The impact of brine production on aquifer storage of captured CO2

Abstract

This project aimed to assess the potential for brine production through dedicated wells in target Carbon Dioxide (CO2) storage formations to increase CO2 storage capacity and reduce overall cost of storage - as well as any other potential benefits for CO2 store operators associated with brine production. Brine production is proposed as a method to manage pressure in storage sites, as a corollary to water injection during hydrocarbon extraction. In the case of CO2 storage, the concept is that the production of water creates voidage to increase storage capacity and reduce the extent of pressure increase due to CO2 injection. This in turn reduces the risk of caprock failure, fault reactivation and induced seismicity. Additionally, brine production reduces the energy available to drive fluids through legacy well paths and other potential seep features. Spatial reduction in the extent of the pressure plume cuts down the area of potential drilling interference, the number of impacted legacy wells, and the area of investigation for monitoring where brine movement is a concern. This report presents findings from the entire project, and references other project reports where appropriate.