Full wavefield data that includes transmitted waves, primary reflections, and their multiples, has been widely used for velocity model building through full-waveform inversion (FWI). However, migrating full wavefield data to image the subsurface remains very challenging. Higher order scattering energy potentially helps infill illumination holes of primary reflections, but it also introduces crosstalk noise into the migration image when imaging algorithms cannot properly handle this higher order scattering energy. With the advancement of high-performance computing and progress in FWI algorithms to tackle problems such as cycle-skipping and amplitude mismatch, FWI has found success using different data types in a variety of geologic settings. Here we take a step further to modify the FWI workflow to output the subsurface image or reflectivity directly, eliminating the need to go through the time-consuming seismic imaging process that involves preprocessing, velocity model building, and migration. Compared with a conventional reverse-time migration image, the reflectivity image directly output from FWI provides additional structural information with more balanced illumination, since FWI by nature is a least-squares fitting process of the full wavefield data.
This paper was accepted into the Technical Program but was not presented at the 2020 SEG Annual Meeting.
