Benefits, Liabilities, and Examples of Seismic Interferometry

1
Benefits, Liabilities, and Examples of Seismic
Interferometry

• Chaiwoot B., W. Cao, S. Dong, Yibo Wang, G.
  Schuster,
• X. Xiao, Yanwei Xu , Jianhua Yu

2
Outline

• Reciprocity Equation Correlation Type

CDP
VSP
SWP
CDP
CDP
CDP
CDP
CDP
VSP
SWP
VSP
VSP
VSP
VSP
VSP
SWP
CDP
CDP
SWP
SWP
SWP
SWP
SWP
VSP
3
Reciprocity Correlation Equation 1D Transmission
Data
B
Im(G(AB))
A
Phase of Common Raypath Cancels
x
4
Reciprocity Correlation Equation 1D Reflection
Data
A
B
Phase of Common Raypath Cancels
x
5
Reciprocity Correlation Equation 1D Reflection
Data
A
B
x
6
Reciprocity Correlation Equation 2D Reflection
Data

k
G(Ax)G(xB)
Im(G(AB))
B
Phase of Common Raypath Cancels
7
General Reciprocity Correlation Eqn. 2D
Reflection Data (Wapenaar, 2004)

2i Im(G(AB)) dG(Ax)G(xB) -
G(Ax)dG(xB)
k
G(Ax)G(xB)
Im(G(AB)
dn
dn
A
B
B
x
x
Phase of Common Raypath Cancels
8
Outline

• Reciprocity Equation Correlation Type

• VSP -gt CDP Transform

• CDPVSP -gt VSP Transform

• CDP-gt CDP Transform

• VSP -gt SWP Transform

• Interferometric Surface Wave Filter

• Poor Mans Superresolution Migration

9
Outline

• Reciprocity Equation Correlation Type

CDP
VSP
SWP
CDP
CDP
CDP
CDP
CDP
VSP
SWP
VSP
VSP
VSP
VSP
VSP
SWP
CDP
CDP
SWP
SWP
SWP
SWP
SWP
VSP
10
Reciprocity Correlation Equation

2i Im(G(AB)) dG(Ax)G(xB) -
G(Ax)dG(xB)
k
G(Ax)G(xB)
Im(G(AB)
dn
dn
well
A
B
x
G(Ax)
11
Reciprocity Correlation Equation
VSP -gt CDP Transform

2i Im(G(AB)) dG(Ax)G(xB) -
G(Ax)dG(xB)
k
G(Ax)G(xB)
Im(G(AB)
dn
dn

2ik
G(Ax)G(xB)
A
B
x
G(Ax)
12
Reciprocity Correlation Equation
VSP -gt CDP Transform

G(Ax)G(xB)
Im(G(AB))
k
well
A
B
x
G(Ax)
13
Reciprocity Correlation Equation
VSP -gt CDP Transform

G(Ax)G(xB)
Im(G(AB))
k
well
Transform Multiples into Primaries
14
Benefit
Superillumination

G(Ax)G(xB)
Im(G(AB))
k
well
Standard VSP Primary
VSP -gt CDP
15
VSP -gt CDP Transform Numerical Tests

1. Synthetic VSP Data
2. 2D VSP Land Data
3. 2D VSP Marine Data
4. 3D VSP Marine Data

16
VSP Images with Static Errors
Kirchhoff Mig.
Interferometric Mig.
0.5 km 2.5 km
0.5 km 2.5 km
0.5 km 2.5 km
0.5 km 2.5 km
17
VSP -gt CDP Transform Numerical Tests

1. Synthetic VSP Data
2. 2D VSP Land Data
3. 2D VSP Marine Data
4. 3D VSP Marine Data

18
VSP Multiple (12 receivers 13 kft _at_ 30 ft
spacing 500 shots)
5000
Depth (ft)
13000
X (ft)
0
56000
19
Surface Seismic
5000
Depth (ft)
13000
X (ft)
0
56000
20
VSP Multiple (12 receivers 13 kft _at_ 30 ft
spacing 500 shots)
5000
Depth (ft)
13000
X (ft)
0
56000
21
VSP -gt CDP Transform Numerical Tests

1. Synthetic VSP Data
2. 2D VSP Land Data
3. 2D VSP Marine Data
4. 3D VSP Marine Data

22
Exxon Field VSP Data
23
Depth (ft)
30
900
0
Raw Data(CRG15)
G(Ax)
Time (s)
G(Bx)
0.3
24
Field RVSP Images with Static Errors
Kirchhoff Mig.
Interferometric Mig.
X (m)
1000
0.0 km .9 km
950
Depth (m)
1950
0.0 km .12 km
0.0 km .12 km
25
Primaries and multiples migration
(background is CDP stack)
100
Time (ms)
geophones
1600
26
VSP -gt CDP Transform Numerical Tests

1. Synthetic VSP Data
2. 2D VSP Land Data
3. 2D VSP Marine Data
4. 3D VSP Marine Data

27
3D SEG Salt Model Test
28
VSP Multiples Migration
Stack of 6 receiver gathers
( Courtesy of P/GSI ¼ million traces, 3 GB
memory, 4 hours on a PC )
29
GOM Field 3D VSP Data Application
30
3D VSP Acquisition
11 km
11 km
4.5 km deep
12 geophones at an interval of 15.25 m.
31
3D Migration Result
Migration of only one receiver gather
32
A 2D Image Slice after Stack
0
Depth (m)
Coherent Noise Mismigrated Primary
6500
Offset (m)
11000
0
33
Summary

G(Ax)G(xB)
Im(G(AB)
k
well
Benefits
Liabilities
34
Outline

• Reciprocity Equation Correlation Type

CDP
VSP
SWP
CDP
CDP
CDP
CDP
CDP
VSP
SWP
VSP
VSP
VSP
VSP
VSP
SWP
CDP
CDP
SWP
SWP
SWP
SWP
SWP
VSP
35
Reciprocity Correlation Equation
CDP -gt CDP Transform
Im(G(AB)
S
x
A
B
36
Reciprocity Correlation Equation
CDP -gt CDP Transform
Im(G(AB)
S
x
A
B
37
BenefitsDistinguish Mult. From Prim.
38
Key Idea Migrate Primaries And Water Multiples
Depth (km)
4
15
0
Distance (km)
39
Pick Traveltime of Water Bottom Reflection
0
Depth (km)
4
15
0
Distance (km)
40
M(x) d(s,g, )
Mult.
T
sg
0
Depth (km)
4
15
0
Distance (km)
41
2-D SEG/EAGE Salt Model
0
Depth (km)
4
15
0
Distance (km)
42
Kirchhoff Depth Migration (Primary)
0
Depth (km)
4
15
0
Distance (km)
43
Kirchhoff Depth Migration (Ghost)
0
Depth (km)
4
15
0
Distance (km)
44
Primary Ghost
0
Depth (km)
4
15
0
Distance (km)
45
Weighted Ghost Primary
46
BenefitsInterpolating Near Offset Missing Data
47
Original Data
0
Second (s)
1.0
Offset (m)
1390
0
48
Near Offset Missing Data
0
Second (s)
1.0
Offset (m)
1390
0
49
Pseudo Primaries
0
Second (s)
1.0
Offset (m)
1390
0
50
Interferometric Interpolation Result
0
Pseudo Primaries
Original Data
Second (s)
1.0
Offset (m)
1390
0
51
Interferometric Interpolation Result
0
Pseudo Primaries
Original Data
Second (s)
1.0
Offset (m)
1390
0
52
Summary

G(Ax)G(xB)
Im(G(AB)
k
well
Benefits
Liabilities
53
Outline

• Reciprocity Equation Correlation Type

CDP
VSP
SWP
CDP
CDP
CDP
CDP
CDP
VSP
SWP
VSP
VSP
VSP
VSP
VSP
SWP
CDP
CDP
SWP
SWP
SWP
SWP
SWP
VSP
54
Reciprocity Correlation Equation
VSP -gt CDP Transform
VSP -gt SWP Transform
2i Im(G(AB)
A
B
x
G(Ax)
55
Reciprocity Correlation Equation
VSP -gt CDP Transform
VSP -gt SWP Transform
2i Im(G(AB)
surface
B
A
x
56
Reciprocity Correlation Equation
VSP -gt SWP Transform
VSP -gt CDP Transform
Benefits SuperresolutionStatics
57
A Salt Flank Imaging Example
10 shots
Overburden
94 geophones
58
Interferometric Imaging
2700
Depth (m)
5500
0
Offset (m)
1700
59
Interferometric VSP Flank Imaging
0 700 m
(Hornby et al, 2006, The Leading Edge)
60
Interferometric VSP Flank Imaging
(Hornby et al, 2006, The Leading Edge)
0 700 m
61
Interferometric VSP Flank Imaging
(Hornby et al, 2006, The Leading Edge)
0 700 m
62
Interferometric VSP Flank Imaging
(Hornby et al, 2006, The Leading Edge)
0 700 m
63
Reciprocity Correlation Equation
VSPCDP -gt SWP Transform
VSP -gt CDP Transform
64
CDP Data
3
0
0
Depth (km)
1.8
X (km)
65
CDP Data
Virtual VSP Data
3
0
0
Depth (km)
1.8
X (km)
66
CDP Data
CDPVirtual VSP Data
3
0
0
Depth (km)
1.8
X (km)
67
CDP Data
CDPVirtual VSP Data
Redatumed CDPVirtual VSP Data
3
0
0
Depth (km)
1.8
X (km)
68
Redatumed CDPVirtual VSP Data
3
0
0
Depth (km)
1.8
X (km)
69
X (km)
0
3
0
Time (s)
3
CSG 100
70
Standard CDP Migration with Wrong Overburden
Velocity
X (km)
0
3
0
Depth (km)
1.8
71
Interferometric CDP Migration with Wrong
Overburden Velocity
X (km)
0
3
0
Depth (km)
1.8
72
Standard Migration
Interferometric Migration
Standard Migration
Correct Velocity
Incorrect Velocity
X (km)
X (km)
X (km)
3
3
3
0
0
0
0
Depth (km)
1.8
73
Summary

G(Ax)G(xB)
Im(G(AB)
k
well
Benefits
Liabilities
74
Outline

• Reciprocity Equation Correlation Type

CDP
VSP
SWP
CDP
CDP
CDP
CDP
CDP
VSP
SWP
VSP
VSP
VSP
VSP
VSP
SWP
CDP
CDP
SWP
SWP
SWP
SWP
SWP
VSP
75
Outline

• Reciprocity Equation Correlation Type

• VSP -gt CDP Transform

• CDPVSP -gt VSP Transform

• CDP-gt CDP Transform

• VSP -gt SWP Transform

• Interferometric Surface Wave Filter

• Poor Mans Superresolution Migration

76
Prediction of Surface Waves
77
The work flow
78
Aramco Data
Original data from Saudi Arabia
Remove surface waves only by NLF
79
Aramco Data
Remove surface waves Int.NLF
Original data from Saudi Arabia
80
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81
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82
China Data
0
Time (s)
2.0
0
3600
Receiver (m)
83
Outline

• Reciprocity Equation Correlation Type

• VSP -gt CDP Transform

• CDPVSP -gt VSP Transform

• CDP-gt CDP Transform

• VSP -gt SWP Transform

• Interferometric Surface Wave Filter

• Poor Mans Superresolution Migration

84
Salt Model
0.0
Depth (km)
Model
3.8
X (km)
0 km
16 km
85
Common Offset Data
0.0
Time (s)
Data
5.0
X (km)
0 km
16 km
86
Kirchhoff Image
0.0
Depth (km)
3.8
X (km)
0 km
16 km
87
Interferomteric Image
0.0
Depth (km)
3.8
X (km)
0 km
16 km
88
Outline

• Reciprocity Equation Correlation Type

• VSP -gt CDP Transform

• CDPVSP -gt SWP Transform

• CDP-gt CDP Transform

• VSP -gt SWP Transform

• Interferometric Surface Wave Filter

• Poor Mans Superresolution Migration

89
Outline
CDP
VSP
SWP
CDP
CDP
CDP
CDP
CDP
VSP
SWP
VSP
VSP
VSP
VSP
VSP
SWP
CDP
CDP
SWP
SWP
SWP
SWP
SWP
VSP
90
Reciprocity Correlation Equation
VSPCDP -gt VSP Transform
Im(G(AB)
S
x
A
B
91
Reciprocity Correlation Equation VSPCDP -gt VSP
Phase of Common Raypath Cancels
92
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93
Outline

• Reciprocity Equation Correlation Type

• VSP -gt CDP Transform

• CDPVSP -gt SWP Transform

• CDP-gt CDP Transform

• VSP -gt SWP Transform

• Interferometric Surface Wave Filter

• Poor Mans Superresolution Migration

94
CDP Redatuming Interferometry
95
Field Data stack
Offset (km)
0
12
0.5
990 shots
180 geophones
Interval 25 m
Two-way Time (s)
trace length 8.188 s
sample interval 4 ms
4.0
Stack section (courtesy of Jianming Sheng)
96
Field Data
12
Offset (km)
0
0
One-way Time (s)
1.5
Time Migration with NMO Velocity
97
Natural Redatumed Field Data
12
Offset (km)
0
0
One-way Time (s)
1.5
Time Migration with NMO Velocity
98
Standard Time Migration
Offset (km)
8
11
1.0
Two-way Time (s)
1.6
99
Interferometric Migration
Offset (km)
8
11
1.0
Two-way Time (s)
1.6
100
Reduced Time Migration
Offset (km)
8
11
1.0
Two-way Time (s)
1.6
101
Outline

• Reciprocity Equation Correlation Type

• VSP -gt CDP Transform

• CDPVSP -gt VSP Transform

• CDP-gt CDP Transform

• Interferometric Surface Wave Filter

• Poor Mans Superresolution Migration

• VSPCDP -gt VSP

102
Outline

• Overview
• Surface Multiple Migration
• Interbed Multiple Migration
• Multiple Attenuation in
• Multiple Imaging
• Conclusions

103
Outline

• Overview
• Multiple Attenuation in
• Multiple Imaging
• Motivation
• Methodology
• Numerical Examples
• Summary

104
A major problem with multiple imaging
high-order multiple
Incorrectly positioned as low-order multiple
105
Outline

• Overview
• Multiple Attenuation in
• Multiple Imaging
• Motivation
• Methodology
• Numerical Examples
• Summary

106
Step1 Prediction
second-order multiple
107
Physics Behind Prediction
D(g s) ? G(g g) D(g s) dg
D(gs) Downgoing component
G(gg) Greens function for
propagating the wavefield
D(gs) Predicted high-order multiples
108
Step2 Subtraction
p(t) y(t) - ? fj(t)?mj(t)
Predicted high-order multiple
Original data
High-order multiple-free data
109
Generalized-Source Migration
Generalized-source wavefield
Reflection wavefield
110
Outline

• Overview
• Multiple Attenuation in
• Multiple Imaging
• Motivation
• Methodology
• Numerical Examples
• Summary

111
Numerical Examples

• Synthetic Data Test
• Field Data Test

112
Density Model
276 shots, 50m spacing
0
20 receivers 6.25m spacing
Depth (m)
6,000
14,000
0
X (m)
113
CRG1 Different Order Multiples
114
Before Attenuation
0.4
Time (sec)
2.5
0
14,000
X (m)
115
Prediction
0.4
Time (sec)
2.5
0
14,000
X (m)
116
After Attenuation
0.4
Time (sec)
2.5
0
14,000
X (m)
117
Before Attenuation
0.4
Time (sec)
2.5
0
14,000
X (m)
118
Migration Image Before Attenuation
500
Interference from high-order multiple
Depth (m)
6000
12500
1500
X (m)
119
Migration Image After Attenuation
500
Depth (m)
6000
12500
1500
X (m)
120
Numerical Examples

• Synthetic Data Test
• Field Data Test

121
Velocity Model
0
V (ft/s)
4910
Depth (ft)
14300
43000
0
60000
X (ft)
122
Different Order Multiples
123
Before Attenuation
1.25
1st-order multiple
Time (sec)
2nd-order multiple
5.00
0
60000
X (ft)
124
Predicted Multiple
1.25
Time (sec)
5.00
0
60000
X (ft)
125
After Attenuation
1.25
Time (sec)
5.00
0
60000
X (ft)
126
Before Attenuation
1.25
1st-order multiple
Time (sec)
2nd-order multiple
5.00
0
60000
X (ft)
127
Multiple Migration Image Before Attenuation
10
interference from high-order multiple
Depth (kft)
26
X (kft)
16
32
128
Multiple Migration Image After Attenuation
10
Depth (kft)
26
X (kft)
16
32
129
Multiple Migration Images Comparison
10
Depth (kft)
26
X (kft)
16
32
130
Overview

• CDP Interferometric Interpolation

• Interferometric Surface Wave Filter

• CDPVSP -gt VSP Transform

• Migration Deconvolution New Pemex

• Poor Mans Superresolution Migration

• Reverse Time Migration

131
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132
Standard Migration
Migration Deconvolution
vs
0 3.5 s
(courtesy of PEMEX)
133
PEMEX Prestack Migration Image
The CSG d
0.5 s
Time (s)
Time (s)
1.7 s
Receiver (m)
X (km)
0
3600
0 km
5 km
The original data from Saudi
Remove surface waves only by NLF
134
PEMEX Prestack Migration Image
The CSG d
0.5 s
Time (s)
Time (s)
1.7 s
Receiver (m)
X (km)
0
3600
0 km
5 km
The original data from Saudi
Remove surface waves only by NLF
135
MD Goal

• MDAttributes

136
Overview

• CDP Interferometric Interpolation

• Interferometric Surface Wave Filter

• CDPVSP -gt VSP Transform

• Migration Deconvolution New Pemex

• Poor Mans Superresolution Migration

• Reverse Time Migration

137
Overview

• CDP Interferometric Interpolation

• Interferometric Surface Wave Filter

• CDPVSP -gt VSP Transform

• Migration Deconvolution New Pemex

• Poor Mans Superresolution Migration

• Reverse Time Migration

138
Reverse Time Migration

• FPGA and RTM (Brown)

• Fast 3D Reverse Time Datum (Dong)

• Reverse Time Migration POIC (Cao)

• Waveform Inversion Saudi

• Interferometric Redatuming Saudi

139
Overview

• CDP Interferometric Interpolation

• Interferometric Surface Wave Filter

• CDPVSP -gt VSP Transform

• Migration Deconvolution New Pemex

• Poor Mans Superresolution Migration

140
01. Field data
02. Pick first break
03. Refraction traveltime tomography
reference
04. Pick reference layer in tomogram
05. Calculate reference reflection time
10. Reduced time migration
141
01. Field data
Wavelet Deconvolution
02. Pick first break
03. Refraction traveltime tomography
Elevation statics correction
Velocity analysis
reference
04. Pick reference layer in tomogram
First stack
05. Calculate reference reflection time
Residual statics correction
Velocity analysis
NMO velocity
10. Reduced time migration
Brute stack
142
01. Field data
Wavelet Deconvolution
02. Pick first break
06. Pick reference reflection time in seismogram
03. Refraction traveltime tomography
Elevation statics correction
07. Estimate one-way time to reference layer
Velocity analysis
reference
04. Pick reference layer in tomogram
08. Datum receivers to reference layer
First stack
05. Calculate reference reflection time
Residual statics correction
09. Datum sources to reference layer
Velocity analysis
NMO velocity
10. Reduced time migration
11. Interferometric migration
Brute stack
143
Geometry
Elevation
Plan view
18
180
Elev (m)
X (m)
0
0
0
5
0
Y (km)
Y (km)
5
144
Stacked section before statics correction
0
Time (s)
2
Stacked section after statics correction
0
Time (s)
2
0
1100
CDP number (5m)
145
Vel (m/s)
NMO velocity after statics correction
0
4000
Time (s)
2
1600
Vel (m/s)
Traveltime tomogram
0
6000
Depth (m)
800
0
0
CDP number (5m)
1100
146
Imaging Multiples
1. Turn Primaries into Multiples, then Subtract

2. Turn Multiples into Primaries, then Migrate
147
Imaging Multiples
1. Turn Multiples into Primaries, then Migrate
2. Turn Multiples into Primaries, then Migrate
148
Why Image Multiples in VSP Data?
149
Why Image Multiples in VSP Data?
150
PEMEX Prestack Migration Image
The CSG d
0.5 s
Time (s)
Time (s)
1.7 s
Receiver (m)
X (km)
0
3600
0 km
5 km
The original data from Saudi
Remove surface waves only by NLF
151
Why Image Multiples in VSP Data?
152
VSP Multiple (12 receivers 13 kft _at_ 30 ft
spacing 500 shots)
5000
Depth (ft)
13000
X (ft)
0
56000
153
CDP Surface Seismic
5000
Depth (ft)
13000
X (ft)
0
56000
154
VSP Multiple (12 receivers 13 kft _at_ 30 ft
spacing 500 shots)
5000
Depth (ft)
13000
X (ft)
0
56000
155
A Real Walkaway VSP Experiment
0
401 shots on a topographic surface
well
Depth (m)
1400
12 geophones at 1400 - 1500 m depth
1500
0
10000
Offset (m)
156
A Common Receiver Gather
0.4
Time (s)
1.8
0
10000
Offset (m)
157
Work flow
Separate up and down going wavefields
Upgoing wavefield
Downgoing wavefield
Statics
Statics
Statics
Ray tracing
Pick first-break
Specular interferometry
Primaries migration
Multiples migration
158
Standard vs Interferometry Mig VSP (Narrow vs
Wide Illumination)
100
Time (ms)
geophones
1600
159
Why Image Multiples in CDP Data?
160
Imaging Multiples
1. Turn Multiples into Primaries, then Migrate
161
CDP Multiples Migration
162
Primary vs Multiple MigrationSynthetic Shot
Gather
Primaries migration in one CSG
Multiples migration in one CSG
163
Primary vs Multiple MigrationUnocal Shot Gather
Primaries migration in one CSG
Multiples migration in one CSG
164
Overview

• Imaging Multiples

• Waveform Inversion

• CDP Interferomtery

• Migration Deconvolution

• Scattering Deconvolution

165
Traveltime Tomography vs Waveform Inversion of
Early Arrivals
Early Arrival Waveform Tomography -gt
SharpSmoothDeeper V(x,z)
166
Early Arrival Waveform Tomography Strategy
1. Window about early arrivals Avoid Local
Minima problems
167
Synthetic Model
168
Traveltime Tomogram
169
Velocity Model
170
Saudi Land Survey
1. 1279 CSGs, 240 traces/gather
2. 30 m station interval, max. offset 3.6km
3. Line Length 46 km
4. Pick 246,000 traveltimes
5. Traveltime tomography -gt V(x,y,z)
171
Brute Stack Section
0
Time (s)
2.0
3920
5070
CDP
172
TomostaticsStacking
0
Time (s)
2.0
3920
5070
CDP
173
EWTStacking
0
Time (s)
2.0
3920
5070
CDP
174
Conclusion
175
Overview

• Imaging Multiples

• Waveform Inversion

• CDP Interferomtery

• Migration Deconvolution

• Scattering Deconvolution

176
SummaryInterferometric CDP Datuming
177
Overview

• Imaging Multiples

• Waveform Inversion

• CDP Interferomtery

• Migration Deconvolution

• Scattering Deconvolution

178
Prestack Time Migration Deconvolution for
VSPMarine CDP Data
179
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180
Recording Geometry
181
MIG
MD
Depth Slices
Z1 km
Z3 km
Z5 km
182
MIG
MD
Depth Slices
Z7 km
Z9 km
Z10 km
183
Meandering Stream Model
2.5 km
2.5 km
0
0
184
Mig
Z3.5 KM
Model
MD
185
VSP Geometry source 21 x 21 geophone 12
Migration
MD
Depth1.75 km
186
3-D SEG/EAGE Salt Model
12.2 km
12.2 km
0
0
Imaging dxdy20 m
187
3-D SEG/EAGE Salt Model
Y7.12 km
X (km)
Y (km)
188
Mig (z1.2 km)
X (km)
X (km)
5
9.8
5
9.8
3
Y (km)
10
189
MD
X (km)
0
6
0
PSTMD
PSTM(courtesy of Unocal)
Time (s)
8
190
MD
X (km)
0
6
3
Time (s)
8
191
MD
Mig (courtesy of Aramco)
Time (s)
192
Mig (courtesy of Unocal)
MD
Inline Number
1
90
90
Inline Number
1
1.1
Depth (kft)
7.0
(Crossline50)
193
(No Transcript)
194
MD
Mig
(3.6 kft)
195
Standard Migration
Migration Deconvolution
vs
0 3.5 s
(courtesy of PEMEX)
196
Conclusions
MD reduces migration artifacts
197
Overview

• Imaging Multiples

• Waveform Inversion

• CDP Interferomtery

• Migration Deconvolution

• Reverse Time Datuming

198
Why RTD?
SMAART JV. Pluto 1.5 Vp model
0
Depth (Km)
9
0
30
Distance (km)
199
Why RTD?
POIC image
KM image
6
Depth (km)
9
5
25
5
25
Distance (km)
Distance (km)
200
Why RTD?
Offset (km)
Complex Rough topography Large velocity variation
RTD
Depth (Km)
Less Complex
201
Implement RTD
S
r
Depth
d(xx)g(sx) d(sx)
x
x
Distance
202
Implement RTD
d(sr)
S
R
g(sx)
Depth
x
x
Target-oriented RTD (LuoSchuster , 2002)
Distance
203
Outline

• POIC Review

• RTDPOIC
• SMAART Data
• Conclusions

204
Why RTD
SMAART JV. Pluto 1.5 Vp model
0
Depth (Km)
9
0
30
Distance (km)
205
SMAART JV Data
206
KM Depth Images
After Datuming
Before Datuming
6
Depth (km)
9
5
25
5
25
Distance (km)
Distance (km)
207
POIC Depth Images
After Datuming
Before Datuming
6
Depth (km)
9
5
25
5
25
Distance (km)
Distance (km)
208
Depth Images after Redatuming
Reflectivity Model
KM image
6
Depth (km)
9
5
25
5
25
Distance (km)
Distance (km)
209
Depth Images after Redatuming
POIC image
KM image
Depth (km)
Distance (km)
Distance (km)
210
Outline

• POIC Review

• RTDPOIC
• SMAART Data
• Conclusions

211
Conclusions (RTDPOIC)

• RTD helps reveal deeper structure

• RTD KM provides good depth image

• RTD POIC helps to suppress multiples
  and preserve the primaries

212
Overview

• Imaging Multiples

• Waveform Inversion

• CDP Interferomtery

• Migration Deconvolution

• Scattering Deconvolution

213
CDP Transfer Function Deconvolution
D(sx) T(sx)
T(xg)
overburden
214
CDP Transfer Function Deconvolution
0 0.6
0 600
Depth (m)
Time (s)
0 0.6
0 0.6
Time (s)
Time (s)
0 600 m
0 600 m
X (m)
X (m)
215
CDP Transfer Function Deconvolution
0 0.6
0 600
Reflections
Depth (m)
Time (s)
0 0.6
0 0.6
Time (s)
Time (s)
0 600 m
0 600 m
X (m)
X (m)
216
CDP Transfer Function Deconvolution
0 0.6
0 600
Reflections
Depth (m)
Time (s)
0 0.6
0 0.6
Scattering
Time (s)
Time (s)
0 600 m
0 600 m
X (m)
X (m)
217
CDP Transfer Function Deconvolution
0 0.6
0 600
Reflections
Depth (m)
Time (s)
0 0.6
0 0.6
Scattering
ScatteringReflections
Time (s)
Time (s)
0 600 m
0 600 m
X (m)
X (m)
218
CDP Transfer Function Deconvolution
Mig. Of Data w/o Scattering
Mig.Decon of Data with Scatter
0 X (m) 600 m
0 X (m) 600 m
219
FD Experiment
1500
0
Generalized-source wavefield
Dpeth (m)
Time (s)
Reflection wavefield
3500
3
Offset (m)
1000
Depth (m)
3500
0
1500
220
GSM Results
GSM of one shot gather
GSM of three shot gathers
1500
Dpeth (m)
3500
Offset (m)
1000
Offset (m)
1000
0
0
221
Reduced Form GSM
Ray tracing of line source (picked direct
wave)
Reduce form GSM result
1500
Dpeth (m)
3500
Offset (m)
0
1000
Offset (m)
0
1000
222
Conclusion
223
Overview

• Transfer Function Deconvolution

• Waveform Inversion

• CDP Specular Interferomtery

• VSP Specular Interferometry

• Refraction Interferometry

224
Conclusion
225
(No Transcript)
226
Reciprocity Correlation Equation Lucky 2D
Reflection Data

k
G(Ax)G(xB)
Im(G(AB)
B
Phase of Common Raypath Cancels