Transcript No Slide Title

Raw Seismograms
6.0
Time (s)
0
-6.0
0.8
Four-Layer Sand Channel Model
1.5
Depth (m)
0
-1.5
2100
0
Midpoint (m)
2100
Interferometric Seismic
Imaging
J. Yu, J. Sheng, and G. Schuster
SELECTIVE HISTORY PASSIVE IMAGING
Validity
Earthquake 1900’s
xx
Claerbout,
Katz, 70’s
Migrate
xx
Utah+LLNL 1997
xy
Claerbout,
Rickett 1999
Migrate
xy
Arbitrary Unknown Src V(z)
W(t)
Location
V(x,y,z)
NO
YES
YES
YES
NO
YES/NO
YES
NO
YES
NO
YES
YES/NO
YES
YES
YES YES
YES NO?
YES
YES
Outline
• Interferometric Principle:
Time Diff. between Arrivals
Structure Diff.
• Interferometric Imaging Applications:
Passive data for IVSP while Drilling
Imaging of Free Surface CDP Multiples
Imaging of Hydo-Frac Location
Transmission PS Migration
Interference Pattern
Optical
Optical Lens
Lens
t
LASER
Interference Pattern
s
s
Optical Lens
t
LensLASER
Deformation
Time Differences
Outline
• Interferometric Principle:
Time Diff. between Arrivals
Structure Diff.
• Interferometric Imaging Applications:
Passive data for IVSP while Drilling
Seismic Ghost Reflection
Ghost
Direct
Find R(x,z) but not know source location
?
Seismic Seismic
Interferogram:
Correlate Traces
Ghost Reflection
Master
Ghost x Direct
Direct x Direct
1
}2
t
M
Kirchhoff Migrate psuedo-shot gathers
m(x) =
g
(g, tgx + tMx )
M
Geological Model
0
0
X (m)
4
Depth (m)
V1
V2
V3
V4
V5
3
V6
Shot Gather and Crosscorrelogram
0
Time (s)
200
Time (s)
0
1
Traces
4
4
1
Traces
CSG 10 and Master trace at 80
200
Crosscorrelogram Migration Results
1.6
X (km)
1.6
X (km)
Time (s)
0
2.1
2.2
With primary
Without primary
2.1
Problems in RVSPWD
Geophone
Source
Pilot signal?
Wavelet ?
Bit Position?
What is Joint Migration
Well
Receiver
Ghost
Direct
Wave
Primary
Drill bit
Acquisition Survey
East (kft)
0
0
Drill bit
Well Rig
-5
Depth (kft)
0
10
4.5
Autocorrelograms of CSG 96
1
10
1
10
1
10
Time (s)
0
4
8s
12 s
16 s
Acquisition Survey Map
Well Rig
North (ft)
0
Drill bit
-5000
0
1500
3000
East (ft)
4500
Joint Migration ( insert) and CDP Section
SP
Drilling
1.0
Time (s)
hole
2.0
3.0
1255
1235
1215
Outline
• Interferometric Principle:
Time Diff. between Arrivals
Structure Diff.
• Interferometric Imaging Applications:
Passive data for IVSP while Drilling
Imaging of Free Surface CDP Multiples
Free-Surface Multiple
Ghost
Primary
1
2
Seismic Interferogram: Correlate Traces
Ghost x Primary
Primary x Primary
}2
1
t
Kirchhoff Migrate psuedo-shot gathers
m(x) =
g
(g, tgx + tMx )
M
3
Caution: Ghost x Primary = R
SEG/EAGE Salt Model
320 shots
176 traces per shot
0
600
1200
1800
2400
3000
3600
0
5000 Distance (m) 10000
15000
Kirchhoff Image
Distance (m)
0
600
1200
1800
2400
3000
3600
0
5000
10000
15000
XcorM
Distance (m)
0
600
1200
1800
2400
3000
3600
0
5000
10000
15000
KM
 XcorM
Distance (m)
0
600
1200
1800
2400
3000
3600
0
5000
10000
15000
Kirchhoff Image
Distance (m)
0
600
1200
1800
2400
3000
3600
0
5000
10000
15000
Outline
• Interferometric Principle:
Time Diff. between Arrivals
Structure Diff.
• Interferometric Imaging Applications:
Passive data for IVSP while Drilling
Imaging of Free Surface CDP Multiples
Imaging of Hydo-Frac Location
Hydro-Fracturing=Unknown Source
P
P
1
P
2
P
x
?
Hydro-Fracturing=Unknown Source
Master
S
P*P
P*P
P
}
1
2
P
x
P
Difference between Paths
t
Kirchhoff Migrate psuedo-shot gathers
m(x) =
g
(g, tgx - tMx )
M
70 Ringy 30 Hz Seismograms
1.0
Time (s)
0
-1.0
0.8
Kirchhoff Migration Image
0
1.0
-1.0
2100 m
Correlogram Migration Image
0
1.0
-1.5
2100 m
0
Midpoint (m)
2100
70 Raw Seismograms
1.0
Time (s)
0
0.8
-1.0
Migration
Migration Image:
Image: 1-s
1-s Stack
Stack
0
6.0
-6.0
2100 m
Migration Image: 40-s Stack
0
1.5
-1.5
2100 m
0
Midpoint (m)
2100
Outline
• Interferometric Principle:
Time Diff. between Arrivals
Structure Diff.
• Interferometric Imaging Applications:
Passive data for IVSP while Drilling
Imaging of Free Surface CDP Multiples
Imaging of Hydo-Frac Location
Transmission PS Migration
Seismic P and PS Transmission
P
S
S
P
Find R(x,z)
?
P and
PS Transmission
Interferograms
Seismic
P and PS Transmission
Master
P*S
P
S*S
S
}
1
2
S
P
x
Difference between Paths
t
Kirchhoff Migrate psuedo-shot gathers
m(x) =
g
(g, tgx - tMx )
M
0 km
0s
1.6 s
200 km
m(x) =
(g, tgx + t )
Summary
Mx
M g
1. New Passive Seismic Imaging Capability:
Valid for V(x,y,z)
Src & R Images
Poststack & Prestack
Arbitrary Sources
2. Possible Applications:
Horizontal Drill Bit Imaging, CDP Mult.
Reservoir Monitoring, Mars/Sun Seismology
3. Limitations:
Virtual Multiples
Coherent Noise
Reflectivity Imaging > Source Imaging
N Traces N 2 Correlograms
Acknowledgements
Thanks for support of UTAM sponsors.
Thank J. Rickett and J. Claerbout for
fruitful discussions.
Reduced-Time Migration
Shift Traces by
R1 Traveltime
Mitigate Src-Rec
Statics
m(x)=
d(x, t sx + t gx - t red. )
R1
R2
Interference Pattern
Phase Difference
Phase of Rays with Common Path Cancels
We only “see” Phase Difference
Outline
• Interferometric Principle: Phase Differences
• Passive Seismic Data: Ghost Reflection Imaging
• Synthetic Data Results
• CDP Multiple Data: Ghost Reflection Imaging
• Synthetic Data Results
• Source Imaging & Transmission PS Imaging
• Summary
Raw Seismograms
6.0
Time (s)
0
-6.0
0.8
Four-Layer Sand Channel Model
1.5
Depth (m)
0
-1.5
2100
0
Midpoint (m)
2100
Outline
• Interferometric Principle: Phase Differences
• Passive Seismic Data: Ghost Reflection Imaging
• Synthetic Data Results
Outline
• Interferometric Principle: Phase Differences
• Passive Seismic Data: Ghost Reflection Imaging
• Synthetic Data Results
• CDP Multiple Data: Ghost Reflection Imaging
Outline
• Interferometric Principle: Phase Differences
• Passive Seismic Data: Ghost Reflection Imaging
• Synthetic Data Results
• CDP Multiple Data: Ghost Reflection Imaging
• Synthetic Data Results
Outline
• Interferometric Principle: Phase Differences
• Passive Seismic Data: Ghost Reflection Imaging
• Synthetic Data Results
• CDP Multiple Data: Ghost Reflection Imaging
• Synthetic Data Results
• Source Imaging & Transmission PS Imaging
Outline
• Interferometric Principle: Phase Differences
• F.S. CDP Multiple Migration
IVSPWD
?
?
F.S. CDP Multiples
?
Outline
• Interferometric Principle: Phase Differences
• Locating Hydro-Fractures in EOR
IVSPWD
?
?
Hydro-Frac
?
F.S. CDP Multiples
?
Outline
• Interferometric Principle: Phase Differences
• PS Transmission Migration
IVSPWD
?
F.S. CDP Multiples
?
?
Hydro-Frac
PS Transmission
Migration
S
P
?
?
Outline
• Interferometric Principle: Phase Differences
• Passive Seismic Data: Ghost Reflection Imaging
IVSPWD
?
?
?
Outline
• Interferometric Principle: Phase Differences
• Locating Hydro-Fractures in EOR
IVSPWD
?
?
Hydro-Frac
?
F.S. CDP Multiples
?
Outline
• Interferometric Principle: Phase Differences
• Locating Hydro-Fractures in EOR
IVSPWD
?
?
F.S. CDP Multiples
?
Outline
• Interferometric Principle: Phase Differences
• PS Transmission Migration
IVSPWD
?
?
Hydro-Frac
?
F.S. CDP Multiples
?
Outline
• Interferometric Principle: Phase Differences
• PS Transmission Migration
IVSPWD
?
F.S. CDP Multiples
?
?
Hydro-Frac
PS Transmission
Migration
S
P
?
?
Crosscorrelogram R*G Migration
1. Construct M pseudo-shot gathers
(g, t
)
M
G
R*G
R
R*R
2. Migrate psuedo-shot gathers by sum M, g
m(x) =
M
g
(g, tgx + tMx )
M
shifted time
Outline
• Interferometric Principle: Phase Differences
• F.S. CDP Multiple Migration
IVSPWD
?
?
Outline
• Interferometric Principle: Phase Differences
•• Passive
F.S. CDP
Seismic
Multiple
Data:
Migration
Ghost Reflection Imaging
IVSPWD
?
?
F.S. CDP Multiples
?
Master
Ghost
G
D
Direct
Specular
Ray
Ghost
D*G
D*D
Direct
Crosscorrelogram R*G Migration
1. Construct N pseudo-shot gathers
(g, t
N
M
P
2. Migrate psuedo-shot gathers by sum N, g
m(x) =
N
g
(g, tgx + tNx )
N
shifted time
)
70 Raw Seismograms
6.0
Time (s)
0
0.8
-6.0
4-Layer Model
1.5
Depth (m)
0
-1.5
2100
0
Midpoint (m)
2100
70 Raw Seismograms
6.0
0
Time (s)
R
G
0.8
-6.0
4-Layer Model
1.5
Depth (m)
0
-1.5
2100
0
Midpoint (m)
2100
70 Raw Seismograms
6.0
Time (s)
0
0.8
-6.0
Correlogram Migration Image
1.5
Ghosts Imaged
Correctly
Depth (m)
0
Others Imaged
-1.5
Incorrectly
2100
0
Midpoint (m)
2100
Raw Seismograms
6.0
Time (s)
00
0.8
0.8
-6.0
Four-Layer Sand Channel Model
1.5
Depth (m)
00
-1.5
2100
0
Midpoint (m)
2100
Raw Seismograms
6.0
Time (s)
0
0.8
-6.0
Migration Image: 1-s Stack
1.5
Depth (m)
0
-1.5
2100
0
Midpoint (m)
2100
70 Raw Seismograms
6.0
Time (s)
0
0.8
-6.0
Migration Image: 50 1-s Stacks
1.5
Depth (m)
0
-1.5
2100
0
Midpoint (m)
2100