Anisotropic Earth Model Building Using Multi-survey Full Waveform Inversion with Ocean-bottom Cable and Streamer Data

On the Norwegian continental shelf in the southern part of the Utsira High area, the reservoir is highly altered and fractured, and seismic image quality is strongly affected by overburden complex velocity contrasts. Resolving these overburden effects is critical for correctly positioning the deeper section to improve the image at the reservoir level. Here, we demonstrate a full waveform inversion (FWI) workflow with multi-survey inputs to obtain a superior anisotropic velocity model by simultaneously minimizing the difference between all observed and modelled data. The data in this case are an ocean-bottom cable survey and two towed streamer surveys. Here we utilized two new functionalities within our FWI implementation. First we simultaneously inverted a single earth model using FWI with all multi-survey inputs. Secondly, we adopted a hierarchical multi-parameter strategy to invert for anisotropic parameters using FWI. This workflow takes advantage of all data to add more constraints to the inversion process to explain all acquired surface seismic data. The anisotropic earth model not only benefits the imaging process to reduce the uncertainties at the reservoir level, but also provides a high quality reservoir product that guides interpretation and AVO inversion.