wavepath migration versus kirchhoff migration: 3-d prestack examples
DESCRIPTION
H. Sun and G. T. Schuster. University of Utah. Wavepath Migration versus Kirchhoff Migration: 3-D Prestack Examples. Outline. Problems in Kirchhoff Migration Wavepath Migration Implementation of WM Numerical Results Conclusions. Specular Ray. Forward Modeling. - PowerPoint PPT PresentationTRANSCRIPT
Wavepath Migration versus Wavepath Migration versus Kirchhoff Migration: 3-D Kirchhoff Migration: 3-D
Prestack ExamplesPrestack Examples
H. Sun and G. T. SchusterH. Sun and G. T. SchusterUniversity of UtahUniversity of Utah
OutlineOutline Problems in Kirchhoff MigrationProblems in Kirchhoff Migration• Wavepath Migration Wavepath Migration • Implementation of WMImplementation of WM• Numerical ResultsNumerical Results• ConclusionsConclusions
Forward ModelingForward Modeling
( Xg, 0 )( Xg, 0 ) ( Xs, 0 )( Xs, 0 )
Specular RaySpecular Ray
3D Kirchhoff Migration3D Kirchhoff Migration
( Xg, 0 )( Xg, 0 ) ( Xs, 0 )( Xs, 0 )
3D Fat Ellipsoid3D Fat Ellipsoid
3-D KM of a Single Trace3-D KM of a Single Trace
RR SSAA
AA
BB
BB
CC
CC
Problems in Kirchhoff MigrationProblems in Kirchhoff Migration
Traveltime InformationTraveltime Information
Where Was Wave Reflected ?Where Was Wave Reflected ?
The Whole Fat Ellipsoid !The Whole Fat Ellipsoid !
Problem 1Problem 1
Strong Far-FieldStrong Far-FieldMigration ArtifactMigration Artifact
Problem 2Problem 2
Slow for 3-D IterativeSlow for 3-D IterativeVelocity AnalysisVelocity Analysis
OutlineOutline• Problems in Kirchhoff MigrationProblems in Kirchhoff Migration Wavepath Migration Wavepath Migration • Implementation of WMImplementation of WM• Numerical ResultsNumerical Results• ConclusionsConclusions
3D Wavepath Migration3D Wavepath Migration
( Xg, 0 )( Xg, 0 )
Fat RayFat Ray
Fat Fat EllipsoidEllipsoid
KM : Fat Ellipsoid, O(N )KM : Fat Ellipsoid, O(N )WM: Hatching Area, O(N )WM: Hatching Area, O(N )
3 3
1.5 1.5
3-D WM of a Single Trace3-D WM of a Single Trace
RR SSAA
BBCC
AABB
CC
Traveltime + Ray DirectionTraveltime + Ray Direction
TrueReflection point
SmallMigration Aperture
FewerFewerArtifactsArtifacts
LessLessExpensiveExpensive
Wavepath MigrationWavepath Migration
• To Achieve Higher CPU EfficiencyTo Achieve Higher CPU Efficiency Compared to 3-D KMCompared to 3-D KM • To Generate Comparable or BetterTo Generate Comparable or Better Image Quality than 3-D KMImage Quality than 3-D KM
Key Goals of 3-D WMKey Goals of 3-D WM
Related ReferencesRelated References• Time-Map MigrationTime-Map Migration SherrifSherrif & & GeldhartGeldhart (1985) (1985)• Wave Equation TomographyWave Equation Tomography Woodward Woodward && Rocca Rocca (1988) (1988)• Gaussian Beam MigrationGaussian Beam Migration Ross HillRoss Hill (1990) (1990)• Kirchhoff Beam MigrationKirchhoff Beam Migration Yonghe SunYonghe Sun et al., (1999) et al., (1999)
OutlineOutline• Problems in Kirchhoff MigrationProblems in Kirchhoff Migration• Wavepath Migration Wavepath Migration Implementation of WMImplementation of WM• Numerical ResultsNumerical Results• ConclusionsConclusions
Key Steps in WMKey Steps in WM
RaypathRaypath
RR SS
RaypathRaypath Fresnel Zone MigrationFresnel Zone MigrationQuasi-ellipsoidQuasi-ellipsoid
Quasi-ellipsoidQuasi-ellipsoid
OutlineOutline• Problems in Kirchhoff MigrationProblems in Kirchhoff Migration• Wavepath Migration Wavepath Migration • Implementation of WMImplementation of WM Numerical ResultsNumerical Results 3-D Prestack Point Scatterer Data3-D Prestack Point Scatterer Data 3-D Prestack SEG/EAGE Salt Data3-D Prestack SEG/EAGE Salt Data 3-D Prestack West Texas Field Data3-D Prestack West Texas Field Data• ConclusionsConclusions
3-D Prestack KM Point Scatterer Response3-D Prestack KM Point Scatterer Response R
efle
ctiv
ity
Ref
lect
ivit
y
Y Offset (km)Y Offset (km) X Offset (km)X Offset (km)
11
-0.5-0.5
00
11
Ref
lect
ivit
yR
efle
ctiv
ity
Y Offset (km)Y Offset (km) X Offset (km)X Offset (km)
11
-0.01-0.01
00
0.020.02
Ref
lect
ivit
yR
efle
ctiv
ity
Y Offset (km)Y Offset (km) X Offset (km)X Offset (km)
11
-0.05-0.05
00
0.10.1
Ref
lect
ivit
yR
efle
ctiv
ity
Y Offset (km)Y Offset (km) X Offset (km)X Offset (km)
11
-0.2-0.2
00
0.40.4
11
1111
11
Z0Z0
Z0-1Z0-1Z0-9Z0-9
Z0+8Z0+8
Ref
lect
ivit
yR
efle
ctiv
ity
Y Offset (km)Y Offset (km) X Offset (km)X Offset (km)
11
-0.5-0.5
00
11
Ref
lect
ivit
yR
efle
ctiv
ity
Y Offset (km)Y Offset (km) X Offset (km)X Offset (km)
11
-0.01-0.01
00
0.020.02
Ref
lect
ivit
yR
efle
ctiv
ity
Y Offset (km)Y Offset (km) X Offset (km)X Offset (km)
11
-0.05-0.05
00
0.10.1
Ref
lect
ivit
yR
efle
ctiv
ity
Y Offset (km)Y Offset (km) X Offset (km)X Offset (km)
11
-0.2-0.2
00
0.40.4
11
1111
11
3-D Prestack WM Point Scatterer Response3-D Prestack WM Point Scatterer Response
Z0Z0
Z0-1Z0-1Z0-9Z0-9
Z0+8Z0+8
OutlineOutline• Problems in Kirchhoff MigrationProblems in Kirchhoff Migration• Wavepath Migration Wavepath Migration • Implementation of WMImplementation of WM Numerical ResultsNumerical Results 3-D Prestack Point Scatterer Data3-D Prestack Point Scatterer Data 3-D Prestack SEG/EAGE Salt Data3-D Prestack SEG/EAGE Salt Data 3-D Prestack West Texas Field Data3-D Prestack West Texas Field Data• ConclusionsConclusions
A Common Shot GatherA Common Shot GatherTrace NumberTrace Number11 390390
Tim
e (s
ec)
Tim
e (s
ec)
00
5.05.0
Inline Velocity ModelInline Velocity Model
Offset (km)Offset (km)00 9.29.2
Dep
th (
km)
Dep
th (
km)
00
3.83.8
SALTSALT
Inline KMInline KM ((CPU=1CPU=1)) Inline WMInline WM ((CPU=1/33CPU=1/33))
Offset (km)Offset (km)00 9.29.2
00
3.83.8
De
pth
(k
m)
De
pth
(k
m)
Offset (km)Offset (km)00 9.29.2
Inline KMInline KM ((CPU=1CPU=1)) Inline WMInline WM ((CPU=1/170CPU=1/170))
Offset (km)Offset (km)00 9.29.2
00
3.83.8
De
pth
(k
m)
De
pth
(k
m)
Offset (km)Offset (km)00 9.29.2
(subsample)(subsample)
Zoom Views of Inline Sections Zoom Views of Inline Sections
Offset: 3~6.5 km, Depth: 0.3~1.8 kmOffset: 3~6.5 km, Depth: 0.3~1.8 km
WMWM
ModelModel
KM KM
SubSubWMWM
Offset: 1.8~4 km, Depth: 0.6~2.1 kmOffset: 1.8~4 km, Depth: 0.6~2.1 km
WMWM
ModelModel
KM KM
SubSubWMWM
Zoom Views of Crossline Sections Zoom Views of Crossline Sections
Inline: 1.8~7.2 km, Crossline: 0~4 kmInline: 1.8~7.2 km, Crossline: 0~4 km
WMWM
ModelModel
KM KM
SubSubWMWM
Horizontal Slices (Depth=1.4 km) Horizontal Slices (Depth=1.4 km)
OutlineOutline• Problems in Kirchhoff MigrationProblems in Kirchhoff Migration• Wavepath Migration Wavepath Migration • Implementation of WMImplementation of WM Numerical ResultsNumerical Results 3-D Prestack Point Scatterer Data3-D Prestack Point Scatterer Data 3-D Prestack SEG/EAGE Salt Data3-D Prestack SEG/EAGE Salt Data 3-D Prestack West Texas Field Data3-D Prestack West Texas Field Data• ConclusionsConclusions
A Common Shot GatherA Common Shot GatherTrace NumberTrace Number5454 193193
Tim
e (s
ec)
Tim
e (s
ec)
00
3.43.4
Inline KM Inline KM ((CPU=1CPU=1)) Inline WMInline WM ((CPU=1/14CPU=1/14))
Offset (km)Offset (km)0.40.4 4.54.5
0.80.8
3.83.8
De
pth
(k
m)
De
pth
(k
m)
Offset (km)Offset (km)0.40.4 4.54.5
Inline KMInline KM ((CPU=1CPU=1)) Inline WMInline WM ((CPU=1/50CPU=1/50))
Offset (km)Offset (km)0.40.4 4.54.5
0.80.8
3.83.8
De
pth
(k
m)
De
pth
(k
m)
Offset (km)Offset (km)0.40.4 4.54.5
(subsample)(subsample)
Crossline KM Crossline KM ((CPU=1CPU=1)) Crossline WMCrossline WM ((CPU=1/14CPU=1/14))
Offset (km)Offset (km)0.30.3 3.53.5
0.80.8
3.33.3
De
pth
(k
m)
De
pth
(k
m)
Offset (km)Offset (km)0.30.3 3.53.5
Crossline KMCrossline KM ((CPU=1CPU=1)) Crossline WMCrossline WM ((CPU=1/50CPU=1/50))(subsample)(subsample)
Offset (km)Offset (km)0.30.3 3.53.5
0.80.8
3.33.3
De
pth
(k
m)
De
pth
(k
m)
Offset (km)Offset (km)0.30.3 3.53.5
Inline: 0~4.6 km, Crossline: 0~3.8Inline: 0~4.6 km, Crossline: 0~3.8
KM (KM (CPU=1CPU=1))
Horizontal Slices (Depth=2.5 km) Horizontal Slices (Depth=2.5 km)
WM (WM (CPU=1/14CPU=1/14)) WM (Sub, WM (Sub, CPU=1/50CPU=1/50))
OutlineOutline• Problems in Kirchhoff MigrationProblems in Kirchhoff Migration• Wavepath Migration Wavepath Migration • Implementation of WMImplementation of WM• Numerical ResultsNumerical Results ConclusionsConclusions
ConclusionsConclusions
SEG/EAGE Salt DataSEG/EAGE Salt Data• Fewer Migration ArtifactsFewer Migration Artifacts• Better for Complex Salt BoundaryBetter for Complex Salt Boundary• Higher Computational EfficiencyHigher Computational Efficiency
CPUCPU KM: KM: 11 WM: WM: 1/331/33 Subsampled WM: Subsampled WM: 1/1701/170
ConclusionsConclusions
West Texas Field DataWest Texas Field Data• Fewer Migration ArtifactsFewer Migration Artifacts• Similar Image QualitySimilar Image Quality• Higher Computational EfficiencyHigher Computational Efficiency
CPUCPU KM: KM: 11 WM: WM: 1/141/14 Subsampled WM: Subsampled WM: 1/501/50
AcknowledgementsAcknowledgements
We thank UTAM sponsorsWe thank UTAM sponsorsfor their financial supportfor their financial support