The effect of argon contamination on interfacial tension, diffusion coefficients and storage capacity in carbon sequestration processes

In order to evaluate the risk of CO2 diffusion loss through a cap rock, we measured the diffusion coefficients of geological water in the injected fluid. It was found that the diffusion coefficients of water in Ar are higher in comparison to those of water in CO2. Small quantities of salt in water had a minor effect on the diffusion coefficients of brine in supercritical CO2. Experimentally obtained diffusion coefficients (Dab) were correlated to obtain the effective diffusion coefficient (Deff). It was found that, in the case of co-injection of Ar with CO2, the diffusive gas breakthrough could be enhanced.