3-D prestack depth migration by wavefield extrapolation methods

Abstract

After a decade in which Kirchhoff migration has been the workhorse method for structural imaging, the industry has found that this method fails to image the most structurally challenging geology. Wavefield extrapolation based approaches have shown promise in complex structural imaging, but many of their assumed advantages have been found inadequate. In this paper, we review the progress made by these approaches, and we survey various implementations that are available. We also review several key issues that are critical if the wavefield extrapolation approach is to be useful in generating high-fidelity production-scale images. Some of these issues include: true amplitude formulation, imaging condition aliasing, sail line aliasing, and angle-gather computation. We use results from both synthetic and real data to illustrate the advantages and challenges facing wavefield extrapolation based migrations.