Numerical study on pressure variation due to subsurface CO2 injection

Anthropogenic emissions of carbon dioxide (CO2) is accelerating global warming. To resolve the CO2 emission problem, geologic storage of CO2 is being considered as the most likely option. In order to implement this technology, it is essential to understand the physical and chemical characteristics of CO2 in deep subsurface environment. Numerical simulations were performed with the use of TOUGH2 simulator to assess the pressure evolution with CO2 injection and the parameters that affect the CO2 behavior. This study focused on the effects of location of injection interval, regional flow system, and layer tilting. Injection of CO2 to the upper part of the aquifer caused low efficiency of storage due to buoyancy effect. The CO2 injected into deep saline aquifer was slightly affected by regional flow system, while CO2 movement was relatively sensitive to layer tilting.