Accelerating CO2 Solubility in Brine With Low Temperature Injection Scenario: Using a Downhole Cooling Tools

Different injection methods have been already proposed by different researchers to improve the solubility of CO2 in the formation brine. In this study an injection technique is presented to cool down (liquefy) the supercritical CO2 in the wellbore by the use of a downhole cooler equipment. The cold (liquefied) CO2 has a higher solubility in brine which improves the storage security. Additionally, higher density and viscosity of CO2 causes a higher viscous force and CO2 will sink to the formation and decreases the upwards movement of CO2 due to the buoyancy. With this method the supercritical CO2 is cooled down to a liquid phase to increase the solubility only at the wellbore and thus it eliminated the risk of phase change or pressure and rate fluctuation in liquid CO2 injection from the surface. Additionally the formation will have a lower pressure build-up because CO2 is more mixed with brine and remains less in the free gas phase