FWI imaging: Revealing the unprecedented resolution of seismic data

Abstract

Although the resolution of a seismic image is ultimately bound by the spatial and temporal sampling of the acquired seismic data, the seismic images obtained through conventional imaging methods normally fall far short of this limit. In addition to attenuation in the Earth, factors such as velocity errors, illumination holes, residual noise and multiples, source and receiver ghost notches, and migration swings can prevent conventional imaging methods from obtaining a high-resolution image of good signal-to-noise ratio (S/N) and well-focused details as promised by the maximum migration frequency. Recently, FWI Imaging, which uses the full-wavefield data to iteratively invert for the reflectivity together with velocity through full-waveform inversion (FWI), has shown to be a superior method for providing seismic images of greatly improved illumination, S/N, focusing, and thus better resolution, over conventional imaging methods. Here, we push FWI Imaging to a frequency close to the temporal resolution limit of seismic data (100 Hz) and demonstrate that FWI Imaging at a very high frequency can provide seismic images of unprecedented resolution from the recorded data, which has been impossible to achieve by other seismic imaging approaches.