Offsetting Water Requirements and Stress with Enhanced Water Recovery from CO<sub>2</sub> Storage

Abstract

Carbon dioxide (CO2) capture, utilization, and storage (CCUS) operations ultimately require injecting and storing CO2 into deep saline aquifers. Reservoir pressure typically rises as CO2 is injected increasing the cost and risk of CCUS and decreasing viable storage within the formation. Active management of the reservoir pressure through the extraction of brine can reduce the pressurization while providing a number of benefits including increased storage capacity for CO2, reduced risks linked to reservoir overpressure, and CO2 plume management. Through enhanced water recovery (EWR), brine within the saline aquifer can be extracted and treated through desalination technologies which could be used to offset the water requirements for thermoelectric power plants or local water needs such as agriculture, or produce a marketable such as lithium through mineral extraction. This paper discusses modeled scenarios of CO2 injection into the Rock Springs Uplift (RSU) formation in Wyoming with EWR. The Finite Element Heat and Mass Transfer Code (FEHM), developed by Los Alamos National Laboratory (LANL), was used to model CO2 injection with brine extraction and the corresponding pressure tradeoffs. Scenarios were compared in order to analyze how pressure management through the quantity and location of brine extraction wells can increase CO2 storage capacity andmore » brine extraction while reducing risks associated with over pressurization. Future research will couple a cost-benefit analysis to these simulations in order to determine if the benefit of subsurface pressure management and increase CO2 storage capacity can outweigh multiple extraction wells with increased cost of installation and maintenance as well as treatment and/or disposal of the extracted brine.« less