An Investigation into the Enhancement of Condensate Recovery from Retrograde Gas Condensate Reservoirs

Abstract

The loss in condensate recovery from gas condensate reservoirs due to condensate dropout when the flowing bottom hole pressure drops below the dew point pressure of the in-situ reservoir fluid is significant. Pressure maintenance and gas cycling are the standard practices used to alleviate this problem and enhance the condensate and gas recoveries.
In this study, swelling and constant volume depletion tests are conducted on the original fluid sample from a gas condensate reservoir. Various scenarios regarding gas injection recycling are examined to determine the most appropriate gas for injection which enhances gas and condensate recovery. In this study, injection of three gases (CO2, N2 and separator gas) with different injection volumes on the current field fluid were tested using simulation.
Based on the results of this study, CO2 was the most efficient gas followed by separator gas and N2 respectively to inject into the gas condensate reservoirs for decreasing the condensate dropout and enhancing its recovery.
This result is significant as CO2 injection in gas condensate reservoirs could be used to sequestrate the produced CO2 from power plants and other sources while enhancing the production from gas condensate reservoirs.