vsp->swp interferometry
DESCRIPTION
VSP->SWP Interferometry. Redatum sources below overburden. Local VSP migration. 3x3 Classification Matrix. SSP. VSP. SWP. SSP. SSP. SSP. SSP. VSP. SSP. SWP. VSP. VSP. SSP. VSP. VSP. VSP. SWP. SSP. SWP. SWP. SWP. VSP. SWP. SWP. Motivation. - PowerPoint PPT PresentationTRANSCRIPT
VSP->SWP InterferometryVSP->SWP Interferometry
Redatum sources below overburdenRedatum sources below overburden
Local VSP migrationLocal VSP migration
3x3 Classification Matrix3x3 Classification Matrix
SSPSSP VSPVSP SWPSWP
VSPVSP
SSPSSP
SWPSWP
SSPSSP SSPSSP SSPSSP SSPSSPVSPVSP SWPSWP
VSPVSP VSPVSP VSPVSP
SWPSWP SWPSWP SWPSWP
VSPVSP
SWPSWP
SWPSWP
VSPVSP
SSPSSP
SSPSSP
Problem:Problem: Overburden+statics defocus VSP migration Overburden+statics defocus VSP migration
Redatum sources below overburdenRedatum sources below overburden
Local VSP migrationLocal VSP migration
Solution:Solution: VSP -> SWP Transform VSP -> SWP Transform
MotivationMotivation
• MotivationMotivation
• Interferometry TheoryInterferometry Theory
• Numerical ExamplesNumerical Examples
• ConclusionConclusion
OutlineOutline
AA
BB
xx
Reciprocity Correlation EquationReciprocity Correlation Equation
==kG(kG(BB||xx))* * G(G(AA||xx) )
SS00
VSPVSP{
Im G(Im G(BB||AA))
SWPSWP{
Far-field VSP -> SWP TransformFar-field VSP -> SWP Transform
SS 00
SS 0000
SS 0000++
• MotivationMotivation
• Interferometry TheoryInterferometry Theory
• Numerical Examples: 3 Syn. DataNumerical Examples: 3 Syn. Data
• ConclusionConclusion
OutlineOutline
FD ExperimentFD Experiment
Offset (m)Offset (m)00 10001000
DepthDepth (m)(m)
15001500
35003500 Depth (m)Depth (m)15001500 35003500
TimeTime (s)(s)
00
33
Reflection Reflection wavefieldwavefield
Reduced Form GSMReduced Form GSMRay tracing of line sourceRay tracing of line source (picked direct wave)(picked direct wave) Reduce form GSM resultReduce form GSM result
Offset (m)Offset (m)00 10001000
DepthDepth (m)(m)
15001500
35003500Offset (m)Offset (m)00 10001000
??
Reduced Form GSMReduced Form GSMRay tracing of line sourceRay tracing of line source (picked direct wave)(picked direct wave) Reduce form GSM resultReduce form GSM result
Offset (m)Offset (m)00 10001000
DepthDepth (m)(m)
15001500
35003500Offset (m)Offset (m)00 10001000
??
Lesson: Super-resolutionLesson: Super-resolution
Synthetic ExperimentSynthetic Experiment(He, 2006)(He, 2006)
94 geophones
10 shots10 shots
Overburden
0 km0 km 7 km7 kmOffset (m)Offset (m)
DepthDepth (m)(m)
55005500
00
A Shot GatherA Shot Gather
2 km2 km 6.5 km6.5 km
0 s0 s
5 s5 s
WEIM Result (one shot)WEIM Result (one shot)
Offset Offset (m)(m)
00 17001700
Dep
th (
m)
Dep
th (
m)
27002700
55005500
ArtifactsArtifacts
WEIM Result (ten shots)WEIM Result (ten shots)
Offset Offset (m)(m)
00 17001700
Dep
th (
m)
Dep
th (
m)
27002700
55005500
Tricks: Filter down and up going waves: m(x) = U(x)/D(x)Tricks: Filter down and up going waves: m(x) = U(x)/D(x)Lesson: Fltering+extra stacking reduces artifacts Lesson: Fltering+extra stacking reduces artifacts
• MotivationMotivation
• Interferometry TheoryInterferometry Theory
• Numerical Examples: GOM DataNumerical Examples: GOM Data
• ConclusionConclusion
OutlineOutline
VSP Salt Flank Imaging VSP Salt Flank Imaging (BP Hornby et al, 2006)(BP Hornby et al, 2006)
? 98 geophones
120 shots
Overburden
Poor image of flank by standard migrationPoor image of flank by standard migration
0 2000 ft 0 2000 ft
VSP DataVSP Data
3.2 s3.2 s
7.2 s7.2 s
0 2000 ft 0 2000 ft
Interferometric Migration Interferometric Migration ResultResult
VSP->SWP SummaryVSP->SWP Summary
3. Kills Source Statics and no need to know src location or excitation time3. Kills Source Statics and no need to know src location or excitation time
1. Redatum sources below overburden1. Redatum sources below overburden
2. Local VSP migration2. Local VSP migration
4. Super-resolution4. Super-resolution
5. Instead of redatuming receivers to surface, we5. Instead of redatuming receivers to surface, we
redatum sources to depth.redatum sources to depth.
X (m) 14001000
950
1950
Dep
th (
m)
Main Parameters in VSP:
• Source number: 100
• Shot interval: 10 m
• Receiver number: 91
• Receiver interval: 10 m
• Depth of the first receiver: 950 m
• Depth of the last receiver: 1850 m
• Temporal interval: 0.001 s