1. paul@sep.stanford.edu Multiple attenuation in the image space Paul Sava & Antoine Guitton Stanford University SEP

2. paul@sep.stanford.edu Goal Method feasible in 3-D Less expensive Dense data requirement Exploit the data/imaging mismatch Data: two-way propagation Migration: one-way extrapolation

3. paul@sep.stanford.edu Key technology Migration by wavefield extrapolation (WEM) Angle-domain common-image gathers High resolution Radon Transforms

4. paul@sep.stanford.edu The big picture WE prediction S/N separation Data RT & Mute Image Data NMO RT & Mute WE migration & ADCIG Image

5. paul@sep.stanford.edu Multiple attenuation by RTs –Moveout analysis NMO –Moveout analysis WE migration –S/N separation RT + Mute –S/N separation RT + Mute

6. paul@sep.stanford.edu 3-D depth imaging WE migration –Multi-arrival Angle-gathers –Single-valued Kirchhoff migration –Single-arrival Offset-gathers –Multi-valued Biondi et al. (2003) Stolk & Symes (2002)   z x y

7. paul@sep.stanford.edu Synthetic example: data vs. image CMP CIG

8. paul@sep.stanford.edu Which Radon transform? Generic Radon Transform Parabolic Biondi & Symes (2003) Tangent q g(  )  z

9. paul@sep.stanford.edu Synthetic example: RTs Tangent Parabolic

10. paul@sep.stanford.edu Synthetic example: S/N separation primaries & multiples primariesmultiplesART + muteART

11. paul@sep.stanford.edu BP synthetic example

12. paul@sep.stanford.edu primaries & multiples primariesmultiplesART BP synthetic example

13. paul@sep.stanford.edu primaries & multiples primariesmultiples BP synthetic example: stacks

14. paul@sep.stanford.edu GOM example

15. paul@sep.stanford.edu primaries & multiples primariesmultiplesART + muteART GOM example: CIG 1

16. paul@sep.stanford.edu GOM example

17. paul@sep.stanford.edu primaries & multiples primariesmultiplesART + muteART GOM example: CIG 2

18. paul@sep.stanford.edu GOM example

19. paul@sep.stanford.edu GOM example: zoom 1 primaries & multiples

20. paul@sep.stanford.edu GOM example: zoom 1 primaries

21. paul@sep.stanford.edu GOM example: zoom 1 primaries & multiples

22. paul@sep.stanford.edu GOM example: zoom 1 multiples

23. paul@sep.stanford.edu GOM example

24. paul@sep.stanford.edu GOM example: zoom 2 primaries & multiples

25. paul@sep.stanford.edu GOM example: zoom 2 primaries

26. paul@sep.stanford.edu GOM example: zoom 2 primaries & multiples

27. paul@sep.stanford.edu GOM example: zoom 2 multiples

28. paul@sep.stanford.edu RT comparison Image space RTData space RT

29. paul@sep.stanford.edu Discussion PROs –Cheap & robust –3-D –Simple primaries –Migration artifacts CONs –Velocity model? –Moveout function? –Interactive mute –Inner angles –RT artifacts

30. paul@sep.stanford.edu Summary WE prediction S/N separation Data RT & Mute Image Data NMO RT & Mute WE migration & ADCIG Image

31. paul@sep.stanford.edu Summary Multiple attenuation after migration WE migration Angle gathers Cost/accuracy Complex propagation Cheap separation RT limitations filtering approach