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Overview ofOverview of Utah Tomography and Utah Tomography and
Modeling/MigrationModeling/Migration (UTAM) (UTAM)
Chaiwoot B., T. Crosby, G. Jiang, R. He, G. Schuster, Chaiwoot B., T. Crosby, G. Jiang, R. He, G. Schuster,
J. Sheng, J. Yu, M. Zhou and Xiang Xiao J. Sheng, J. Yu, M. Zhou and Xiang Xiao
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2004 UTAM Consortium2004 UTAM ConsortiumAramcoAramco
BP-AmocoBP-Amoco
BGPBGP
GeotomoGeotomo
Chevron-TexacoChevron-Texaco
Conoco-PhillipsConoco-Phillips
IMPIMP
INCOINCO
SisimageSisimage
UnocalUnocal
VeritasVeritas
Western-GecoWestern-Geco
($24 K/year)($24 K/year)
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• Started 1988Started 1988
• 10-18 sponsors/year10-18 sponsors/year
• $24,000/year membership$24,000/year membership
• BenefitsBenefits: : Yearly meeting: Feb. 3-4Yearly meeting: Feb. 3-4Annual+midyr ReportAnnual+midyr ReportSoftwareSoftware
• Goal: Innovative Imaging/ModelingGoal: Innovative Imaging/Modeling
UTAMUTAM
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Jianhua Yu, Min Zhou
Gerard T. Schuster
University of Utah
Interferometric Imaging below SaltAnd Overburden
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Outline Outline
Motivation
Interferometric Imaging
Synthetic Data
Conclusions
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Outline Outline
Motivation
Interferometric Imaging
Synthetic & Field Data
Conclusions
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Problems with VSP or CDP Salt Problems with VSP or CDP Salt Imaging Quality? Imaging Quality?
Salt v(x,y,z) not knownSalt v(x,y,z) not known
Static errorsStatic errors??
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Outline Outline
Motivation
Interferometric Imaging
Synthetic & Field Data
Conclusions
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Uninteresting Part of MediumUninteresting Part of Medium
How do you remove kinematic effects of propagatingHow do you remove kinematic effects of propagatingthrough unintersting parts of medium?through unintersting parts of medium?
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Pick Direct Arrival Time T and shift allPick Direct Arrival Time T and shift allTraces by T Traces by T MM
MM
{{MMTT
MM
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MM
{{MMTT
Shifting Traces Removes Kinematic EffectsShifting Traces Removes Kinematic EffectsOf Propagating through Uninteresting Parts of MediumOf Propagating through Uninteresting Parts of Medium
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MM
Shifting Traces Removes Kinematic EffectsShifting Traces Removes Kinematic EffectsOf Propagating through Uninteresting Parts of MediumOf Propagating through Uninteresting Parts of Medium
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MM
Shifting Traces Removes Kinematic EffectsShifting Traces Removes Kinematic EffectsOf Propagating through Uninteresting Parts of Medium.Of Propagating through Uninteresting Parts of Medium.
..
MM MM
m(x) = (g, t + t )m(x) = (g, t + t )
gxgx gg MMxxgxgx
Kirchhoff Migrate psuedo-shot gathersKirchhoff Migrate psuedo-shot gathersSource Moved to DepthSource Moved to Depth
Can replace time-shifted traces by crosscorrelogramsCan replace time-shifted traces by crosscorrelograms
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MM
MM MM
m(x) = (g, t + t )m(x) = (g, t + t )
gxgx gg MMxxgxgx
Kirchhoff Migrate psuedo-shot gathersKirchhoff Migrate psuedo-shot gathers
Can replace time-shifted traces by crosscorrelogramsCan replace time-shifted traces by crosscorrelograms
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MM
MM MM
m(x) = (g, t + t )m(x) = (g, t + t )
gxgx gg MMxxgxgx
Kirchhoff Migrate psuedo-shot gathersKirchhoff Migrate psuedo-shot gathers
Can replace time-shifted traces by crosscorrelogramsCan replace time-shifted traces by crosscorrelograms
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MM
MM MM
m(x) = (g, t + t )m(x) = (g, t + t )
gxgx gg MMxxgxgx
Kirchhoff Migrate psuedo-shot gathersKirchhoff Migrate psuedo-shot gathers
Can replace time-shifted traces by crosscorrelogramsCan replace time-shifted traces by crosscorrelograms
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MM
MM MM
m(x) = (g, t + t )m(x) = (g, t + t )
gxgx gg MMxxgxgx
Kirchhoff Migrate psuedo-shot gathersKirchhoff Migrate psuedo-shot gathers
Can replace time-shifted traces by crosscorrelogramsCan replace time-shifted traces by crosscorrelograms
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MM
MM MM
m(x) = (g, t + t )m(x) = (g, t + t )
gxgx gg MMxxgxgx
Kirchhoff Migrate psuedo-shot gathersKirchhoff Migrate psuedo-shot gathers
Can replace time-shifted traces by crosscorrelogramsCan replace time-shifted traces by crosscorrelograms
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MM
MM MM
m(x) = (g, t + t )m(x) = (g, t + t )
gxgx gg MMxxgxgx
Kirchhoff Migrate psuedo-shot gathersKirchhoff Migrate psuedo-shot gathers
Can replace time-shifted traces by crosscorrelogramsCan replace time-shifted traces by crosscorrelograms
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Interferometric SummaryInterferometric SummaryEliminates source statics and Eliminates source statics and uninteresting parts of the medium.uninteresting parts of the medium.
Lower source to be near target.Lower source to be near target.
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Interferometric SummaryInterferometric SummaryEliminates source+Eliminates source+recrec statics and statics and uninteresting parts of the medium.uninteresting parts of the medium.
Reference layerReference layer
Lower source+Lower source+recrec. to be near target.. to be near target.
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Outline Outline
Motivation
Interferometric Imaging
Synthetic CDP Data & Field Data
Conclusions
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Shots: 280Shots: 280
Shot interval: 10 mShot interval: 10 m
Receivers: 300Receivers: 300
Receiver interval: 10 mReceiver interval: 10 m
Temporal interval:1msTemporal interval:1ms
X (km)X (km)00 3300
1.81.8
De
pth
(k
m)
De
pth
(k
m)
Salt modelSalt model
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X (km)X (km)00 3300
1.81.8
De
pth
(k
m)
De
pth
(k
m)
True velocity modelTrue velocity model
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X (km)X (km)00 3300
33
Tim
e (
s)T
ime
(s)
CSG 100CSG 100
Pick TraveltimePick TraveltimeSubsalt ReferenceSubsalt ReferenceReflectionReflection
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X (km)X (km)00 3300
1.81.8
De
pth
(k
m)
De
pth
(k
m)
Kirmig with inaccurate salt dome boundaryKirmig with inaccurate salt dome boundary
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X (km)X (km)00 3300
1.81.8
De
pth
(k
m)
De
pth
(k
m)
RT migration with inaccurate salt dome RT migration with inaccurate salt dome boundaryboundary
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X (km)X (km)00 3300
1.81.8
De
pth
(k
m)
De
pth
(k
m)
Standard migStandard mig
Correct velocityCorrect velocity
X (km)X (km)00 33 X (km)X (km)00 33
Standard migStandard mig
Incorrect Incorrect velocityvelocity
RT migRT mig
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Outline Outline
Motivation
Interferometric Imaging
Synthetic HSP Data & Field Data
Conclusions
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0 km0 km5 km5 km
0 km0 km
5 km5 km
Mig. Image+Corr. Vel.Mig. Image+Corr. Vel.
0 km0 km
1.2 s1.2 s
0 km0 km
1.2 km1.2 km
0 km0 km
1.2 km1.2 km
0 km0 km
1.2 km1.2 km
0 km0 km 1.2 km1.2 km 0 km0 km 1.2 km1.2 km
HSP Shot GatherHSP Shot GatherSalt ModelSalt Model
HSP Interferometric ImagingHSP Interferometric Imaging
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0 km0 km5 km5 km
0 km0 km
5 km5 km
Mig. Image+Corr. Vel.Mig. Image+Corr. Vel.
HSP Interferometric ImagingHSP Interferometric Imaging
0 km0 km
1.2 s1.2 s
0 km0 km
1.2 km1.2 km
0 km0 km
1.2 km1.2 km
0 km0 km
1.2 km1.2 km
0 km0 km 1.2 km1.2 km 0 km0 km 1.2 km1.2 km
HSP Shot GatherHSP Shot GatherSalt ModelSalt Model
HSP Interferometric ImagingHSP Interferometric Imaging
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0 km0 km5 km5 km
0 km0 km
5 km5 km
Mig. Image+Corr. Vel.Mig. Image+Corr. Vel.
0 km0 km
1.2 s1.2 s
0 km0 km
1.2 km1.2 km
0 km0 km
1.2 km1.2 km
0 km0 km
1.2 km1.2 km
0 km0 km 1.2 km1.2 km 0 km0 km 1.2 km1.2 km
Salt ModelSalt Model HSP Shot GatherHSP Shot Gather
HSP ImageHSP Image
HSP Interferometric ImagingHSP Interferometric Imaging
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0 km0 km5 km5 km
0 km0 km
5 km5 km
Mig. Image+Corr. Vel.Mig. Image+Corr. Vel.
0 km0 km
1.2 s1.2 s
0 km0 km
1.2 km1.2 km
0 km0 km
1.2 km1.2 km
0 km0 km
1.2 km1.2 km
0 km0 km 1.2 km1.2 km 0 km0 km 1.2 km1.2 km
Salt ModelSalt Model HSP Shot GatherHSP Shot Gather
HSP ImageHSP Image SWI-HSP ImageSWI-HSP Image
GarbageGarbage
HSP Interferometric ImagingHSP Interferometric Imaging
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0 km0 km5 km5 km
0 km0 km
5 km5 km
Mig. Image+Corr. Vel.Mig. Image+Corr. Vel.
0 km0 km
1.2 s1.2 s
0 km0 km
1.2 km1.2 km
0 km0 km
1.2 km1.2 km
0 km0 km
1.2 km1.2 km
0 km0 km 1.2 km1.2 km 0 km0 km 1.2 km1.2 km
Salt ModelSalt Model HSP Shot GatherHSP Shot Gather
HSP ImageHSP Image SWI-HSP ImageSWI-HSP Image
GarbageGarbage
No Need for VNo Need for V
HSP Interferometric ImagingHSP Interferometric Imaging
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Outline Outline
Motivation
Interferometric Imaging
Synthetic VSP Data & Field Data
Conclusions
Page 36
VSP DataVSP Data0 km0 km
2 km2 km
0 km 3 km0 km 3 km
Image Below Salt WithoutImage Below Salt WithoutKnowing Salt VelocityKnowing Salt Velocity
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X (m) 14001000
950
1950
Dep
th (
m)
Interferometric ImageInterferometric Image
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Well
2
0D
epth
(k
m)
0 3X (km)
SEG/EAGE Model
256 Sources
V = 1.5 - 3.0 km/s
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Tim
e (s
)
3
00 2.4X (km) 1.4 2.4X (km)
Xcross 60CRG 60
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2.0
0.5
Dep
th (
km
)
0.5 2.5X (km)
Kirchh Mig (45) Xcorr Mig (45) Xcorr. Mig(15’)
2.52.5 0.5 0.5
Page 41
Outline Outline
Motivation
Interferometric Imaging
Synthetic VSP Data & Field Data
Conclusions
Page 42
Tim
e (s
)
0.3
030 900Depth (ft)
Raw Data(CRG15)
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Tim
e (s
)
0.3
030 900Depth (ft)
Ghosts
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Dep
th (
ft)
1300
2000 400X (ft) 0 400X (ft)
Standard mig Xcorr. mig
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SUMMARYSUMMARY• Interferometric Imaging: Kinematically Interferometric Imaging: Kinematically
equivalent to sources-receivers below datumequivalent to sources-receivers below datum
• Interferometric TomographyInterferometric Tomography
• True wave equation statics w/o V(x,y,z)True wave equation statics w/o V(x,y,z)
• HSP, VSP and CDP dataHSP, VSP and CDP data
Salt + OverburdenSalt + Overburden
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SUMMARYSUMMARY• Interferometric Imaging: Kinematically Interferometric Imaging: Kinematically
equivalent to sources-receivers below datumequivalent to sources-receivers below datum
• Interferometric TomographyInterferometric Tomography
• True wave equation statics w/o V(x,y,z)True wave equation statics w/o V(x,y,z)
• HSP, VSP and CDP dataHSP, VSP and CDP data
Salt + OverburdenSalt + Overburden
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Crosscorrelogram Migration Conclusions Crosscorrelogram Migration Conclusions
Eliminate the static errors in the well
No need to know source (RVSP) or receiver location (VSP)
Half sensitivity to velocity migration errors than mult. migration by “mirrors”.
Increased illumination coverage in the VSP image. VSP ->CDP
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Conclusions Conclusions Loss of some lateral resolution?
Be careful about virtual multiple
Xcorr
Narrow Angle
Kirchhoff
Wide Angle
vs
Ghost is weaker than primaryExtra summation compared to KM
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Outline Outline
Motivation
Crosscorrelation Migration
SEG/EAGE Model
2-D RVSP Field Data
Conclusions
Page 50
Well
2
0D
epth
(k
m)
0 3X (km)
SEG/EAGE Model
256 Sources
V = 1.5 - 3.0 km/s
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Well
2
0D
epth
(k
m)
0 3X (km)
Receiver interval: 10 m
Receiver depth range: 0.1 -1 km
Receiver number: 91
Sample interval: 1 ms
Recording length: 3 s
Well location: (1.5 km, 0 km)
Source interval: 10 m
Source number: 256
Acquisition Parameters:
1 km
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Tim
e (s
)
3
00.2 0.9Depth (km)
CSG 160
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Tim
e (s
)
3
00.2 0.9Depth (km)
Ghosts (CSG 160)
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Tim
e (s
)
3
00 2.4X (km) 1.4 2.4X (km)
Xcross 60CRG 60
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2.0
0.5
Dep
th (
km
)
0.5 2.5X (km)
Kirchh Mig (45) Xcorr Mig (45) Xcorr. Mig(15’)
2.52.5 0.5 0.5
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Sta
tic
erro
rs (
ms)
-50
500 900Well Depth (m)
Raw Data
Static Errors at Well
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2.0
0.5
Dep
th (
km
)
0.5
Kirchhoff MigrationStatic Error: 0
X (km)
Static Error: 25 ms
2.5
Static Error: 50ms
2.52.5 0.5 0.5
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2.0
0.5
Dep
th (
km
)
0.5
Crosscorrelation MigrationStatic Error: 0
X (km)
Static Error: 25ms
2.5
Static Error: 50 ms
2.52.5 0.5 0.5
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Velocity ModelVelocity Model Primary vs Multiple ImagePrimary vs Multiple Image
00
111100 1616 00 1616X (km)X (km) X (km)X (km)
Dep
th (k
m)
Dep
th (k
m)
Page 60
Contents Contents
Motivation
Crosscorrelation Imaging Condition
SEG/EAGE Model
2-D RVSP Field Data
Conclusions
Page 61
Tim
e (s
)
0.3
030 900Depth (ft)
Raw Data(CRG15)
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Tim
e (s
)
0.3
030 900Depth (ft)
Ghosts
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5 24Trace No.
Tim
e (s
)
1.2
0.2 xcorr data (muted)
Tim
e (s
)
1.4
0.55 24Trace No.
Field Data (CSG 25)
Raw data (muted)
Master trace Master trace
Page 64
Dep
th (
ft)
1300
2000 400X (ft) 0 400X (ft)
Standard mig Xcorr. mig
Page 65
Dep
th (
ft)
1100
0
Standard Well data Xcorr.
Exxon Data
Page 66
Outline Outline
Motivation
Crosscorrelation Migration
SEG/EAGE Model
2-D RVSP Field Data
Conclusions
Page 67
Crosscorrelogram Migration Conclusions Crosscorrelogram Migration Conclusions
Eliminate the static errors in the well
No need to know source (RVSP) or receiver location (VSP)
Half sensitivity to velocity migration errors than mult. migration by “mirrors”.
Increased illumination coverage in the VSP image. VSP ->CDP
Page 68
Conclusions Conclusions Loss of some lateral resolution?
Be careful about virtual multiple
Xcorr
Narrow Angle
Kirchhoff
Wide Angle
vs
Ghost is weaker than primaryExtra summation compared to KM
Page 69
AcknowledgmentsAcknowledgments
UTAM sponsorsUTAM sponsors
Exxon for 2-D field dataExxon for 2-D field data
J. Claerbout + J. RickettJ. Claerbout + J. Rickett
II evolved from daylight II evolved from daylight imagingimaging
Page 70
Dep
th (
ft)
1300
2000 400X (ft) 0 400X (ft)
Standard mig Xcorr. mig
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Geological ModelGeological Model0 4
0
3
Dep
th(k
m)
X(km)
(2001)(2001)
Page 72
Migration Result Using Crosscorrelation ImagingMigration Result Using Crosscorrelation Imaging
1.6
0
2.2
Tim
e (s
)
2.1X (km)
Too simple?
Widen illumination?
If there are static errors in well?
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Why Use Crosscorrelation Why Use Crosscorrelation Migration?Migration?
Widen the illumination coverage in the VSP image
VSP geometryEquivalent surface geometry
Xcorr
Page 74
Seismic Ghost ReflectionSeismic Ghost Reflection
DirectDirect
GhostGhost
??Find R(x,z) but not know source locationFind R(x,z) but not know source location
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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
Page 76
WellWell
SourceSource
ReceiverReceiver
Primary
Direct Wave
Ghost
RVSP
Page 77
x
g
s xg
xg ' sg
'sg
Ghost Reflection Imaging ConditionGhost Reflection Imaging Condition:
'g
xgxgsg
''
sg
'sg
Page 78
x
g
s xg
xg ' sg
'sg
After Crosscorrelation of Two Traces at After Crosscorrelation of Two Traces at Locations g & g’Locations g & g’
'g
xgxgsg
''
sg
'sg
'sg
Page 79
x
g
s xg
xg '
After Crosscorrelation of Two Traces at After Crosscorrelation of Two Traces at Locations g & g’Locations g & g’
'g
xgxg
'
sg
'sg
Page 80
x
g
s
After Crosscorrelation of Two Traces at After Crosscorrelation of Two Traces at Locations g & g’Locations g & g’
'g
xg
xg '
xgxg
'
sg
'sg
Page 81
Recall Green’s TheoremRecall Green’s TheoremEvery Surface Point = Source PointEvery Surface Point = Source Point
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xgxgsgg
''''
Why is there insensitivity to static errors in the well?
ssgsg
'''
xgxgxcorrg
''
s
g’ g
xStatic errors
''sg
xgxgsgg
''''
Page 83
Crosscorrelogram MigrationCrosscorrelogram Migration
''')( )()( dgdgxgxgggDCorr xm
Migrated ImageMigrated Image
Crosscorrelograms
Crosscorrelation Crosscorrelation Imaging ConditionImaging Condition
Page 84
Dep
th (
ft)
1100
0
Well data Xcorr. Migration
Field Data
Page 85
Dep
th (
ft)
1100
0
Well data Standard Migration
Exxon Data
Page 86
Above SourceAbove SourceImagingImaging {{
Wider CoverageWider Coverage
VSPVSP
Interferometric SummaryInterferometric SummaryWider, taller coverage. Eliminates Wider, taller coverage. Eliminates well statics and uninteresting parts of well statics and uninteresting parts of the medium.the medium.
MM MM
m(x) = (g, t + t )m(x) = (g, t + t )
gxgx gg MMxxgxgx
Kirchhoff Migrate psuedo-shot gathersKirchhoff Migrate psuedo-shot gathers
Page 87
Shifting Traces Removes Kinematic EffectsShifting Traces Removes Kinematic EffectsOf Propagating through Uninteresting Parts of Medium.Of Propagating through Uninteresting Parts of Medium.
..
MM
MM MM
m(x) = (g, t + t )m(x) = (g, t + t )
gxgx gg MMxxgxgx
Kirchhoff Migrate psuedo-shot gathersKirchhoff Migrate psuedo-shot gathers
gg
Source Moved to DepthSource Moved to Depth
Can replace time-shifted traces by crosscorrelogramsCan replace time-shifted traces by crosscorrelograms
Page 88
m
Distance (km)Distance (km)00 1010
CDP Interferometric Imaging CDP Interferometric Imaging D
epth
(km
)D
epth
(km
)
1010
Distance (km)Distance (km)00 1010
00
Distance (km)Distance (km)00 1010
ModelModelKM image with KM image with
Incorrect velocityIncorrect velocitykm/skm/s
Datuming with Datuming with ReflectionsReflectionss g
3.23.2
3.03.0
2.82.8
Page 89
m
Distance (km)Distance (km)00 1010
CDP Interferometric Imaging CDP Interferometric Imaging D
epth
(km
)D
epth
(km
)
1010
Distance (km)Distance (km)00 1010
00
Distance (km)Distance (km)00 1010
ModelModelKM image with KM image with
Incorrect velocityIncorrect velocitykm/skm/s
Datuming with Datuming with ReflectionsReflectionss g
3.23.2
3.03.0
2.82.8
Page 90
m
Distance (km)Distance (km)00 1010
CDP Interferometric Imaging CDP Interferometric Imaging D
epth
(km
)D
epth
(km
)
1010
Distance (km)Distance (km)00 1010
00
Distance (km)Distance (km)00 1010
ModelModelKM image with KM image with
Incorrect velocityIncorrect velocitykm/skm/s
Datuming with Datuming with ReflectionsReflectionss g
3.23.2
3.03.0
2.82.8