OPTIMALISASI PRODUKSI MINYAK DENGAN STRATEGI REAKTIVASI SUMUR PRODUKSI DAN INJEKSI AIR PADA LAPANGAN Z

Abstract

This study evaluates the remaining production potential of the mature Z Field through an integrated approach using Material Balance (MBAL), Decline Curve Analysis (DCA), and injector performance evaluation. The MBAL analysis indicates that the Z Field contains an Original Oil in Place (OOIP) of 52.85 MMSTB and is characterized by a combined drive mechanism, with solution gas drive dominating the early production stage and supported by water injection drive during the later stage. Production forecasting using an economic limit of 25 BOPD yields an Estimated Ultimate Recovery (EUR) of 12.17 MMSTB for the six-well reactivation scenario, which increases to 15.90 MMSTB with the addition of three production wells, resulting in an improvement of recovery factor from 24.05% to 30.09%. Exponential DCA applied to six reactivated wells estimates an aggregate EUR of 2.72 MMSTB, corresponding to a recovery factor of approximately 5.14% of the field OOIP, and identifies wells ZELE-01, ZELA-06, and ZELA-02 as the highest-priority candidates based on remaining recoverable volumes. Injector performance analysis using Voidage Replacement Ratio, Chan Plot, and Hall Plot demonstrates that water injection contributes to reservoir pressure maintenance, although its effectiveness varies spatially and temporally, thereby supporting the combined drive interpretation and providing a realistic assessment of the opportunities and limitations of well reactivation in the Z Field.