Molecular Simulation of CO2 Solubility and Its Effect on Octane Swelling

Carbon dioxide (CO 2 ) flooding is one of the very important industrial processes for enhanced hydrocarbon recovery. Therefore, a better understanding of the CO 2 solubility and its effect on hydrocarbon swelling is vital for a successful CO 2 flooding project. In this study, CO 2 solubility in octane and its effect on octane ( n -octane) swelling are investigated by performing configurational-bias Monte Carlo simulations in the osmotic ensemble at two temperatures of 323 and 353 K and a pressure range of 2–10 MPa. This study provides a quantitative understanding of the relationship between the CO 2 solubility and the octane density reduction/swelling. The simulated swelling factor of the CO 2 saturated octane is linearly correlated to the CO 2 solubility. The results are in good agreement with the linear correlation derived from the published experimental data. Our results have also indicated that the interaction between the octane and CO 2 is the main cause of the octane swelling. Molecular modeling proves to be a valuable tool for the calculation of gas solubility in the hydrocarbon and its effect on the swelling factor, and this method is applicable to a wide range of gas-oil systems.