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![Page 1: Mitigation of RTM Artifacts with Migration Kernel Decomposition Ge Zhan* and Gerard T. Schuster King Abdullah University of Science and Technology June.](https://reader035.fdocuments.us/reader035/viewer/2022062423/56649edb5503460f94bea7ac/html5/thumbnails/1.jpg)
Mitigation of RTM Artifacts
with Migration Kernel DecompositionGe Zhan* and Gerard T. Schuster
King Abdullah University of Science and Technology
June 7, 2012
![Page 2: Mitigation of RTM Artifacts with Migration Kernel Decomposition Ge Zhan* and Gerard T. Schuster King Abdullah University of Science and Technology June.](https://reader035.fdocuments.us/reader035/viewer/2022062423/56649edb5503460f94bea7ac/html5/thumbnails/2.jpg)
Outline
• Introduction
• Method
• Examples Two-layer model BP salt model
• Conclusions0 25
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![Page 3: Mitigation of RTM Artifacts with Migration Kernel Decomposition Ge Zhan* and Gerard T. Schuster King Abdullah University of Science and Technology June.](https://reader035.fdocuments.us/reader035/viewer/2022062423/56649edb5503460f94bea7ac/html5/thumbnails/3.jpg)
Outline
• Introduction
• Method
• Examples Two-layer model BP salt model
• Conclusions
![Page 4: Mitigation of RTM Artifacts with Migration Kernel Decomposition Ge Zhan* and Gerard T. Schuster King Abdullah University of Science and Technology June.](https://reader035.fdocuments.us/reader035/viewer/2022062423/56649edb5503460f94bea7ac/html5/thumbnails/4.jpg)
Introduction --- Reverse-time migration (RTM)
Benefits:Images any dipping structure;Accounts for multiple arrivals; and etc.
Problems:intensive computational costssevere migration artifacts
![Page 5: Mitigation of RTM Artifacts with Migration Kernel Decomposition Ge Zhan* and Gerard T. Schuster King Abdullah University of Science and Technology June.](https://reader035.fdocuments.us/reader035/viewer/2022062423/56649edb5503460f94bea7ac/html5/thumbnails/5.jpg)
Introduction--- RTM artifacts
RTM artifacts usually present as strong-amplitude, low-frequency noisesin the migration image.
artifacts contaminate image
Various remedies have been proposed to suppress RTM artifacts: Smooth the velocity model before migration (Loewenthal et al., 1987); Low-cut filtering on migrated images (Mulder and Plessix, 2003);
Directional damping to non-reflection wave equation (Fletcher et al., 2005); Least-squares migration (Nemeth et al., 1999; Guitton et al., 2006); Migration deconvolution (Hu et al., 2001; Yu et al., 2006);
Poynting-vector imaging condition (Yoon and Marfurt, 2006); Wavefield decomposition using Hilbert transform (Liu et al., 2007; 2011).
![Page 6: Mitigation of RTM Artifacts with Migration Kernel Decomposition Ge Zhan* and Gerard T. Schuster King Abdullah University of Science and Technology June.](https://reader035.fdocuments.us/reader035/viewer/2022062423/56649edb5503460f94bea7ac/html5/thumbnails/6.jpg)
Outline
• Introduction
• Method
• Examples Two-layer model BP salt model
• Conclusions
![Page 7: Mitigation of RTM Artifacts with Migration Kernel Decomposition Ge Zhan* and Gerard T. Schuster King Abdullah University of Science and Technology June.](https://reader035.fdocuments.us/reader035/viewer/2022062423/56649edb5503460f94bea7ac/html5/thumbnails/7.jpg)
Method--- Seismic Survey
![Page 8: Mitigation of RTM Artifacts with Migration Kernel Decomposition Ge Zhan* and Gerard T. Schuster King Abdullah University of Science and Technology June.](https://reader035.fdocuments.us/reader035/viewer/2022062423/56649edb5503460f94bea7ac/html5/thumbnails/8.jpg)
Method--- Seismic Modeling
Recorded seismic data
![Page 9: Mitigation of RTM Artifacts with Migration Kernel Decomposition Ge Zhan* and Gerard T. Schuster King Abdullah University of Science and Technology June.](https://reader035.fdocuments.us/reader035/viewer/2022062423/56649edb5503460f94bea7ac/html5/thumbnails/9.jpg)
Method --- Reverse Time Migration (RTM)
Migration of seismic data
![Page 10: Mitigation of RTM Artifacts with Migration Kernel Decomposition Ge Zhan* and Gerard T. Schuster King Abdullah University of Science and Technology June.](https://reader035.fdocuments.us/reader035/viewer/2022062423/56649edb5503460f94bea7ac/html5/thumbnails/10.jpg)
Method --- Reverse Time Migration (RTM)
Migration of seismic data
![Page 11: Mitigation of RTM Artifacts with Migration Kernel Decomposition Ge Zhan* and Gerard T. Schuster King Abdullah University of Science and Technology June.](https://reader035.fdocuments.us/reader035/viewer/2022062423/56649edb5503460f94bea7ac/html5/thumbnails/11.jpg)
Method --- Reverse Time Migration (RTM)
Migration of seismic data
![Page 12: Mitigation of RTM Artifacts with Migration Kernel Decomposition Ge Zhan* and Gerard T. Schuster King Abdullah University of Science and Technology June.](https://reader035.fdocuments.us/reader035/viewer/2022062423/56649edb5503460f94bea7ac/html5/thumbnails/12.jpg)
Method --- Reverse Time Migration (RTM)
Migration of seismic data
![Page 13: Mitigation of RTM Artifacts with Migration Kernel Decomposition Ge Zhan* and Gerard T. Schuster King Abdullah University of Science and Technology June.](https://reader035.fdocuments.us/reader035/viewer/2022062423/56649edb5503460f94bea7ac/html5/thumbnails/13.jpg)
Method --- Reverse Time Migration (RTM)
Migration of seismic data
![Page 14: Mitigation of RTM Artifacts with Migration Kernel Decomposition Ge Zhan* and Gerard T. Schuster King Abdullah University of Science and Technology June.](https://reader035.fdocuments.us/reader035/viewer/2022062423/56649edb5503460f94bea7ac/html5/thumbnails/14.jpg)
Method --- Reverse Time Migration (RTM)
Migration of seismic data
![Page 15: Mitigation of RTM Artifacts with Migration Kernel Decomposition Ge Zhan* and Gerard T. Schuster King Abdullah University of Science and Technology June.](https://reader035.fdocuments.us/reader035/viewer/2022062423/56649edb5503460f94bea7ac/html5/thumbnails/15.jpg)
Method --- Generalized Diffraction Migration (GDM)
Migration of seismic data
![Page 16: Mitigation of RTM Artifacts with Migration Kernel Decomposition Ge Zhan* and Gerard T. Schuster King Abdullah University of Science and Technology June.](https://reader035.fdocuments.us/reader035/viewer/2022062423/56649edb5503460f94bea7ac/html5/thumbnails/16.jpg)
Method--- GDM Workflow
1. Compute & save Green’s functions for a given migration velocity;
2. Filter the Green’s functions into downgoing and upgoing components in F-K domain;
3. Convolve the appropriate components of filtered Green’s function to form the migration kernel; 4. Dot product of the migration kernel with the recorded seismic data to get the migration image. T
x
shotgather
T
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Migration Kernel
![Page 17: Mitigation of RTM Artifacts with Migration Kernel Decomposition Ge Zhan* and Gerard T. Schuster King Abdullah University of Science and Technology June.](https://reader035.fdocuments.us/reader035/viewer/2022062423/56649edb5503460f94bea7ac/html5/thumbnails/17.jpg)
Outline
• Introduction
• Method
• Examples Two-layer model BP salt model
• Conclusions
![Page 18: Mitigation of RTM Artifacts with Migration Kernel Decomposition Ge Zhan* and Gerard T. Schuster King Abdullah University of Science and Technology June.](https://reader035.fdocuments.us/reader035/viewer/2022062423/56649edb5503460f94bea7ac/html5/thumbnails/18.jpg)
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GDM
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RTM
Examples--- two-layer model
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Outline
• Introduction
• Method
• Examples Two-layer model BP salt model
• Conclusions
![Page 20: Mitigation of RTM Artifacts with Migration Kernel Decomposition Ge Zhan* and Gerard T. Schuster King Abdullah University of Science and Technology June.](https://reader035.fdocuments.us/reader035/viewer/2022062423/56649edb5503460f94bea7ac/html5/thumbnails/20.jpg)
Examples--- BP salt model
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1-shot RTM image
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Stacked RTM image
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High-pass-filtered RTM image
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Examples--- BP salt model
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Standard RTM w/ filtering
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Horizontal GDM image
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Vertical GDM image
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Stacked GDM image
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Outline
• Introduction
• Method
• Examples Two-layer model BP salt model
• Conclusions
![Page 23: Mitigation of RTM Artifacts with Migration Kernel Decomposition Ge Zhan* and Gerard T. Schuster King Abdullah University of Science and Technology June.](https://reader035.fdocuments.us/reader035/viewer/2022062423/56649edb5503460f94bea7ac/html5/thumbnails/23.jpg)
1). The kernel of RTM imaging operator is decomposed into products of downgoing and upgoing Green’s functions.2). This decomposition leads to an imaging algorithm with fewer artifacts and a higher-quality RTM image.3). Advantage: deterministic filtering of RTM kernel can be directly applied to reduce migration artifacts, mitigate multiples and eliminate aliasing artifacts.4). Drawback: significantly more storage capacity and I/O time than standard RTM.
Conclusions
5). There are still some residual artifacts, which can be further eliminated by least-squares migration.
![Page 24: Mitigation of RTM Artifacts with Migration Kernel Decomposition Ge Zhan* and Gerard T. Schuster King Abdullah University of Science and Technology June.](https://reader035.fdocuments.us/reader035/viewer/2022062423/56649edb5503460f94bea7ac/html5/thumbnails/24.jpg)
We thank the sponsors of the Center for Subsurface Imaging and Fluid Modeling (CSIM) at KAUST for their support.
Acknowledgments
We also thank BP for making the BP 2007 salt model available.
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Question or Suggestion?
Thank you for your attention!