Investigating the Effectiveness of Gas Re-Cycling for Improved Condensate Recovery in Gas Condensate Reservoirs: A Field Case Study

Abstract The productivity of a condensate reservoir in the Niger-delta region of Nigeria is declining. The initial production rates for oil and gas were reported to be 350 barrels per day and 1.2 million standard cubic feet per day, respectively. This poses a unique difficulty for reservoir operators in determining the most effective way to optimize recovery. In this study, we use the CMG reservoir simulator to analyze the effects of gas recycling on the recovery of condensate and gas in a typical gas-condensate reservoir. The aim of our study is to assess the effectiveness of gas recycling in improving the overall recovery of hydrocarbons while keeping the pressure in the reservoir stable. We employed the gas recycling approach by employing the same well for injection, instead of drilling a new well, and compared its performance to a baseline scenario without gas recycling. The findings demonstrate that the process of gas recycling has a substantial positive impact on the rates of condensate and gas recovery. In comparison to the baseline scenario, our gas injection resulted in a significant increase in condensate recovery, around 100 barrels per day, which accounted for the whole amount of condensate being produced at that time. In a similar manner, the gas recovery increased by about 1 million cubic feet per day, reaching a level where it accounted for more than 70% of the gas being generated. The gas injection pattern showed enhancements, however it necessitated greater injection rates due to the failure to achieve early recovery levels. Finally, the well's downhole pressure was greatly boosted, although this did not result in the best possible recovery performance. This study indicates that gas recycling shows great potential for improving the extraction of hydrocarbons in gas-condensate reservoirs. By utilizing sophisticated reservoir simulation models such as CMG, we can enhance our ability to forecast the results of different gas recycling schemes and steer decision-making towards more sustainable and economically feasible development strategies.