A Novel Correlation on MMP Prediction in CO2-LPG Injection System: A Case Study of Field X in Indonesia

In order to increase Indonesia’s petroleum production, which mostly comes from the marginal field, an Enhanced Oil Recovery (EOR) method is needed. One EOR method that is proven to be able to increase large oil yield is mixed CO2 injection. In implementing EOR CO2 injection mixed, the Minimum Reliability Pressure (MMP) value is the key to success. One of the problems faced by oil fields in Indonesia in carrying out EOR of mixed CO2 injection is that the reservoir pressure has dropped due to old age making it difficult to inject with MMP pressure above the reservoir pressure. The solution that can be done to overcome this is by reducing the MMP value using Liquified Petroleum Gas (LPG).This study will determine the optimal method of LPG use to reduce CO2 injection MMP values from Field X fluid in South Sumatra. Then, the MMP value in various conditions will be determined using a slimtube simulation which will be used to make a correlation to determine the MMP value. From the results of the study, in principle mixing LPG with CO2 will reduce the MMP value optimally. In addition, the average MMP value dropped by 29.5% with an increase in the composition of LPG in the gas mixture of CO2 LPG injection by 30%, the MMP value increased by 23% with a change in hexane plus molecular weight of 27.5% higher than before, and the MMP value increased by an average of 13.4% with an increase in temperature of 20%.The resulting correlation is formed using parameters that have a significant influence on the determination of the MMP value. The resulting correlation has R-Squared of 98.65%. The correlation is then tested with MMP values previously determined through a slimtube simulation and produces an Average Absolute Relative Error (AARE) value of 4.52%. Correlation was then re-tested against the correlations of other MMP determinations using 9 fluid MMP data from other literature. The result is the proposed correlation produces an AARE value of 10.82%.