Application of three-component VSP technology at seismically difficult sites: An example from the FutureGen 2.0 site, Morgan County, Illinois, USA

Abstract Reflection seismic data provide the primary technology for imaging subsurface geology between and distal to wellbores; and where rock physics properties are suitable, surface seismic and vertical seismic profiles (VSP's) can provide important CCUS monitoring modalities. In addition, seismic data provide the subsurface framework for locating microseismic events and reducing risk of induced seismicity. Seismic surveys have traditionally been limited to acquisition and processing of compressional (P) -wave data, but modern technology includes the use of three-component receivers that can additionally record shear (S) wave modes that have been generated at the surface or converted from P-waves in the subsurface. Each collected waveform can potentially produce a separate data volume and new information on the subsurface. This paper reviews the insights gained through application of multicomponent VSP technology at the FutureGen2.0 site where, typical of many proposed CCUS and CCS sites, traditional P- wave surface seismic imaging is considerably impacted by seismic noise. We conclude that a comparison of shear and P-wave data and interferometric processing allows a better understanding of subsurface geology, and provides input parameters for improved acquisition of surface seismic data at CCUS sites in old, fast rocks or below depleted oil and gas fields. Although results will vary by locality, we suggest that because of the insights provided by an analysis of multicomponent data, multicomponent acquisition and processing should become part of standard best practices for site characterization and evaluation.