Imaging a CO2 Plume Over the Sleipner CCS Facility Using FWI of Sparse OBN Data

Sparse OBN acquisition can provide an efficient cost-effective method for acquiring seismic data over Carbon, Capture and Storage (CCS) sites. The authors demonstrate how using the full wavefield (P) data including surface multiple energy can enhance FWI imaging in the shallow subsurface greatly improving the suitability of such sparse node acquisition for CCS imaging. A data reconstruction FWI method is used to produce a high-resolution image of the CO2 plume and is compared to an FWI result obtained using reflectivity energy from OBN data processed through to up-down deconvolution (UDD). The velocity model derived using the UDD data suffers from poor illumination of the shallow subsurface resulting in anomalous events in the FWI image. Using the full wavefield provides an accurate, stable velocity model and image of the CO2 plume.