Common-angle image gathers for shot-profile migration: an efficient and stable strategy

摘要

Shot-profile-based prestack depth migration is quite attractive for sparse-shot wide-azimuth geometries. Meanwhile, angle-domain common image gathers (ADCIGs) have become an essential tool in seismic processing (e.g. velocity analysis). In this paper, we first revisit the popular schemes of generating ADCIGs by wavefield continuation migration. Then we present an alternative approach to produce common-angle image gathers after shot-profile migration based on a one-way wave equation. The angle information is obtained from a division of two images: the conventional image and the angle-weighted image. The effects of sparse shot sampling on extracting ADCIGs have been investigated. Numerical results demonstrate that the described scheme is efficient and stable and can handle the problem of shot-aliasing well.