PENENTUAN ZONA PROSPEK PADA KERJA ULANG PINDAH LAPISAN DENGAN ANALISIS LOG PADA LAPANGAN “X” SUMUR “T”

Field X is located in West Java province, which is in the northern part of the West Java Basin which is included in the working area of PT Pertamina EP Asset 3 Tambun Field. In line with the addition of time and production process, the amount of water produced will increase, while the production of oil and das decreases in line with decreasing pressure from time to time. The value of WC (Water cut) in field X has reached 95%. To optimize the production of hydrocarbons, it is necessary to carry out KUPL (Switching Layers Rework). This research aims to determine the prospect zone in the reservoir formation on field X which has not been produced yet. The method used is the collection of log data, petrophysical data, and production data. Next, do data processing, namely lithology identification, log normalization and clay type identification. After processing the data, the interpretation is qualitative and quantitative, and qualitative interpretation is done to determine the prospect zone. After that, the quantitative interpretation is carried out, the analysis uses petrophysical data which includes the calculation of shale volume, effective porosity, and water saturation. Lastly is to determine the zone for KUPL to do. Based on the results of the petrophysical analysis, the Vsh value was 0.28, the effective porosity was 0.19, the Sw value was 0.65. Based on the above considerations, KUPL was carried out in Field T of Reservoir Formation layer C which had a Net Pay thickness of 17ft, porosity of 0.19, shale volume of 0.42 and water saturation of 0.60. Based on economic calculation with break event point as well as net present value, the workover for this well is feasible to be performed. Keyword: hydrocarbon prospect, pay zone, petrofisics, workover, log analysi