Computer modelling of the effect of carbon dioxide and pentane as solvents combined with in-situ combustion on the recovery of heavy oil

In-situ combustion (ISC) has proven, under some circumstances, to be effective in heavy oil recovery. Carbon dioxide (CO2) injection also has proven to be a potentially important heavy oil recovery method (Issever & Topkaya, 1998). In this research, computer simulations were performed to investigate the effect of carbon dioxide injection when combined with in situ combustion during heavy oil recovery. The Eclipse 300 reservoir simulator was used to develop laboratory and field scale simulations of ISC. The laboratory scale simulator was validated with published laboratory results. The West Heidelberg field was used to validate the field scale model. Then a simulation that combined CO2 injection with the in-situ combustion process was run to determine whether the combination would result in additional oil production. An additional simulation using pentane, another hydrocarbon solvent, combined with in-situ combustion was also performed. Pentane was used because it has a higher solubility in oil. The amount of oil recovered from all three cases was compared.;The results indicate that CO2 injection before ISC slightly increased the total amount of heavy oil recovered when compared to the ISC process only. The injection of pentane with ISC also showed an increase in the amount of heavy oil recovered when compared to the ISC-only process.