overview of sep research
DESCRIPTION
Overview of SEP research. Paul Sava. The problem. Modeling operator. Seismic image. Seismic data. Migration. Migration operator. Seismic image. Seismic data. Migration operator: wavefield propagation. Downward continuation Common-azimuth migration Narrow-azimuth migration - PowerPoint PPT PresentationTRANSCRIPT
Overview of SEP research
Paul Sava
The problem
dmLModeling operator
Seismic image
Seismic data
Migration
dm *LMigration operator
Seismic image
Seismic data
Migration operator: wavefield propagation
• Downward continuation– Common-azimuth migration– Narrow-azimuth migration
• Reverse time migration
dm *L • Propagation• Imaging• Amplitudes• Velocity
Downward continuation
Narrow-azimuth
Common-azimuth
Biondi, 2003
Reverse-time migrationBiondi & Shan, 2002
Downward-continuation
Reverse-time migration
Migration operator: angle-gathers
• Data-space• Prucha et al
• Image-space• Sava&Fomel, Tisserant&Biondi (S-G)• Rickett&Sava (shot profile)• Rosales&Rickett (converted waves)• Biondi&Shan (reverse-time)
dm *L • Propagation• Imaging• Amplitudes• Velocity
Prucha et. Al (1999), Sava&Fomel (2002)
Angle-domain common image gathers
Data-space ADCIG
Image space ADCIG
3-D angle gathersTisserant & Biondi (2003)
Migration operator: amplitudes
• Amplitude preserving wavefield extrapolation• Sava & Biondi
• Amplitude corrections of extrapolation operators• Vlad et. al
• Hi resolution imaging condition• Valenciano & Biondi
dm *L • Propagation• Imaging• Amplitudes• Velocity
Amplitude-preserving migrationSava & Biondi (2002)
Amplitude preserving
Kinematic migration
Migration operator: velocity
• Traveltime-based• Clapp
• Wavefield-based• Sava & Biondi
dm *L • Propagation• Imaging• Amplitudes• Velocity
Angle-domain traveltime tomographyClapp (2001)
Tomography: geological constraintsClapp (2001)
1 -.4
-.6
Wave-equation MVA
Slowness perturbation
Image perturbation
Sava & Biondi (2003)
z
z
xx
Wave-equation MVASava & Biondi (2003)
Multiple attenuation
• Multiple attenuation– Data space– Image space
• Multiple imaging• Joint imaging
dm *L
2.6
5.
Tim
e (
s)Input data
HyperbolicRadon
Adaptivefiltering
Patternrecognition
Multiple attenuation: data spaceGuitton (2003)
PRT image space
HRT data
space
Multiple attenuation: image spaceSava & Guitton (2003)
Multiple imaging
• Multiple attenuation– Data space– Image space
• Multiple imaging• Joint imaging
dm *L
Multiple imaging: shot-profile migrationGuitton (2002)
Up-goingwavefield
Down-goingwavefield
PrimariesImpulse
Up-goingwavefield
Down-goingwavefield
MultiplesPrimaries
Primaries imaging Multiples imaging
Multiple imaging: S-G migration Shan (2003)
sx sxDx DxUx Uxh x h
1t
2t
2t1R 1R
2R 2R
Joint imaging
• Multiple attenuation– Data space– Image space
• Multiple imaging• Joint imaging
dm *L
Joint imagingBrown (2003)
S G
Migration
dm *LMigration operator
Seismic image
Seismic data
Inversion operator
Least-squares imaging
dm *1* LLL
Seismic image
Seismic data
dm *WL
Least-squares imaging
• Normalized migration• Matching filters• Least-squares inverse• Multiple realizations
• Illumination compensation• Rickett (2001)• Prucha (2003)
Normalized migrationRickett (2003)
dm *BL
Least-squares imagingGuitton (2003)
• Normalized migration• Matching filters• Least-squares inverse• Multiple realizations
(L*L)-1
data
L*
1m L*L
2m
B"" truem
Find B such that
12 mBm
Imaging with mathching filtersGuitton (2003)
Least-squares inverse
dm *1* LLL
• Normalized migration• Matching filters• Least-squares inverse• Multiple realizations
dm *1*2* ε LAALL
Regularization
z-x
preconditioning
z
x
z-ph
preconditioning
z
ph
Prucha (2003)
Regularized inversionPrucha (2003)
Least-squares inverse
Migration
Multiple realizations
dm *1* LLL
• Normalized migration• Matching filters• Least-squares inverse• Multiple realizations
dm *1*2* ε LAALL
0mA0 dmL
Multiple realizations: interpolationClapp (2002)
0mA0 dmL
nmA0 dmL
Multiple realizations: velocityClapp (2002)
http://sepwww.stanford.edu
• Reports (all online)
• Seplib
• Computers: 4 clusters
• 3D real data