THE GEOLOGY AND HYDROCARBON IN PLACE ESTIMATE AT SB3-SB4 INTERVAL, MELIAT FORMATION, AD FIELD, TARAKAN SUB-BASIN, TARAKAN BASIN

• Main Author: Difi, Audrey
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/53820
• Institution: Institut Teknologi Bandung

AD Field is an onshore gas field located in the Tarakan Basin, North Kalimantan with an area of 84 km2. This study was conducted at the interval SB3-SB4, which is located in the Middle Miocene Meliat Formation, and aims to understand the subsurface geologic configuration of AD Field and estimate the hydrocarbon in place within the study interval. The data used in this study include well data, i.e. side wall core descriptions, wireline logs, cuttings descriptions, thin section photos and descriptions, checkshots, biostratigraphy and drill stem tests, as well as 22 two-dimensional seismic lines. The data were analysed through facies and depositional environment analysis, sequence stratigraphic analysis, petrophysical analysis, seismic interpretation and hydrocarbon in place estimation through volumetric calculation. Seismic interpretation shows two normal faults and three anticlines within the borders of AD Field. Eight lithofacies, ranging from sandstones, siltstones and claystones to coals, are identified through facies and depositional environment analysis which, after matched with their corresponding electrofacies, are grouped into three facies associations: interdistributary plain, distributary channel and delta front bar of a deltaic transitional environment with tidal influence. Sequence stratigraphic analysis shows sediment thickening eastward with a generally prograding pattern. Petrophysical analysis provides cut-off values for shale volume at 0.50, effective porosity at 0.06 and water saturation at 0.55, showing two potential reservoirs, both of which are distributary channel deposits. Hydrocarbon in place estimation puts the two reservoirs at 2.61 BSCF.