Publications

Time-lapse microgravity method is the development of the gravity method (x, y, z) by adding a fourth dimension of time (t). Time-lapse microgravity is used for monitoring fluid movement in Sumatran fields. Monitoring is carried out on production fields where Enhanced Oil Recovery (EOR) is practiced. EOR is the process of injecting water into the reservoir to push and drain the remains of oil in the pores of the reservoir rock to the production well. The microgravity data processing is performed by finding the difference between observed gravity values between the first and the second measurements and then performing the spectral analysis to separate the anomaly at reservoir depth and noise. The time-lapse microgravity anomaly has a value of -132 μGal to 54 μGal. Positive anomalies are related to the injection process, whereas the negative anomalies are related to the production process in the study area. Filtering analysis shows that there are two zones of fluid dynamics one which is due to the process of surface water dynamics (groundwater above reservoir) and one that occurs in the reservoir. Fluid reduction zones occur in areas with more production wells than injection wells. Density reduction occurs in the reservoir layer at a depth of 600 m to 1000 m with a maximum reduction value of -3.1x10 gr/cm3.