HYDROCARBON RESERVOIR MODELING IN SB1-MFS2 INTERVAL, PUCANGAN FORMATION, SJ FIELD, NORTH EAST JAVA BASIN

• Main Author: Julianto, Seto
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/55310
• Institution: Institut Teknologi Bandung

The SJ field is an onshore hydrocarbon field located in the North East Java Basin, East Java Province, with an area of 2,7 km2. The study was conducted at the SB-1 - MFS-2 interval in SJ Field which is located in the Pleistocene Pucangan Formation. This study aims to study the geological setting of the SJ Field, study the SJ Field sequence stratigraphy, analyzing petrophysical analysis, modeling static reservoirs, and estimate the on-site hydrocarbon reserves at potential reservoir intervals in the SJ Field. The data used in this research are well data which include: wireline logging data, sidewell core descriptions, cutting core descriptions, checkshots, thin section photos and descriptions, drill stem test data, and seismic data in the form of 12 two-dimentional seismic line. The data is processed by analyzing facies and depositional environment, sequence stratigraphic analysis, petrophysical analysis, seismic interpretation, static reservoir modeling, and calculation of hydrocarbon in place estimation through volumetric calculations. Seismic interpretation shows a W-E trending anticline in SJ Field. Analysis of facies from core data and mudlog resulted in nine lithofacies consisting of claystone (Fcl1), carbonate claystone (Fcl2), siltstone (Fsl), fine sandstone (Fst1), medium sandstone (Fst2), cross-laminated medium sandstone (Fst3), coarse carbonaceous sandstones (Fst4), coarse sandstones (Fst5), and graded coarse sandstones (Fst6). These nine lithofacies are grouped into five facies associations, namely the interdistributary plain, fluvial distributary channel, tidal distributary channel, delta front bar, and prodelta based on delta facies model, in the tide-dominated delta environment. Then, facies association is matched with electrofacies to know the distribution of facies association at all wells. Sequence stratigraphy analysis shows 2 sequences, with study interval in the first sequence, in SB-1 – FS-1 parasequence within transgressive system tract deposit. Petrophysical analysis resulted in the average value on net-pay interval for the volume of shale at 0.32; effective porosity at 0.28; and the water saturation at 0.52. The application of the cut-off indicates one potential reservoir which is the sedimentation of the fluvial distributary channel and the tidal distributary channel. The estimated hydrocarbon in place produce gas of 2.83 BSCF.