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1.51.5
-1.5-1.5
6.06.0
-6.0-6.0
21002100
Dep
th (
m)
Dep
th (
m)
Tim
e (s
)T
ime
(s)
Raw SeismogramsRaw Seismograms
0 21000 2100
Four-Layer Sand Channel ModelFour-Layer Sand Channel Model
00
00
0.80.8
Midpoint (m)Midpoint (m)
Interferometric Seismic Interferometric Seismic ImagingImaging
Jianhua Yu & Gerard T. SchusterJianhua Yu & Gerard T. Schuster
University of UtahUniversity of Utah
OutlineOutline
Passive data for IVSP while DrillingPassive data for IVSP while DrillingImaging of Free Surface CDP MultiplesImaging of Free Surface CDP Multiples
• Interferometric Principle: Interferometric Principle:
Time Diff. between Arrivals Structure Diff.Time Diff. between Arrivals Structure Diff.
• Interferometric Imaging Applications: Interferometric Imaging Applications:
Claerbout,Claerbout,Katz, 70’sKatz, 70’sxxxx
Earthquake 1900’sEarthquake 1900’s
xxxxUtah+LLNL 1997Utah+LLNL 1997
MigrateMigrate
Claerbout,Claerbout,Rickett 1999Rickett 1999xxyy
xxyyMigrateMigrate
Arbitrary Unknown Src V(z) V(x,y,z) Arbitrary Unknown Src V(z) V(x,y,z) W(t) LocationW(t) Location
NONO YESYES YESYES YESYES
NONO
YESYES YESYES YESYES
YES/YES/NONO YESYES NO?NO?
NONO YESYES YESYES
YES/YES/NONO YESYESNONO
YESYES
YESYES
YESYES
SELECTIVE HISTORY PASSIVE IMAGINGSELECTIVE HISTORY PASSIVE IMAGING
ValidityValidity
Interference PatternInterference Pattern
Optical LensOptical Lens
LASERLASER
Optical LensOptical LensOptical LensOptical Lens
t
Interference PatternInterference Pattern
Optical LensOptical Lenss s
tLASERLASERLens Deformation Time DifferencesLens Deformation Time Differences
OutlineOutline
Passive data for IVSP while DrillingPassive data for IVSP while Drilling
• Interferometric Principle: Interferometric Principle:
Time Diff. between Arrivals Structure Diff.Time Diff. between Arrivals Structure Diff.
• Interferometric Imaging Applications: Interferometric Imaging Applications:
Seismic Ghost ReflectionSeismic Ghost Reflection
DirectDirect
GhostGhost
??Find R(x,z) but not know source locationFind R(x,z) but not know source location
DirectDirect
GhostGhost
1 2DirectDirect xx
DirectDirectxx
MasterMasterSeismic Ghost ReflectionSeismic Ghost ReflectionSeismic Interferogram: Correlate TracesSeismic Interferogram: Correlate Traces
t}
MM
m(x) = (g, t + t )m(x) = (g, t + t )
gxgx gg MMxxgxgxMM
Kirchhoff Migrate psuedo-shot gathersKirchhoff Migrate psuedo-shot gathers
GhostGhost Direct Direct has kinematics of primary reflectionhas kinematics of primary reflectionxx
MM
Source Geophone
Bit Position?Bit Position?
Problems in RVSPWDProblems in RVSPWD
Pilot signal?
Wavelet ?
Problems with Drill-bit and Problems with Drill-bit and RVSP DataRVSP Data
No source waveletNo source wavelet
No source initiation timeNo source initiation time
Not easy to get pilot signal in Not easy to get pilot signal in deviated welldeviated well and horizontal well
Static shift errors may existStatic shift errors may exist
Difficulty for separating primary Difficulty for separating primary and ghost waves from deviated and ghost waves from deviated or horizontal wellor horizontal well
Problems with Drill-bit and Problems with Drill-bit and RVSP DataRVSP Data
Solution Solution
Cross- or Auto-correlogram Cross- or Auto-correlogram MigrationMigration
Why do we use autocorrelation of seismic data rather than the seismogram ???
Strengths of Autocorrelogram Migration
No need to know initial time
No limits to deviated well
Reduce Static errors influence
No need
to know source wavelet
Weakness of Correlogram Migration
Virtual Multiples & Loss of Resolution
WellWell
Drill bitDrill bit
ReceiverReceiver
Primary
Direct Wave
Ghost
What is Joint Migration What is Joint Migration
What is Joint Migration What is Joint Migration
Final migration image
Ghost migration
Primary migration
Seismic Data
Horizontal Well ModelHorizontal Well Model
0
Dep
th (
m)
3
40X (m)
V1
V2
V4
V3
V5
V6
Shot GatherShot Gather
1 2000
4
Tim
e (s
)
CSG 10
1 2000
4
Tim
e (s
)
TracesTraces
AutocorrelogramAutocorrelogram
1.6 2.10
2.5
Dep
th (
km
)
X (km)1.6 2.1
X (km)
Standard migration Joint migration
Standard Migration with Joint Migration Standard Migration with Joint Migration ((3 CSGs3 CSGs))
SourceSource
1.6 2.10
2.0
Tim
e (s
)
X (km)1.6 2.1
X (km)
With only primary Joint auto. migration
Time Migration Results (Time Migration Results (39 CSGs39 CSGs))
SourceSource
00
00 4.54.5
-5-5
East (kft)East (kft)
North
(kft)
North
(kft)
Well Rig
10
Dep
th (
kft
)D
epth
(k
ft)
0
9188 ft
Offset=1135-4740 ft
Recording Length: 20 sRecording Length: 20 s
Sample Interval: 2 msSample Interval: 2 ms
Main Acquisition ParametersMain Acquisition Parameters
Main Processing StepsMain Processing Steps Trace editing and static shiftTrace editing and static shift
Frequency panel analysis and noise eliminationFrequency panel analysis and noise elimination
Velocity analysisVelocity analysis
Amplitude balance and energy normalizationAmplitude balance and energy normalization
Autocorrelograms, vertical stackingAutocorrelograms, vertical stacking
Joint migrating autocorelogramsutocorelograms
Acquisition Survey MapAcquisition Survey Map
Well Rig
3C Receivers
Drill bit
00
00 15001500 30003000 45004500-5000-5000
East (ft)East (ft)
Nor
th (
ft)
Nor
th (
ft)
Line ACC4
3.0
2.0
1.0T
ime
(s)
SP 1255 1235 1215
DrillDrill holehole
Joint Migration ( insert) and CDP SectionJoint Migration ( insert) and CDP Section
3.0
2.0
1.0T
ime
(s)
SP 1255 1235 1215
Primary Migration ( insert) and CDP SectionPrimary Migration ( insert) and CDP Section
DrillDrill holehole
3.0
2.0
1.0T
ime
(s)
SP 1255 1235 1215
DrillingDrilling holehole
Joint Migration ( insert) and CDP SectionJoint Migration ( insert) and CDP Section
JOINT
3.0
2.0
1.0T
ime
(s)
SP 1255 1235 1215
Primary Migration ( insert) and CDP SectionPrimary Migration ( insert) and CDP Section
DrillingDrilling holehole
Primary
SUMMARYSUMMARY
Need separating primary and multiple?Need separating primary and multiple? NO
Work for deviated or horizontal well ?Work for deviated or horizontal well ? YES
Reduce the influence of static errors ?Reduce the influence of static errors ? YES
Need pilot signal ?Need pilot signal ? NO
Need source wavelet and initial time ?Need source wavelet and initial time ? NO
Suppress coherent noise ?Suppress coherent noise ? YES
Amplitude fidelity ?Amplitude fidelity ? NO
Virtual Multiple ?Virtual Multiple ? YES
6.06.0
-6.0-6.0
Thanks to 1997-2002 UTAM sponsors Thanks to 1997-2002 UTAM sponsors and DOE.and DOE.
Thanks to Lew Katz and Fred Followill.Thanks to Lew Katz and Fred Followill.
PrimaryPrimaryGhostGhost
1 2
Free-Surface MultipleFree-Surface Multiple
PrimaryPrimaryGhostGhost
1 2
xxPrimaryPrimary
xx PrimaryPrimary
Seismic Interferogram: Correlate TracesSeismic Interferogram: Correlate Traces
Caution: Caution: GhostGhost xx Primary = RPrimary = R3
t}
m(x) = (g, t + t )m(x) = (g, t + t )
gxgx gg MMxxgxgxMM
Kirchhoff Migrate psuedo-shot gathersKirchhoff Migrate psuedo-shot gathers
GhostGhost Primary Primary has kinematics of primary ref.has kinematics of primary ref.xx
Nine-Layered Model (J. Sheng)Nine-Layered Model (J. Sheng)
00
0.60.6
1.21.2
1.81.8
3.03.0
Dep
th (
km
)D
epth
(k
m)
2.42.4
ModelModel Crosscorrelogram imageCrosscorrelogram image
Distance (km)Distance (km)0 3.0 Distance (km)Distance (km)0 3.0
artifactsartifacts
Kirchhoff ImageKirchhoff Image
Nine-Layered ModelNine-Layered ModelKirchhoff ImageKirchhoff Image
Product ImageProduct Image=Kirch*correl.=Kirch*correl.
00
0.60.6
1.21.2
1.81.8
3.03.0
Dep
th (
km
)D
epth
(k
m)
2.42.4
Distance (km)Distance (km)0 3.0 Distance (km)Distance (km)0 3.0
artifactsartifacts
SEG/EAGE Salt ModelSEG/EAGE Salt Model00
0.60.6
1.21.2
1.81.8
2.42.4
Dep
th (
km
)D
epth
(k
m)
3.03.0
3.63.6
0 5.0 10.0 15.00 5.0 10.0 15.0Distance (km)Distance (km)
Crosscorrelogram ImageCrosscorrelogram Image00
0.60.6
1.21.2
1.81.8
2.42.4
Dep
th (
km
)D
epth
(k
m)
3.03.0
3.63.6
0 5.0 10.0 15.00 5.0 10.0 15.0Distance (km)Distance (km)
Kirchhoff ImageKirchhoff Image00
0.60.6
1.21.2
1.81.8
2.42.4
Dep
th (
km
)D
epth
(k
m)
3.03.0
3.63.6
0 5.0 10.0 15.00 5.0 10.0 15.0Distance (km)Distance (km)
Product ImageProduct Image00
0.60.6
1.21.2
1.81.8
2.42.4
Dep
th (
km
)D
epth
(k
m)
3.03.0
3.63.6
0 5.0 10.0 15.00 5.0 10.0 15.0Distance (km)Distance (km)