Sensitivity of Joule-Thomson cooling to impure CO2 injection in depleted gas reservoirs

The thermal risks associated with impure gas injection appear small. Enhanced cooling >5 K requires high-pressure, low-temperature injection in a low permeability reservoir and presence of O2, N2, and/or CH4 in the injectate. Co-injection of SO2 has clear beneficial thermal consequences for low-temperature injection, by suppressing Joule-Thomson cooling, and may therefore be of special interest to help bring down the costs of CO2 sequestration in depleted gas reservoirs.