: 0.8% (PPAL)
Crushed Sample (Commercial Lab)169 °F, TOC: 0.8%
IMPACT OF STRESS
( )1 3ok k
( )oln p p
SEQUENTIAL STRESS
90
110
130
150
170
190
210
230
250
500 2500 4500 6500 8500
Perm
eabi
lity,
nD
Net Stress, Psia
Series1Series2
90
140
190
240
290
340
500 2500 4500 6500 8500
Perm
eabi
lity,
nD
Net Stress, Psia
Series1Series2
0.7
0.8
0.9
1
0 0.5 1 1.5 2 2.5
Series1Series2Series 4
( )oln p p
ADSORPTION ISOTHERMS
Multilayer Adsorption
Slit-like poresNitrogen Adsorption at Low Temperature
Micromeritics ASAP 2020
