Modeling CO2 Circulation Test for Sustainable Geothermal Power Generation at the Aquistore CO2 Storage Site, Saskatchewan, Canada

Summary Over the past decade, geological storage of CO2, mostly in deep saline aquifers, has demonstrated a practical short-to-medium term means to partially meet the ambitious global commitments to climate change mitigation and net-zero carbon emission policies. As a key element of CO2 Plume Geothermal (CPG) systems, we examine the feasibility of running a CO2 circulation test utilizing an existing underground CO2 plume for synergistic utilization of the Aquistore site for both subsurface CO2 storage and geothermal power generation. In this work, we appraised the most probable realizations of CO2 plume extent from history matched numerical simulations and time-lapse seismic monitoring. We extracted and re-built a high-resolution sector model from a developed full geological model to represent the geology near the existing injection and observation wells. Given the extensive field evidence of CO2 arrival at the observation well, we performed uncertainty assessment of a CO2 circulation pilot test between the injector and the producer (i.e. observation well), followed by assessment of the resulting flow regimes during CO2/brine co-production. The findings of this paper assist in identifying the potential and limitations associated with conducting a CO2 circulation test and ultimately CPG operations at geologic CO2 storage sites such as Aquistore.