Wide-azimuth Tomography - Strategy and Application

Over the past three years, wide-azimuth towed-streamer acquisition (WATS) has become a major step improvement in marine acquisition technology for better imaging of complex subsalt structures in the Gulf of Mexico. However, wide-azimuth seismic acquisition, with shot and receiver locations covering a large portion of the two dimensional surface, presents a new challenge for tomography in deriving an accurate velocity model. A strategy for wide-azimuth tomography is proposed, and the benefit of vector-offset domain tomography over azimuth-angle domain tomography is discussed. Wide-azimuth tomography results from marine and land data are presented and are compared to narrow-azimuth tomography results. These case studies both demonstrate the advantage of wide-azimuth tomography over narrow-azimuth tomography.