Evaluation of carbon dioxide based Vapex process for recovery of heavy oil and bitumen

The main objectives of this research were to design and perform laboratory experiments to evaluate the potential of CO2 as Vapex solvent for the recovery of heavy oils and bitumen reservoirs. CO2 and propane mixtures were utilized as the injected solvents and compared to the currently popular mixtures of methane and propane. A new semi-scaled cylindrical model was designed and fabricated with steel and used to perform laboratory experiments. The influence of oil viscosity on the performance of the process was investigated by conducting experiments with two types of oil (4500 m.Pa.s & 18600 m.Pa.s at 21°C). These tests were performed at different operating pressures of 200, 250, 400 and 600 psig (1469, 1814, 2848 and 4227 KPa) and were designed to compare the performance of methane-based solvents with that of CO2 based solvents.; Results from these experiment show that at high operation pressure CO 2-propane mixture provided better performance in the Vapex process compared to the methanepropane mixture. Although there was no recovery or rate benefit at lower operating pressure, the lower cost of CO2 (if available) and the environmental benefits might be sufficient reasons for using CO 2-propane mixtures. (Abstract shortened by UMI.)...