Effects of reservoir temperature and percent levels of methane and ethane on CO2/Oil MMP values as determined using vanishing interfacial tension/capillary rise

摘要

The effects of reservoir temperature andpercent levels of methane and ethane in CO2 on the minimum miscibility pressures (MMPs) of crude oils were measured using a vanishing interfacial tension (VIT) method. MMPs increased linearly with methane concentrations but decreased when ethane was added to CO2. Higher reservoir temperatures yielded much higher MMPs for the same oil, apparently because of the reduction in CO2 densities that occur with increasing temperature. Oil samples collected from the CO2-dominated mobile "miscible" phase demonstrated that higher pressures mobilized more oil regardless of MMP, and that CO2 preferentially mobilizes lighter hydrocarbons, especially at lower pressures.