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Tom Wilson, Department of Geology and Geography
Environmental and Exploration Geophysics II
Department of Geology and GeographyWest Virginia University
Morgantown, WV
Pitfalls in Seismic InterpretationPitfalls in Seismic Interpretation
Tom Wilson, Department of Geology and Geography
• Exercise IV-VI will be due this Wednesday.
Any Questions ….
• Problems 4.4 and 4.8 are due today.
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Tom Wilson, Department of Geology and Geography
Geometrical and Velocity Pitfalls
Tucker and Yorston
Tom Wilson, Department of Geology and Geography Tucker and Yorston
Velocity pitfalls
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Tom Wilson, Department of Geology and Geography
Tucker and Yorston
Tom Wilson, Department of Geology and GeographyTucker and Yorston
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Tom Wilson, Department of Geology and GeographyTucker and Yorston
Tom Wilson, Department of Geology and Geography Tucker and Yorston
Disconformities and superimposed dip sets
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Tom Wilson, Department of Geology and Geography Tucker and Yorston
Diffraction apex marks the spot.
Tom Wilson, Department of Geology and Geography Tucker and Yorston
“Static” anomalies
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Tom Wilson, Department of Geology and Geography Tucker and Yorston
Tom Wilson, Department of Geology and Geography
Flat Reflector
Apparent structural features are related to variations in thickness of near-surface low-velocity weathered layer.
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Tom Wilson, Department of Geology and Geography
Apparent low in the time structure
Tom Wilson, Department of Geology and Geography
Low to southwest also observed in pre-stack depth converted seismic
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Tom Wilson, Department of Geology and Geography
Note that the lows tend to be concentrated in the valleys
Tom Wilson, Department of Geology and Geography
We actually have a structural high in this area
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Tom Wilson, Department of Geology and Geography
Note that the lows tend to be concentrated in the valleys
Tom Wilson, Department of Geology and Geography Tucker and Yorston
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Tom Wilson, Department of Geology and GeographyTucker and Yorston
Velocities increase with burial depth
Tom Wilson, Department of Geology and Geography
Interval velocities
1500 1900 2300 2700 3100 3500 3900 4300 4700 5100 5500 5900
Trav
el ti
me
0
250500
7501000
12501500
17502000
22502500
27503000
32503500
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Tom Wilson, Department of Geology and Geography
Average Velocity (north sea)
1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500 2600 2700 2800Ti
me
0
250500
7501000
12501500
17502000
22502500
27503000
32503500
Untitled1
Tom Wilson, Department of Geology and Geography Tucker and Yorston
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Tom Wilson, Department of Geology and GeographyTucker and Yorston
Tom Wilson, Department of Geology and GeographyTucker and Yorston
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Tom Wilson, Department of Geology and Geography
Velocity usually increases with Depth
Tom Wilson, Department of Geology and GeographyTucker and Yorston
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Tom Wilson, Department of Geology and GeographyTucker and Yorston
Increased thickness of the high velocity carbonate
Tom Wilson, Department of Geology and GeographyTucker and Yorston
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Tom Wilson, Department of Geology and Geography
Tucker and Yorston
Tom Wilson, Department of Geology and Geography
Tucker and Yorston
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Tom Wilson, Department of Geology and Geography
Tom Wilson, Department of Geology and Geography
Tucker and Yorston
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Tom Wilson, Department of Geology and Geography
Tucker and Yorston
Tom Wilson, Department of Geology and Geography
Tucker and Yorston
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Tom Wilson, Department of Geology and Geography
Tucker and Yorston
Tom Wilson, Department of Geology and Geography
Tucker and Yorston
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Tom Wilson, Department of Geology and Geography
Tucker and Yorston
Tom Wilson, Department of Geology and Geography
Toelle et al, 2007
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Tom Wilson, Department of Geology and Geography
Faults or velocity?
Tom Wilson, Department of Geology and Geography
ErosionalTruncation?
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Tom Wilson, Department of Geology and Geography
Tucker and Yorston
Tom Wilson, Department of Geology and Geography Tucker and Yorston
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Tom Wilson, Department of Geology and Geography
Tucker and Yorston
Tom Wilson, Department of Geology and Geography
Tucker and Yorston
The velocity sag
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Tom Wilson, Department of Geology and Geography
Velocity sag over central diapir?
Velocity sag?
Tom Wilson, Department of Geology and Geography
Tucker and Yorston
The velocity pull-up
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Tom Wilson, Department of Geology and Geography
Structural high/fault or velocity pullup? Central Diapir
Tom Wilson, Department of Geology and Geography
<Western diapir
Western diapir
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Tom Wilson, Department of Geology and Geography
Tom Wilson, Department of Geology and Geography
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Tom Wilson, Department of Geology and Geography
Tom Wilson, Department of Geology and Geography
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Tom Wilson, Department of Geology and Geography
• Exercise V-VI will be due this Wednesday. We’ll discuss problem VI today.
• Problems 4.4 and 4.8 are due today.
Tom Wilson, Department of Geology and Geography
• Read through pages 229 to 232 (static corrections) and look over problem 4.14
• Look over the velocity analysis pitfalls exercise handed out today
Bring questions to class on Monday
