Improving the Image Below Complex Overburden Geology with FWI and Q-tomography: A Case Study at Etame License Area, Offshore Gabon

Summary

This paper discusses a velocity model building and imaging case study on a multi-azimuth towed streamer survey over the Etame license area in offshore Gabon. The model building and imaging strategy features refraction and reflection full waveform inversion (FWI), Q-tomography and Q-migrations (Q-RTM and Q-Kirchhoff PSDM). In combination with 3D deghosted input seismic data, we present the generation of accurate, high resolution and geologically consistent velocity models. In the presence of geophysical and geologic challenges, we show the workflow and techniques significantly improve the overall seismic image and the pre-salt targets which revives the oil development field.