Revealing geological discontinuities by local plane wave suppression

Matthias Schwab, Curt Holden, and Jon Claerbout

matt@sep.stanford.edu, curt@sep.stanford.edu, jon@sep.stanford.edu

ABSTRACT

Interpreters of migrated seismic image volumes need to delineate reflector discontinuities, such as faults or buried channels. To enhance these discontinuities we applied local, data-adaptive Prediction Error (PE) Filters to the migrated image. We restricted the PE Filters to local combinations of 2-D filters, which remove local planar events and reveal rapidly varying local features. Unfortunately, while the scheme successfully enhanced geological discontinuities in one field data case, it failed in two others. In these two cases, the PE Filters erroneously predicted (and consequently removed) the geological discontinuities of interest. We were unable to tune the PE Filters to forgo a specific target bandwidth. Such a tuning may be possible if we use a sequence of two PE filtering steps of which the first filter prewhitens the image. In another case, the PE filter enhanced the image's acquisition footprint and thereby obliterated any geological details. Moreover, we do not yet know how to combine optimally the various PE Filter residuals to produce a meaningful subsurface map.