Seismic Monitoring at the Farnsworth CO2-EOR Field Using Time-Lapse Elastic-Waveform Inversion of 3D-3C VSP Data

During the Development Phase of U.S. Southwest Regional Partnership on Carbon Sequestration, supercritical CO2 was continuously injected into deep oil-bearing Morrow B formation Farnsworth Unit in Texas for Enhanced Oil Recovery (EOR). The project approximately 94 kilotons to study geologic carbon storage during CO2-EOR. A three-dimensional (3D) surface seismic dataset acquired 2013 characterize subsurface structures site. Following this data acquisition, baseline and three time-lapse three-component (3D-3C) vertical profiling (VSP) were at a narrower area surrounding injection oil/gas production wells between 2014 2017 monitoring migration. With these VSP datasets, we inverted velocity models quantitatively monitor plume within formation. We first built 1D initial P-wave (Vp) S-wave (Vs) by upscaling sonic logs. improved region Vp Vs incorporating part migration model derived from 3D data. shallow using traveltime tomography arrivals downgoing waves. further elastic-waveform inversion (EWI) upgoing Our advanced EWI method employs alternative tomographic conventional gradients total-variation-based regularization ensure high-fidelity updates models. then sequentially applied our datasets invert spatiotemporal changes reservoir. results reveal volumetric show evolution well wells.