1. Multiple attenuation in the image space
Paul Sava & Antoine Guitton
Stanford University
SEP

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

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

4. The big picture Data NMO RT & Mute WE migration & ADCIG Image Data
S/N separation
WE prediction
S/N separation

5. Multiple attenuation by RTs
Moveout analysis
NMO
Moveout analysis
WE migration
S/N separation
RT + Mute
S/N separation
RT + Mute

6. 3-D depth imaging WE migration Angle-gathers Kirchhoff migration
Multi-arrival
Angle-gathers
Single-valued
Kirchhoff migration
Single-arrival
Offset-gathers
Multi-valued g
Biondi et al. (2003)
Stolk & Symes (2002) z x y

7. Synthetic example: data vs. image
CMP
CIG

8. Which Radon transform? Generic Radon Transform Parabolic q Tangent
g(g) g z
Parabolic
Tangent
Biondi & Symes (2003)

9. Synthetic example: RTs
Parabolic
Tangent

10. Synthetic example: S/N separation
primaries &
multiples
ART
ART + mute
multiples
primaries

11. BP synthetic example

12. BP synthetic example primaries & multiples ART multiples primaries

13. BP synthetic example: stacks
primaries &
multiples
multiples
primaries

14. GOM example

15. GOM example: CIG 1 primaries & multiples ART ART + mute multiples

16. GOM example

17. GOM example: CIG 2 primaries & multiples ART ART + mute multiples

18. GOM example

19. GOM example: zoom 1
primaries & multiples

20. GOM example: zoom 1
primaries

21. GOM example: zoom 1
primaries & multiples

22. GOM example: zoom 1
multiples

23. GOM example

24. GOM example: zoom 2
primaries & multiples

25. GOM example: zoom 2
primaries

26. GOM example: zoom 2
primaries & multiples

27. GOM example: zoom 2
multiples

28. RT comparison
Image space RT
Data space RT

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

30. Summary Data NMO RT & Mute WE migration & ADCIG Image Data RT & Mute
S/N separation
WE prediction
S/N separation

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