A parametric investigation of the cyclic CO2 injection process

The influences of important process and reservoir parameters on the cyclic CO2 injection process were investigated. The parameters examined included gravity segregation, remaining oil saturation, reservoir dip, the presence of a gas cap, and the use of a drive gas. Experiments were performed in Berea Sandstone cores using a light crude oil from the Timbalier Bay field. y segregation, the presence of a gas cap, and a higher remaining oil saturation improved process performance. Oil recovery efficiencies and gas utilization factors were affected by the inclination of the core and the site of injection. Process performance was benefitted when CO2 was injected into the lower end of a core tilted at an angle of 45 ° or more. A poorer response was obtained when the core was horizontal or when CO2 was injected into the top of a tilted core. e of a nitrogen drive (or chase) gas dramatically boosted oil recovery as compared to injection of the same mass of CO2 alone. Over twice as much oil was recovered by the first cycle injection of CO2 followed by nitrogen as compared to first cycle injection of that mass of CO2 alone. The second injection cycle of the drive gas experiment recovered over three times as much oil as recovered by a second cycle injection of that mass of CO2 alone.