seismic attributes of the barnett and bakken shales
DESCRIPTION
Seismic attributes of the Barnett and Bakken shales. Bode Omoboya 16 th May, 2013. Introduction Bakken Shale Case Study Barnett Shale Case Study Other Forward Modeling Projects. Bakken Shale Quick Facts. VTI Anisotropy. Isotropic or HTI Anisotropy Due Open Vertical Fractures. - PowerPoint PPT PresentationTRANSCRIPT
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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) 200000Total Gas (tcf) 945Producable Gas (tcf) 20Depth (feet) 10000Thickness (feet) 150Pressure (psi) 5600Porosity (%) 5Matrix Permeability (nD)
10000
Pressure Gradient (psi/ft)
0.5
Clay Content (Middle Member %)
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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 400mMaximum Offset 2000mCMP Interval 20mDepth of Model 800m ( TWT to end of model =
350ms)Average Velocity of Model 5800m/sDominant 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 (h) Volume
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
10Water Saturated
Laboratory MeasuredGassmann Predicted
Stiff
ness
Coe
f-
ficie
nt (
GPa
)
C11 C33 C33 C44 C550
4
8
Glycerin SaturatedLaboratory MeasuredGassmann Predicted
Stiff
ness
Coe
f-
ficie
nt (
Gpa
)
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