Hydraulic controls on injection of carbon dioxide into deep saline aquifers

Sequestration of carbon dioxide in geologic formations, both deep aquifers and depleted petroleum reservoirs, has the potential to signi...cantly reduce the atmospheric emissions of that greenhouse gas. Injection into a deep saline formation di¤ers from injection into a hydrocarbon reservoir in that there is no produced ‡uid from the aquifer and the hydrogeologic characterization of both the receptor formation and the cap or seal is much more uncertain. Hydraulic control may reduce the risks and increase the safety of CO2 sequestration. While the applicability to a particular site is strongly dependent on the local conditions, the injection of brine above the con...ning layer can reduce the vertical migration and enhance the lateral spreading of the carbon dioxide.