Publications

One of the recent developments in prestack seismic imaging is the application of full-waveform inversion (FWI) to velocity model building and updating. The FWI technique computes the difference between synthetic waveforms generated from the initial P-wave velocity (Vp) model and the actual recorded (observed) data and then back-propagates the difference to update the Vp model. It achieves convergence when the difference between the two datasets is minimized. The inversion proceeds from lower to higher frequencies to obtain global convergence before updating the localized velocity trend. Therefore, very low-frequency signal plays a critical role in the success of FWI processing. In the marine environment, seismic data acquisition using a slanted streamer technique (i.e., the streamer is towed at varying depths) provides more low-frequency signal than with a conventional method. In this study, FWI processing of two differently acquired datasets from a shallow-water test survey in Asia provides the opportunity to analyze the benefit of the additional low frequency signal and compare the processed results from a constant gradient slanted streamer data and constant depth streamer data. Both datasets underwent similar processing except for cable deghosting. The application of acoustic anisotropic FWI to constant gradient slanted streamer data produced a more geologically plausible velocity model and image with better stack continuity and simpler geological structure than that produced in the conventional 8m depth flat streamer data. Keywords: FWI, slanted streamer, deghosting