Full Waveform Inversion in a Complex Geological Setting - A Narrow Azimuth Towed Streamer Case Study from the Barents Sea

Abstract

We apply Full Waveform Inversion (FWI) to narrow azimuth (NAZ) towed streamer data acquired in the Barents Sea. This study is over the Samson Dome region and the aim of the FWI is to resolve the velocity field, which is known for its geological and structural complexity in this area. The FWI result shows a spatial consistency that was unexpected from the standard 3D NAZ dataset and demonstrates the potential use of FWI velocity models in geological interpretation and shallow geohazard detection, even if the FWI result is effectively driven by the combination of velocity, anisotropy and density, rather than just P-wave velocity. Finally, as one would expect, the dramatic improvement in the accuracy and resolution of the velocity model gives rise to improved seismic imaging.

Resolving the fine-scale velocity structure of continental hyperextension at the Deep Galicia Margin using full-waveform inversion

“…Three-dimensional FWI has yielded impressive results on marine seismic datasets, producing high resolution velocity models which can be used directly for geological interpretation or for the migration of reflection seismic data to produce detailed images (e.g. Sirgue et al 2010;Ratcliffe et al 2011;Warner et al 2013;Mispel et al 2013;Jones et al 2013;Mothi et al 2013). The vast majority of such studies have utilised seismic data recorded on either hydrophone streamers or ocean bottom cables (OBC), in relatively shallow marine environments (water depth < 1,000 m).…”

Extracting geologic information directly from high-resolution full-waveform inversion velocity models — A case study from offshore Trinidad

“…Figure 3 shows an interleaved comparison of the observed data with initial and final modeled shots from a good and poor data-quality region demonstrating an improved match with the real data. The output from FWI showed a mild sail-line-based footprint, which was attenuated by the use of a k filtering-based workflow (Jones et al, 2013). This footprint and attenuation technique is typical for streamer geometries and was applied to the whole of the survey and independently for the region around the Dolphin platform that used the orthogonal sail lines.…”

Using full waveform inversion to update supra-salt velocity models: A case study in the Gulf of Mexico

“…Wave-equation based FWI, pioneered by Lailly (1983) and Tarantola (1984), updates a velocity model by minimizing the mismatch between the observed and modeled seismic data. Studies have proven that FWI can provide detailed and interpretive velocity models, especially in the presence of shallow channel features and gas pockets (Sirgue et al, 2009;Jones et al, 2013;Ratcliffe et al, 2013;Mothi et al, 2013). In this study we applied FWI to resolve complex overburden velocities in a geologically challenging area where shallow geo-bodies, fractures and carapaces co-exist with shallow salt.…”