Paper Summary

Subsalt velocity updating (Wang et al., 2004, 2006) can be categorized into two approaches: 1) Datadriven subsalt tomography based on residual moveouts; and 2) interpretation-driven subsalt WEM scans (Wang et al., 2006). When subsalt reflections are well defined and their reflection angle range is broad, subsalt tomography works just as well as suprasalt tomography. On the other hand, if subsalt reflections are not well defined or the range of reflection angle is limited, as is often the case, we may have to rely on a more brute force approach such as subsalt WEM scan.