Monitoring and imaging of active and passive CO₂ seepage patterns

The uncertainty in the safety of CO2 storage is directly linked to the understanding of potential seepage or leakage along faults or fracture zones within a storage complex. To study this phenomenon, we investigate natural CO2 leakage along the Little Grand Wash Fault (Utah, USA). Current surface flow and former seep patterns have been identified and analyzed in light of guiding deformation structures, stacked reservoir-seal systems, diagenetic status and rock strength. Preliminary active source seismic lines have been conducted at the site, including time-lapse seismics of CO2-migration events, which will be complemented with passive seismic observations in 2021. This study describes the preparation phase and first results of a multidisciplinary study including geological, geomechanical and active & passive seismic investigations.