Above-zone temperature variations due to CO2 leakage from the storage aquifer

Above-zone temperature data can be acquired with high resolution and accuracy at low cost from which information on CO2 leakage may be inferred. CO2 injection in saline aquifers induces temperature changes due to processes including JT cooling, buoyancy-driven effects, endothermic water vaporization and exothermic CO2 dissolution, and temperature contrast between the injected CO2 and the native brine. CO2 leaking from the injection zone undergoes similar processes causing temperature changes in the overlying formations. We use numerical simulation tools to evaluate temperature changes associated with CO2 leakage from the storage aquifer to an overlying formation and assess the monitorability of CO2 leakage based on temperature data. We perform sensitivity analysis to determine the key operational and reservoir parameters that control the temperature signal.