Offset VSP for the Reservoir Monitoring

Abstract

Summary Offset Vertical Seismic Profile (VSP) is often used for time-lapse seismic monitoring in oil/gas exploration or CO2 geosequestration. Standard offset VSP processing technologies allow the imaging and qualitative interpretation of time-lapse changes in the medium. However, quantification of the observed time-lapse anomalies is often needed. We suggest using Full Waveform Inversion (FWI) for quantitative interpretation of the offset VSP data. We apply conventional time-lapse processing and time-lapse FWI to the offset VSP dataset acquired in the Otway field and compare the results. We observe a match in the images of the CO2 plume obtained by both methods and suggest that using FWI increases the value of offset VSP data.