The effect of temperature on CO2 injectivity in sandstone reservoirs

Abstract

Carbon Capture, Utilization and Storage (CCUS) is a pragmatic technology that could reduce anthropogenic CO2 and halt climate change. CO2 injectivity is affected by several physicochemical interactions around the injection area of the wellbore which are temperature-dependant. There is a thermal disequilibrium between the injected CO2 and the reservoir rock at the wellbore injection area which has not been thoroughly investigated. A pore-scale model was developed to predict the distance travelled by the injected fluid into the formation before thermal equilibrium is established. In the Snøhvit field where the wellhead injection temperature is 4 °C, it was found that the injected CO2 may attain supercritical state at bottomhole conditions, although a minimum temperature difference of about 40 °C may exist between the bottomhole fluid and the reservoir rock. Thermal equilibrium around the injection area was dependant on the wellhead injection temperature, the injection flow rate and reservoir shaliness.