bode omoboya 16 th may, 2013 1 introduction bakken shale case study barnett shale case study ...
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Bode Omoboya
16th May, 2013
Seismic attributes of the Barnett and Bakken shales
Introduction
Bakken Shale Case Study
Barnett Shale Case Study
Other Forward Modeling Projects
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VTI Anisotropy
Isotropic or HTI AnisotropyDue Open
Vertical Fractures
VTI Anisotropy
Geologic Age Upper Devonian/Lower Miss
Lithology (Middle Member)
Sandstone/Siltstone/Dolomite
Total Area (sq mi) 200000
Total Gas (tcf) 945
Producable Gas (tcf) 20
Depth (feet) 10000
Thickness (feet) 150
Pressure (psi) 5600
Porosity (%) 5
Matrix Permeability (nD)
10000
Pressure Gradient (psi/ft)
0.5
Clay Content (Middle Member %)
5
Average Horz Well Cost ($M)
5.5Most oil in the Bakken petroleum system resides in open fractures in the Middle Member (Pitman et al, 2001). Source: USGS
Bakken Shale Quick Facts
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MD= 9100 ft
MD= 9250 ft
Well: NELSON
Upper Shale
Middle Member
Lower Shale
Core Image from NDIC
Bakken Shale – Core Samples and Well Logs
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𝐼𝐺𝑅=𝐺𝑅 𝑙𝑜𝑔−𝐺𝑅𝑚𝑖𝑛
𝐺𝑅𝑚𝑎𝑥−𝐺𝑅𝑚𝑖𝑛
1000 ft. Interval40% – 60% Vsh
200 ft. Interval80% Vsh
𝑉 h𝑠 =𝐼𝐺𝑅
3−2 𝐼𝐺𝑅
Steiber, 1970
Bakken Shale – Shale Volume
Data Courtesy of Hess Corporation
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X/D=14500ft (offset)
V=3000ft/s
V=16000ft/s
t=700 ms
t=1800 ms X= 0 ft X= 15000
ft
Bakken Shale – Non-Hyperbolic Moveout
C11 C33 C44 C66 C13 e g d
343 227 54 106 107 0.255 0.481 -0.051
from Core = 0.341
from Seismic ≈ 0.32
Jones and Wang, 1981
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Bakken Shale – Forward Modeling Project
Physical modeling of anisotropic domains: Ultrasonic imaging of laser-etched fractures in glass(Geophysics, 2013 )Robert. R. StewartNikolay DyaurBode OmoboyaJ.J.S de FigueiredoMark WillisSamik Sil
Before Post-stack Migration
After Post-stack Migration
Model C1
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Minimum Offset 400m
Maximum Offset 2000m
CMP Interval 20m
Depth of Model 800m ( TWT to end of model = 350ms)
Average Velocity of Model 5800m/s
Dominant Frequency/ Wavelength
120 Hz / 50m
Model C3
Model C10
Model C9“BAKKEN MODEL”
Schematic of NMO eta scan experiments on glass models
Bakken Shale – Forward Modeling Project
Model C3Max = 0.0𝞰Blank Model
Model C10Max = 0.23𝞰VTI Model
Model C9 Azimuth 0Max = 0.14𝞰VTI+HTI+VTI
Model C9 Azimuth 45Max = 0.08𝞰VTI+HTI+VTI
Model C9 Azimuth 90Max = -0.06𝞰VTI+HTI+VTI
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5
-0.1
-0.05
0
0.05
0.1
0.15
0.2
0.25
Max 𝞰𝞰
Model C3Blank Model
Model C10VTI Model
Model C9Azimuth 0
Model C9Azimuth 45
Model C9Azimuth 90
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𝞰= -0.3
𝞰= 0.3
𝞰= -0.3
𝞰= 0.3
t = 350 ms
t = 350 ms
t = 350 ms
t = 350 ms
t = 350 ms
Bakken Shale – Forward Modeling Project
Barnett Shale Quick Facts
N-S structural cross section through the Newark Field in the Fort Worth Basin. Modified after Burna and Smosna, 2011
Geologic Age Mississipian
Lithology Dense Organic rich shale
Water Saturation((clay-bound)
20-30%
Gas Saturation 70-80%
Depth (feet) 4000 - 5000
Thickness (feet) 5-1000 ft
Pressure (psi) 5600
Porosity (%) 5
Natural fractures 100 to 120 deg
Natural fractures More common in limestone interbeds
Artificial fractures Oriented in the direction of minimal stress
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Barnett Shale – Top Ellenberger – Maximum Curvature Attribute
Well XWell Y
Data Courtesy of Marathon Oil
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Barnett Shale – CDP Gathers after Time Processing and Migration
Barnett Shale – Migrated Stack + FXY Decon
t = 0s
t = 1.5s
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Barnett Shale – Residual eta ( ) hVolume
t = 0s
t = 1.5s
h = -0.2
h = 0.2
Barnett Shale – Seismic to well tie
Well Y
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P-Impedance Volumet = 0.55ms
t = 0.85ms
Base Marble Falls
Top Barnett
Top Ellenberger
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Density Volumet = 0.55ms
t = 0.85ms
Base Marble Falls
Top Barnett
Top Ellenberger
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Mu-Rho Volumet = 0.55ms
t = 0.85ms
Base Marble Falls
Top Barnett
Top Ellenberger
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Barnett Shale – Forward Modeling Project
Constituent Materials:
• Resin• Plexiglass
(polycarbonate)• Copper tubes
Experimental study of the influence of fluids on seismic azimuthal anisotropy.(Geophysical Prospecting, 2013, submitted, under review)Bode OmoboyaEmrah PacalJ.J.S de FigueiredoNikolay DyaurRobert. R. Stewart
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Barnett Shale – Forward Modeling Project
Vs
(Z)
m/s
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C11 C33 C33 C44 C550
5
10
Water SaturatedLaboratory MeasuredGassmann Predicted
Sti
ffn
ess C
oef-
ficie
nt
(GP
a)
C11 C33 C33 C44 C550
4
8
Glycerin Saturated
Laboratory MeasuredGassmann Predicted
Sti
ffn
ess C
oef-
ficie
nt
(Gp
a)
C11 C33 C13 C44 C55
C11 C33 C13 C44 C55
Barnett Shale – Forward Modeling Project
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Model M2Crack Density = 4.5 %
Model M3Crack Density = 4.0 %
Model M1Reference Model
Hudson, 1981
ɛ =
Shear wave anisotropy from aligned inclusions: ultrasonic frequency dependence of velocity and attenuation(Geophysical Journal International, 2013)J.J.S de FigueiredoNikolay DyaurBode OmoboyaRobert. R. Stewart
Forward Modeling Examples: Source Frequency VS Anisotropy
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Forward Modeling Examples: Source Frequency VS Anisotropy
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Forward Modeling Examples: Source Frequency VS Anisotropy
ϒ=12 (𝑉 𝑠1
2
𝑉 𝑠22 − 1 )
Thomsen, 1986
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Dr. Steve Peterson – Marathon OilMichelle Simon – Hess CorporationDr. Edip Baysal – Paradigm Schlumberger (For VISTA Processing
Software)
Acknowledgement