High Resolution Carbonate Reef Interpretation Using Cross Well Data

Thomas Morgan, Ph.D., SchlumbergerMike Raines*, Whiting Petroleum*formerly with Sandridge Energy

Sites:Michigan

West Texas

Focus:Gross Structure

Internal Structure

Depositional Environments

Geological Information

Well Logs

Geophysical Data

Geological Interpretation

Michigan Silurian Reef

•Single profile•Isolated pinnacle reef•Only one additional well •No surface seismic available

Tomographic Velocity Inversion

•Picked Direct Arrivals•3D Thin Layer Model•3D Ray Tracing•Model Interfaces and Layer Parameters Described by Chebyshev Polynomials

Imaging•Kirchhoff Integral•Prestack Reflection Imaging•Depth•Dip Oriented and Aperture Limited•Ray Trace Travel Times from Tomographic Velocities•Angle Gather Output

45 degrees30 degrees 70 degrees

Interpretation Approach

Profile is in DepthExact depth tie at the wells – no time to depth conversion needed

Resolution at the outcrop level – human scale geology

Geological Interpretation versus Geophysical Interpretation

Burnt Bluff Carbonate

Grey Niagaran

Evaporites

ReefZone

Bioherm

Organic Reef

Bioherm

Bioherm

Organic Reef

Bioherm

Organic Reef

Reef Rubble

Organic Reef

Bioherm

Supratidal Island

Bioherm

Organic Reef

Supratidal Island

Tidal Flats

West Texas Permian Reef

•Multiple profiles•More complicated structure•Better well control•Surface seismic available

Left

Middle

Right

Wellman Unit7-6

Wellman Unit7-5

Wellman Unit5-13

Wellman Unit5-11

7-62/27/1981

7-511/13/1973

5-1310/1/1998

5-117/6/1987

<1,363FT> <2,154FT> <1,746FT>

0 100

GAMMA_RAY

6 16

Caliper

0.3 -0.1

Photo Electric

0.3 -0.1

Sonic Porosity

0.3 -0.1

Density Porosity

0 100

GAMMA_RAY

6 16

Caliper

0.3 -0.1

Photo Electric

0.3 -0.1

Sonic Porosity

0.3 -0.1

Density Porosity

0 20

PE

0 100

GAMMA_RAY

6 16

Caliper

0.3 -0.1

Photo Electric

0.3 -0.1

Density Porosity

0 20

PE

0 100

GAMMA_RAY

6 16

Caliper

0.3 -0.1

Photo Electric

0.3 -0.1

Density Porosity

0 20

PE

8000

8100

8200

8300

8400

8500

8600

8700

8800

8900

9000

9100

9200

9300

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9500

9600

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8000

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8600

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8300

8400

8500

8600

8700

8800

8900

9000

9100

9200

9300

9400

9500

9600

9700

4 11.34# J-55

5 1/2 17# N-80

7 5/8 29.7# N-80

7 5/8 29.7# S-95

5 1/2 17# N-80

5 1/2 17# L-80

5 1/2 23# CR-80

7 5/8 29.7# L-80

SubseaTVD(ft)

SubseaTVD(ft)

-4600 -4600

-4700 -4700

-4800 -4800

-4900 -4900

-5000 -5000

-5100 -5100

-5200 -5200

-5300 -5300

-5400 -5400

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-5600 -5600

-5700 -5700

-5800 -5800

-5900 -5900

-6000 -6000

-6100 -6100

-6200 -6200

-6300 -6300

-6400 -6400

-6500 -6500

-6600 -6600

-6700 -6700

Terry Co., Texas

HS=100

PETRA 3/9/2009 4:47:17 PM (Xwell 35 Hz_Interp.CSP)

~ Reef Top

Marker Near OWC

Wellman Unit7-6

Wellman Unit7-5

Wellman Unit5-13

Wellman Unit5-11

7-62/27/1981

7-511/13/1973

5-1310/1/1998

5-117/6/1987

<1,363FT> <2,154FT> <1,746FT>

0 100

GAMMA_RAY

6 16

Caliper

0.3 -0.1

Photo Electric

0.3 -0.1

Sonic Porosity

0.3 -0.1

Density Porosity

0 100

GAMMA_RAY

6 16

Caliper

0.3 -0.1

Photo Electric

0.3 -0.1

Sonic Porosity

0.3 -0.1

Density Porosity

0 20

PE

0 100

GAMMA_RAY

6 16

Caliper

0.3 -0.1

Photo Electric

0.3 -0.1

Density Porosity

0 20

PE

0 100

GAMMA_RAY

6 16

Caliper

0.3 -0.1

Photo Electric

0.3 -0.1

Density Porosity

0 20

PE

8000

8100

8200

8300

8400

8500

8600

8700

8800

8900

9000

9100

9200

9300

9400

9500

9600

9700

9800

9900

8000

8100

8200

8300

8400

8500

8600

8700

8800

8900

9000

9100

9200

9300

9400

9500

9600

9700

9800

9900

8000

8100

8200

8300

8400

8500

8600

8700

8800

8900

9000

9100

9200

9300

9400

9500

9600

9700

9800

9900

8000

8100

8200

8300

8400

8500

8600

8700

8800

8900

9000

9100

9200

9300

9400

9500

9600

9700

4 11.34# J-55

5 1/2 17# N-80

7 5/8 29.7# N-80

7 5/8 29.7# S-95

5 1/2 17# N-80

5 1/2 17# L-80

5 1/2 23# CR-80

7 5/8 29.7# L-80

SubseaTVD(ft)

SubseaTVD(ft)

-4600 -4600

-4700 -4700

-4800 -4800

-4900 -4900

-5000 -5000

-5100 -5100

-5200 -5200

-5300 -5300

-5400 -5400

-5500 -5500

-5600 -5600

-5700 -5700

-5800 -5800

-5900 -5900

-6000 -6000

-6100 -6100

-6200 -6200

-6300 -6300

-6400 -6400

-6500 -6500

-6600 -6600

-6700 -6700

Terry Co., Texas

HS=100

PETRA 3/9/2009 4:47:17 PM (Xwell 35 Hz_Interp.CSP)

~ Reef Top (Erosional)

Marker Near OWC

On Lap

Shaley Lag Deposit

Stacked MoundsStacked Mounds

Inter-Mound COInter-Mound CO33 Debris Debris

Wellman Unit7-6

Wellman Unit7-5

Wellman Unit5-13

Wellman Unit5-11

7-62/27/1981

7-511/13/1973

5-1310/1/1998

5-117/6/1987

<1,363FT> <2,154FT> <1,746FT>

0 100

GAMMA_RAY

6 16

Caliper

0.3 -0.1

Photo Electric

0.3 -0.1

Sonic Porosity

0.3 -0.1

Density Porosity

0 100

GAMMA_RAY

6 16

Caliper

0.3 -0.1

Photo Electric

0.3 -0.1

Sonic Porosity

0.3 -0.1

Density Porosity

0 20

PE

0 100

GAMMA_RAY

6 16

Caliper

0.3 -0.1

Photo Electric

0.3 -0.1

Density Porosity

0 20

PE

0 100

GAMMA_RAY

6 16

Caliper

0.3 -0.1

Photo Electric

0.3 -0.1

Density Porosity

0 20

PE

8000

8100

8200

8300

8400

8500

8600

8700

8800

8900

9000

9100

9200

9300

9400

9500

9600

9700

9800

9900

8000

8100

8200

8300

8400

8500

8600

8700

8800

8900

9000

9100

9200

9300

9400

9500

9600

9700

9800

9900

8000

8100

8200

8300

8400

8500

8600

8700

8800

8900

9000

9100

9200

9300

9400

9500

9600

9700

9800

9900

8000

8100

8200

8300

8400

8500

8600

8700

8800

8900

9000

9100

9200

9300

9400

9500

9600

9700

4 11.34# J-55

5 1/2 17# N-80

7 5/8 29.7# N-80

7 5/8 29.7# S-95

5 1/2 17# N-80

5 1/2 17# L-80

5 1/2 23# CR-80

7 5/8 29.7# L-80

SubseaTVD(ft)

SubseaTVD(ft)

-4600 -4600

-4700 -4700

-4800 -4800

-4900 -4900

-5000 -5000

-5100 -5100

-5200 -5200

-5300 -5300

-5400 -5400

-5500 -5500

-5600 -5600

-5700 -5700

-5800 -5800

-5900 -5900

-6000 -6000

-6100 -6100

-6200 -6200

-6300 -6300

-6400 -6400

-6500 -6500

-6600 -6600

-6700 -6700

Terry Co., Texas

HS=100

PETRA 3/9/2009 4:47:17 PM (Xwell 35 Hz_Interp.CSP)

~ Reef Top

Stacked MoundsStacked Mounds

Inter-Mound COInter-Mound CO33 Debris Debris

Wellman Unit7-6

Wellman Unit7-5

Wellman Unit5-13

Wellman Unit5-11

7-62/27/1981

7-511/13/1973

5-1310/1/1998

5-117/6/1987

<1,363FT> <2,154FT> <1,746FT>

0 100

GAMMA_RAY

6 16

Caliper

0.3 -0.1

Photo Electric

0.3 -0.1

Sonic Porosity

0.3 -0.1

Density Porosity

0 100

GAMMA_RAY

6 16

Caliper

0.3 -0.1

Photo Electric

0.3 -0.1

Sonic Porosity

0.3 -0.1

Density Porosity

0 20

PE

0 100

GAMMA_RAY

6 16

Caliper

0.3 -0.1

Photo Electric

0.3 -0.1

Density Porosity

0 20

PE

0 100

GAMMA_RAY

6 16

Caliper

0.3 -0.1

Photo Electric

0.3 -0.1

Density Porosity

0 20

PE

8000

8100

8200

8300

8400

8500

8600

8700

8800

8900

9000

9100

9200

9300

9400

9500

9600

9700

9800

9900

8000

8100

8200

8300

8400

8500

8600

8700

8800

8900

9000

9100

9200

9300

9400

9500

9600

9700

9800

9900

8000

8100

8200

8300

8400

8500

8600

8700

8800

8900

9000

9100

9200

9300

9400

9500

9600

9700

9800

9900

8000

8100

8200

8300

8400

8500

8600

8700

8800

8900

9000

9100

9200

9300

9400

9500

9600

9700

4 11.34# J-55

5 1/2 17# N-80

7 5/8 29.7# N-80

7 5/8 29.7# S-95

5 1/2 17# N-80

5 1/2 17# L-80

5 1/2 23# CR-80

7 5/8 29.7# L-80

SubseaTVD(ft)

SubseaTVD(ft)

-4600 -4600

-4700 -4700

-4800 -4800

-4900 -4900

-5000 -5000

-5100 -5100

-5200 -5200

-5300 -5300

-5400 -5400

-5500 -5500

-5600 -5600

-5700 -5700

-5800 -5800

-5900 -5900

-6000 -6000

-6100 -6100

-6200 -6200

-6300 -6300

-6400 -6400

-6500 -6500

-6600 -6600

-6700 -6700

Terry Co., Texas

HS=100

PETRA 3/9/2009 4:47:17 PM (Xwell 35 Hz_Interp.CSP)

~ Reef Top

Shaley Lag Deposit

Conclusions

• Depth profiles provide unambiguous well ties• Resolution allows a truer look at the geology• Geophysical effects pushed down to smaller scale• Reservoir level geologic Interpretation is possible

High Resolution Interpretation of a Permian Reef

Michael A. Raines, Sandridge Tertiary, LLC, Thomas R. Morgan*, Ph.D., Schlumberger

Poster PDC P2, Station D1 Tuesday, October 27 at 11:40 a.m.

Acknowledgments:

We would like to thank Sandridge Energy and Michigan Technological University for the use of the data.

References:

Bube, K., and R. Langan, 1999, On a continuation approach to regularization for crosswell tomography: 69th Annual International Meeting, SEG, Expanded Abstracts, 1295-1298.

Liao, Q., and G. A. McMechan, 1997, Tomographic imaging of velocity and Q, with application to crosswell seismic data from the Gypsy Pilot Site, Oklahoma: Geophysics, 62, 1804-1811.

Quan, Y., and J.M. Harris, 1997, Seismic attenuation tomography using the frequency shift method: Geophysics, 62, 895-905.

Huh, M.H., L.I. Briggs, and D. Gill, 1977, Depositional Environments of Pinnacle Reefs, Niagaran and Salina Groups, Northern Shelf, Michigan Basin, in: Studies in Geology No. 5, Reefs and Evaporites – Concepts and Depositional Models, AAPG, J.H. Fisher ed.