Storage capacity enhancement and reservoir management using water extraction: Four site case studies

Water extraction from carbon dioxide (CO2) storage reservoirs may be a method to enhance storage capacity and to actively manage storage reservoirs. Previous investigations into the use of water extraction have utilized homogeneous models to assess the feasibility of this technology. This study addressed water extraction based on four hypothetical CO2 storage sites, which varied with respect to heterogeneous lithology, variable structure, and complex internal geometry. The simulation results showed the increased CO2 storage capacity achieved through the use of water extraction varies greatly based on site conditions, ranging from 4% to 1300% in the four cases investigated. In all scenarios, water extraction reduced the maximum reservoir pressures approximately 10-20% during injection. In most scenarios, CO2 plume movement could also be influenced through the use of water extraction. The last two aspects may be very beneficial for risk management and monitoring, verification, and accounting practices for all of the CO2 storage projects.