prestack migration deconvolution jianxing hu and gerard t. schuster university of utah

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  • Slide 1
  • Prestack Migration Deconvolution Jianxing Hu and Gerard T. Schuster University of Utah
  • Slide 2
  • Outline MotivationMotivation MethodologyMethodology Numerical TestsNumerical Tests ConclusionsConclusions
  • Slide 3
  • Comparison of Poststack MD Depth Slices 6 8 Y (km) Y (km) X (km) X (km)4 8 6 10 10 Kirchhoff Image Kirchhoff Image MD Image MD Image 6 8 Y (km) Y (km) X (km) X (km)4 8 6 10 10
  • Slide 4
  • Comparison of Prestack Migration and MD Images X (km) X (km) 4 6 8 10 10 1 4 Depth (km) Depth (km) X (km) X (km) 4 6 8 10 10 1 4 Depth (km) Depth (km) Prestack Kirchhoff Migration Image of Prestack Kirchhoff Migration Image of a North Sea Data Set a North Sea Data Set MD Image
  • Slide 5
  • Outline MotivationMotivation MethodologyMethodology Numerical TestsNumerical Tests ConclusionsConclusions
  • Slide 6
  • Modeling and Migration Seismic data Reflectivity Greens Function Model Space Migrated Image Data Space Seismic Data Forward Modeling: Migration: Wavelet
  • Slide 7
  • Model Space Where: Denote as the migration Greens Function Relation of Migrated Image and Reflectivity Distribution Relation of Migrated Image and Reflectivity Distribution Data Space
  • Slide 8
  • Reflectivity Modulated by Migration Greens Function Model Space
  • Slide 9
  • Migration Deconvolution Model Space Model Space --- reference position of migration Greens function
  • Slide 10
  • Lateral Velocity Variation Multi-Reference migration Greens function Subdivide the migration image area and use multi- reference migration Greens function to account for lateral velocity variation and far-field artifacts
  • Slide 11
  • Methodology Calculate migration Greens function Recording geometry & migrated image dimension Velocity Model + Traveltime Table Migration Greens function
  • Slide 12
  • Methodology Apply migration deconvolution filter to the stacked prestack migration image 5 Offset(km) 6 5 1 2 3 Depth (km) RTM Migration Image Deconvolved Image Deconvolved Image Pseudo-Convolution Offset(km) 6 5 1 2 3 Depth (km) RTM
  • Slide 13
  • Difference between Poststack MD and Prestack MD Zero-offset trace location & migrated image dimension Velocity Model Traveltime Table migration Poststack migration Greens function Greens function + migration Prestack migration Greens function Greens function Recording Geometry & migrated image dimension +
  • Slide 14
  • Outline MotivationMotivation MethodologyMethodology Numerical TestsNumerical Tests ConclusionsConclusions
  • Slide 15
  • Numerical Tests 3-D point scatterer model3-D point scatterer model 3-D meandering stream model3-D meandering stream model 2-D SEG/EAGE overthrust model2-D SEG/EAGE overthrust model 2-D Husky data set (Canadian Foothills)2-D Husky data set (Canadian Foothills) 3-D SEG/EAGE salt model3-D SEG/EAGE salt model 3-D West Texas data set3-D West Texas data set
  • Slide 16
  • 5 X 5 Sources; 21 X 21 Receivers (0, 0) (1km, 0) (1km, 1km) (0, 1km) Point scatterer Recording Geometry Wavelet frequency 50 Hz
  • Slide 17
  • Prestack KM vs. Prestack MD Y X Y X Y X Y X
  • Slide 18
  • Prestack KM vs. Poststack MD Y X Y X Y X Y X
  • Slide 19
  • Numerical Tests 3-D point scatterer model3-D point scatterer model 3-D meandering stream model3-D meandering stream model 2-D SEG/EAGE overthrust model2-D SEG/EAGE overthrust model 2-D Husky data set (Canadian Foothills)2-D Husky data set (Canadian Foothills) 3-D SEG/EAGE salt model3-D SEG/EAGE salt model 3-D West Texas data set3-D West Texas data set
  • Slide 20
  • (0, 0) (1 km, 0) (1 km,1 km) (0, 1 km) A river channel Recording Geometry 5 X 5 Sources; 21 X 21 Receivers Wavelet frequency 50 Hz
  • Slide 21
  • Meandering River Model 01000 X (m) 0 1000 Y (m)
  • Slide 22
  • Kirchhoff Migration Image 01000 X (m) 0 1000 Y (m)
  • Slide 23
  • MD Image 01000 X (m) 0 1000 Y (m)
  • Slide 24
  • Numerical Tests 3-D point scatterer model3-D point scatterer model 3-D meandering stream model3-D meandering stream model 2-D SEG/EAGE overthrust model2-D SEG/EAGE overthrust model 2-D Husky data set (Canadian Foothills)2-D Husky data set (Canadian Foothills) 3-D SEG/EAGE salt model3-D SEG/EAGE salt model 3-D West Texas data set3-D West Texas data set
  • Slide 25
  • Prestack Migration Image Prestack Migration Image Deconvolved Migration Image Deconvolved Migration Image 0 km 20 km 20 km 0 km 4 km 20 km 0 km 0 km 0 km 4 km X(km) Depth (km)
  • Slide 26
  • Zoom View of KM and MD Prestack KM Prestack MD 2 4 3 Depth (km) 37 X (km) 2 4 3 Depth (km) 37 X (km)
  • Slide 27
  • Numerical Tests 3-D point scatterer model3-D point scatterer model 3-D meandering stream model3-D meandering stream model 2-D SEG/EAGE overthrust model2-D SEG/EAGE overthrust model 2-D Husky data set (Canadian Foothills)2-D Husky data set (Canadian Foothills) 3-D SEG/EAGE salt model3-D SEG/EAGE salt model 3-D West Texas data set3-D West Texas data set
  • Slide 28
  • Husky Prestack Migration Image 4 6X(km)0 0 10 5 2 Depth (km)
  • Slide 29
  • Velocity Model for Husky Data 6X(km)0 0 10 5 2 Depth (km) 7000 3200 Velocity (m/s)
  • Slide 30
  • MD with 20 reference positions 6X(km)0 0 10 5 2 Depth (km) A
  • Slide 31
  • KM X(km) 95 1 3 Depth (km) MD X(km)95 1 3 Depth (km)
  • Slide 32
  • MD with 20 reference positions 6X(km)0 0 10 5 2 Depth (km) B
  • Slide 33
  • KM X(km) 1411 1 3 Depth (km) MD X(km)1411 1 3 Depth (km)
  • Slide 34
  • MD with 20 reference positions 6X(km)0 0 10 5 2 Depth (km) C
  • Slide 35
  • KM X(km)1410 2 5 Depth (km) MD X(km)1410 2 5 Depth (km)
  • Slide 36
  • Numerical Tests 3-D point scatterer model3-D point scatterer model 3-D meandering stream model3-D meandering stream model 2-D SEG/EAGE overthrust model2-D SEG/EAGE overthrust model 2-D Husky data set2-D Husky data set 3-D SEG/EAGE salt model3-D SEG/EAGE salt model 3-D West Texas data set3-D West Texas data set
  • Slide 37
  • KM Inline (97,Y) Section MD Inline (97,Y) Section 58 Y (km) 58 0 4 2 04 2 Depth (km)
  • Slide 38
  • KM Crossline (X,97) Section MD Crossline (X,97) Section 04 2 Depth (km) 118 X (km) 118 X (km) 04 2
  • Slide 39
  • Numerical Tests 3-D point scatterer model3-D point scatterer model 3-D meandering stream model3-D meandering stream model 2-D SEG/EAGE overthrust model2-D SEG/EAGE overthrust model 2-D Husky data set2-D Husky data set 3-D SEG/EAGE salt model3-D SEG/EAGE salt model 3-D West Texas data set3-D West Texas data set
  • Slide 40
  • KMMD03 X(kft)46 8 Depth (kft) 4 6 8 03 X(kft)
  • Slide 41
  • 46 8 Depth (kft) KMMD4 6 8 X(kft)2 4 2 4
  • Slide 42
  • Outline MotivationMotivation MethodologyMethodology Numerical TestsNumerical Tests ConclusionsConclusions
  • Slide 43
  • Conclusions Works well on 2-D land and 3-D synthetic marine prestack data More work is needed to remedy the problems in MD for 3-D land prestack data Standard post-migration processing procedure ?
  • Slide 44
  • Acknowledgement Thank 1999 UTAM sponsors for their financial supportThank 1999 UTAM sponsors for their financial support