Acoustic encoded full-waveform inversion method research in areas with a rugged surface

Abstract

Velocity estimation technique has always been the core issue of seismic exploration. Full waveform inversion (FWI) (Tarantola, 1984) is an effective method for reconstructing highly resolved models of the earth's velocity distribution. It can be implemented in either the space-frequency (Pratt et al., 1998) or the space time domains (Zhou et al., 1995). It more accurately estimates subsurface velocity estimation than conventional techniques do, especially in geologically complex areas. As for areas with a rugged surface, we proposed a velocity inversion method based on coordinate transform forward modeling and reverse-time migration method. The effect largely depends on the modeling techniques during inversion. In seismic inversion theory, migration imaging can be thought as one step of the process of inversion iteration. One step of FWI equals to the migration. In this paper, we first introduce coordinate transform finite difference forward modeling method, then we perform rugged surface reverse-time migration and velocity inversion. Tests with model and field data prove the correctness and effectiveness of our method.