ESCI 444Exploration Geophysics II Reflection Seismic Data Processing

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ESCI 444-Exploration Geophysics IIReflection
Seismic Data Processing
Spring, 2007

• Steve H. Danbom, Ph.D., P.G.
• Adjunct Professor
• Office - Room 206A
• Office Hours By Appointment

Lecture Week 11 Processing seismic
reflections amplitude anomalies
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Not everything is exactly as portrayed.
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Positive reflection coefficient at A reflects
back scaled version of downgoing pulse, while
that of B is oppositely signed
resulting composit wavelet is simple sum as parts
do not overlap.
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On the other hand, if the separation between
reflectors A and B dimishes to a thickness of
one-quarter of a wavelength, then the composite
waveform reflection parts are in phase.
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One axiom from quarter-wavelength, thin-bed
tuning.
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Restating quarter-wavelength, thin-bed tuning.
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Velocity model and resulting normal-incident
synthetic seismogram showing thin-bed quarter
wavelength tuning.
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Schematic illustrating the tuning effect for a
thinning bed.
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Comparison of hydrocarbon amplitude anomalies
using variable areawiggle vs. a color display
designed to eliminate phase bias.
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Hydrocarbon indicators a partial list
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Soheres an axiom for PP, PS, and SS exploration
for gas
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Current thinking on AVO for P waves
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A list of attribute sections used in reflection
seismology.
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Petronius Field Tie of Synthetic and Seismic
Water Sands
Oil Sands
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Mensa Field Tie of Synthetic Seismic Stack
MC 731 1 Syn.
3.0
Time (sec)
3.5
4.0
Detailed
4.5
5.0
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Mensa Field Tie of Synthetic Seismic Gather
Offset in 103 ft
Offset in 103 ft
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1
10
15
5
1
10
15

35o
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Genesis Field Tie of Synthetic Seismic Stack
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Auger Field Base Map Showing Lines Wells
Auger Dome
GB 427 A-11 ST3
GB 470 1
GB 516 1
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Auger Field Geology from McGee, et al., 1994
SW
NE
Out of the plane reflection of salt neck.
4.0
5.0
GAS
OIL
SALT
6.0
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Auger Field 0 to 8o Stack
SW
NE
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Auger Field 16 to 24o Stack
SW
NE
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Mars Field Tie of Synthetic and Seismic Stack
SE
NW
MC 807 1
Water Bottom
Time (sec)
2.0
MARS BASIN
3.0
Anatares Salt Body
4.0
Venus Salt Body
5.0
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Mars Field Tie of Synthetic and Seismic Stack
MC 807 1
NW
SE
Syn.
3.5
Time (sec)
4.0
Anatares Salt Body
4.5
Venus Salt Body
5.0
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Mars Field Class 2 Class 3 AVO
0.5 ln (AI)
Est. Poissons Ratio
Class 3 AVO
Pliocene
Note Progressive Decrease of AI Increase of
PR for Increasing Depth of Reservoir
Miocene
Class 2 AVO
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Mars Field 0 to 8o Stack
SP
2900
NW
SE
Time (sec)
4.0
4.5
5.0
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SP
2900
Mars Field 16 to 24o Stack
NW
SE
Time (sec)
4.0
4.5
5.0
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SP
Mars Field NI x PR Section
NW
SE
Time (sec)
4.0
4.5
5.0
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SP
2900
NW
SE
Mars Field AVO Crossplot (NI x PR) Section
Time (sec)
4.0
4.5
5.0
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Hoover Field - Pay vs. Dry Hole
AC 25 1 Hoover Field
EB 994 1 Dry Hole
Seismic Line 1621-45
3.5
4.0
10,000 ft
Common sand shown with arrows
Gamma Ray Curve
11,000 ft
Resistivity Curve
12,000 ft
AC 25 1 projected 5,000 ft onto seismic
line that traverses edge of field
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Hoover Field -- 0 to 30o Stack
4.0
Line 1621 showing sand with water
Line 622 showing sand with oil
4.0
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Diana Field 2-D Wedge Model (Gas/Oil/Water)
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Diana Field NI Seismic Section
NW
SE
3.0
Time (sec)
3.5
GAS/OIL
OIL/WATER
4.0
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Diana Field NI x PR Seismic Section
NW
SE
3.0
3.5
GAS/OIL
OIL/WATER
4.0
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Diana Field 0 to 30o Stack Section
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Diana Field Seismic Gathers (GasOilWater)
Diana Reservoir with Gas
Diana Reservoir with Oil
Diana Reservoir with Water
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