oa CRS Offset-azimuth Regularisation of Wide-azimuth Seismic Data for Optimized Imaging and Amplitude Studies

Wide azimuth (WAZ) marine seismic data commonly provide an enhanced but varying coverage in azimuth-offset domain, which decreases towards crossline azimuths and near-offsets. The variable offset-azimuth illumination of WAZ data is commonly exploited in prestack depth migration in order to resolve complex subsurface structures, but often leads to amplitude footprints due to the variation, that disturb AVO and AVAZ analyses. An interpolation in azimuth-offset domain based on the CRS technique may largely reduce these footprints, and effectively precondition the data for amplitude studies. The CRS, or Common Reflection Surface method is essentially a multi-parameter stacking method that is used here to regularize and interpolate the data in one step. A regular coverage in CMP-offset-azimuth is thus achieved in most part of the data. Subsequent azimuth-dependent prestack time migration provides high resolution images at low migration noise, with strongly reduced footprints and well-preserved amplitude trends as a basis for subsequent amplitude studies.