Assessing FWI Imaging’s potential to tackle illumination issues and internal multiples in the Brazilian pre-salt

Most seismic surveys carried out in offshore Brazil consist of narrow-azimuth towed-streamer (NATS) acquisitions. In areas such as the South Atlantic offshore basins, the geological complexity results in illumination issues for NATS acquisitions, especially in the deep pre-salt section. Both Full-Waveform Inversion Imaging (FWI Imaging) and Least-Squares RTM (LSRTM) can be used to tackle this issue. Furthermore, internal multiples are a common problem. When coupled with inhomogeneous illumination, these can cause strong distortions to the geological structures and render seismic images uninterpretable. Using a data set covering a complex salt mini-basin in Campos basin, we demonstrate the capacity of FWI Imaging to naturally alleviate distortions associated with internal multiples and illumination issues. We also compare it to LSRTM and highlight some of the differences.