Title: Joule-Thomson cooling of CO2 injected into aquifer under heat exchange with adjacent formations by Newtons law- 1D exact solution

Abstract: This paper discusses axi-symmetric flow during CO2 injection into a non-adiabatic reservoir accounting for Joule-Thomson cooling and steady-state heat exchange between the reservoir and the adjacent layers by Newtons law. An exact solution for this 1D problem is derived and a new method for model validation by comparison with quasi 2D analytical heat-conductivity solution is developed. The temperature profile obtained by the analytical solution shows a temperature decrease to a minimum value, followed by a sharp increase to initial reservoir temperature. The analytical model exhibits stabilization of the temperature profile and cooled zone. When accounting for heat gain from adjacent layers, the minimum temperature is higher compared to the case with no heat exchange. The analytical model can be used to evaluate the risks of hydrate formation and/or rock integrity during CO2 storage in depleted reservoirs.