1. paul@sep.stanford.edu Prestack Stolt residual migration Paul Sava* Stanford University Biondo Biondi Stanford University

2. paul@sep.stanford.edu When is the velocity “correct”?

3. paul@sep.stanford.edu Motivation Why residual migration? image enhancement Why prestack? migration velocity analysis illumination Why Stolt residual migration? fast, robust

4. paul@sep.stanford.edu Agenda Prestack residual migration Examples Motivation Methodology

5. paul@sep.stanford.edu Prestack Stolt residual migration

6. paul@sep.stanford.edu Prestack & post-stack

7. paul@sep.stanford.edu Prestack Stolt residual migration Fourier-domain global action depth Velocity ratio (  Velocity ratio (no explicit velocity) Prestack

8. paul@sep.stanford.edu Agenda Prestack residual migration Examples Motivation Methodology

9. paul@sep.stanford.edu correct velocity incorrect velocity Example 1 residual migration

10. paul@sep.stanford.edu Example 2

11. paul@sep.stanford.edu Example 3 illumination or velocity?

12. paul@sep.stanford.edu original imageresidual moveoutresidual migration Example 3: comparison

13. paul@sep.stanford.edu before residual migration after residual migration Example 3

14. paul@sep.stanford.edu Summary Residual migration –Fourier-domain method –Prestack –No explicit knowledge of velocity Analogous to Stolt migration fast and robust global action