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
Gerard T. Schuster
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
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
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 has kinematics ofGhost
primary
reflection
x Direct
Direct x Direct
1
}2
t
M
Kirchhoff Migrate psuedo-shot gathers
m(x) =
M
g
(g, tgx + tMx )
M
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
Geological Model
0
0
X (m)
4
Depth (m)
V1
V2
V3
V4
V5
3
V6
Velocity Model (J. Yu)
X(km)
Depth(km)
0
0
4
0
0
X(km)
3.5
3.5
2.0
2.0
3
3
Interval Velocity
4
RMS Velocity
Autocorrelogram
Shot Gather
200
0
Time (s)
Traces
Time (s)
0
1
4
4
1
CSG 10
Traces
200
Ghost Autocorrelogram Depth
Migration
X (km)
1.6
X (km)
2.1
2.1
0
Depth (km)
0
1.6
2.8
2.8
With primary+ghost
Without ghost
Acquisition Survey
East (kft)
0
0
Drill bit
Well Rig
-5
Depth (kft)
0
10
4.5
Raw CGR 96
1
Trace #
Proc. CGR 96
10
1
Time (s)
0
7
5-40 Hz
Trace #
10
Acquisition Survey Map
Well Rig
North (ft)
0
Drill bit
-5000
0
1500
3000
East (ft)
4500
SP
1255
1235
1215
1.0
Drill
Time (s)
hole
2.0
3.0
Ghost Autocorrelogram Image(Corr. window=8 s)
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
Ghostx Primary has kinematics
x Primary
of primary
ref.
Ghost
Primary x Primary
}2
1
t
Kirchhoff Migrate psuedo-shot gathers
m(x) =
g
(g, tgx + tMx )
M
3
Caution: Ghost x Primary = R
Nine-Layered Model (J. Sheng)
Kirchhoff
Image
Model
Crosscorrelogram image
0
0.6
artifacts
1.2
1.8
2.4
3.0
0
Distance (km)
3.0
0
Distance (km)
3.0
Nine-Layered Model
Product Image
=Kirch*correl.
Kirchhoff Image
0
0.6
artifacts
1.2
1.8
2.4
3.0
0
Distance (km)
3.0
0
Distance (km)
3.0
SEG/EAGE Salt Model
0
0.6
1.2
1.8
2.4
3.0
3.6
0
5.0
10.0
Distance (km)
15.0
Crosscorrelogram Image
0
0.6
1.2
1.8
2.4
3.0
3.6
0
5.0
10.0
Distance (km)
15.0
Kirchhoff Image
0
0.6
1.2
1.8
2.4
3.0
3.6
0
5.0
10.0
Distance (km)
15.0
Product Image
0
0.6
1.2
1.8
2.4
3.0
3.6
0
5.0
10.0
Distance (km)
15.0
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
Crosswell Model (D. Sheley)
0
Vp /Vs = 1.5
Source = 1500 Hz
ds = 2 m
dg = 2 m
Well Separation
= 100 m
5500 m/s
5000 m/s
114
0
Offset (m)
114
Synthetic Data
Original Data
Shifted Muted Data
0
0
P
S
PS
PS
SP
114
SP
114
20
Time (ms)
35
2
Time (ms) 8
Conventional PS
Transmission Migration
True Velocity
0
+ 10 % Velocity
114
0
Offset (m)
100
0
Offset (m)
100
Reduced-Time PS Migration
True Velocity
0
+ 10 % Velocity
114
0
Offset (m)
100
0
Offset (m)
100
Comparison +10% Velocity
Conventional PS
0
Interferometric PS
114
0
Offset (m)
100
0
Offset (m)
100
Kidd Creek Crosswell
0
Receiver
Well
Source
Well
7.0
6.0
40
5.0
60
0
Offset (m)
50
km/sec
Depth (m)
20
Data Problems
• Time Delay = 3 ms ?
• Well Location
• Velocity Model
Depth (m)
Time
Shifted
CRG
0
20
40
60
0
Time (ms)
6
Conventional PS
0
20
60
0
Offset (m)
50
Reduced-Time
Conventional
PS
0
20
60
0
Offset (m)
50 0
Offset (m)
50
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
Earthquake Rec.-Function/Ghost Imaging
3. Limitations:
Virtual Multiples
Coherent Noise
Reflectivity Imaging > Source Imaging
N Traces N 2 Correlograms
Current & Future Work
1. Reduce Coherent Noise and Virtual Multiples
2. Earthquake Rec. Funct. & Ghost Imaging
3. Reservoir Monitoring with CDP Data
4. Passive Data Experiment
Reduced-Time Migration
Shift Traces by
R1 Traveltime
Mitigate Src-Rec
Statics
m(x)=
d(x, t sx + t gx - t red. )
R1
R2
Acknowledgements
Thanks for support of UTAM sponsors.
Thank J. Rickett and J. Claerbout for
fruitful discussions.
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
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
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
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
)
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
)