MULTIATTRIBUTE SEISMIC ANALYSIS FOR MAPPING SANDSTONE RESERVOIR IN “ZEN” FIELD, LOWER TALANG AKAR FORMATION, SOUTH SUMATERA BASIN

• Main Author: Yusuf Hartono, Zenieth
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/69166
• Institution: Institut Teknologi Bandung

The oil and gas sector plays an important role in maintaining economic and energy stability in Indonesia. SKK Migas targets upstream oil and gas production of one million BOPD of oil and 12 billion SCFD of gas by 2030. In order to support this target, it is necessary to develop oil and gas fields in Indonesia, one of which is by reservoir characterization. One of these developments is in the "ZEN" Field which is an oil and gas field located in the South Sumatra Basin with the main target of sandstone reservoirs in the Lower Talang Akar Formation which is divided into four target zone intervals (Upper LTAF, Middle LTAF, Lower LTAF, Simpang LTAF). The purpose of this study was to determine the distribution of sandstone reservoirs and their deposition environments as well as recommendations for development well locations using 3D PSTM seismic data and 64 wells. The sandstone reservoir in the "ZEN" Field has coal and shale in it so that causes ambiguity in seismic records. In addition, the "ZEN" field is also divided into three compartments due to faults. Therefore, a sensitive parameter is needed to map and distinguish sandstone reservoirs from other lithologies. Based on the characteristics and results of sensitivity analysis by crossploting acoustic impedance (AI) and density log data, it shows that density can distinguish sandstone reservoirs and other lithologies with different sandstone reservoir cutoff values at each interval. Therefore, the effective method used in this study is multiatribute seismic with attribute external inputs in the form of acoustic impedance inversions used to predict the distribution of sandstone reservoirs in the "ZEN" field. After that, slicing is carried out at each interval to obtain the distribution of density values laterally. Then the location of the new development well is determined by making a hydrocarbon contact map from the density map with the depth contours of the location selected with a consistent distribution of sandstone and hydracarbon at each interval.