Hubungan Petrophysical Rock Typing dan Tekstur Sedimen Pada Zona Prospek Reservoir Formasi Talang Akar, Subcekungan Palembang Selatan, Cekungan Sumatera Selatan

Abstrak

The research area is in the South Palembang Subbasin, South Sumatra Basin is a petroleum producing area in Indonesia which is the working area of PT. Pertamina EP and Talang Akar Formation as the reservoir. This research aims to determine petrophysical parameters of reservoir and determine relationship between petrophysical rock typing and sedimentary texture in the reservoir prospect zone. The data used in this research are well logs data and well reports which contain temperature, RCAL, and XRD data. The data used to determine lithology are gamma ray logs and shale volume calculations use a linear method using gamma ray logs. Total and effective porosity data are calculated using density logs. Water saturation is calculated using the Simandoux method. The permeability value is determined using the porosity-permeability transform method. Rock typing was carried out using a hydraulic flow unit and Winland R35 method. Both methods use effective porosity and core permeability data. The values that have been obtained are cross plotted with shale volume and effective porosity to obtain rock type values. The hydraulic flow unit method produces 5 rock types, while the Winland R35 method produces 3 rock types. The reservoir potential zone has a shale volume value ≤ 0.3V/V, effective porosity ≥ 0.15V/V and water saturation ≥ 0.75V/V. Good petrophysical rock typing has a sediment texture in the form of fine sandstone and coarse sandstone grain sizes, good sorting, contact between grains in the form of points which causes the rock to have good porosity and permeability.