PETROPHYSICAL ANALYSIS OF COAL GAS METHANE CALCULATION IN THE "ALPHA" FIELD, MUARA ENIM FORMATION, SOUTH SUMATERA BASIN

• Main Author: Hafriandy, Erry
• Format: Theses
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/78488
• Institution: Institut Teknologi Bandung

Coal gas methane or better known as Coal Bed Methane (CBM) is currently one of the alternative energy that are designated to reduce oil and gas consumption nationally. The advantage of taking this energy is its environmentally friendly behaviour. This study was conducted to determine the gas content in coal, that are produced from two types data, such as surface data (coal sample) and gas calculations which generated from well logs. The research areas ("Alpha" Field) is located in the Sub-Basin of the South Palembang, South Sumatera Basin. Based on electrofacies analysis, coal in the research area is generally deposited in the deltaic environment. In order to get the coal seams beneath the surface, petrophysical parameters such as density values (RHOB) less than or equal to 1.4 g / cc, is used. In addition, other values used is gamma ray parameter with a value between 90-120 API. Types of coal can be determined by plotting the value of density (RHOB), neutron porosity (NPHI), and sonic (DT). Gas content is calculated by using Kim Formula that is performed for surface data and data from well log analysis. Based on chart NPHI vs RHOB and RHOB vs DT, coal in the study area is divided into two types, they are sub-bituminous and bituminous. Coal matrix density value that be used in calculating gas content is about 1.26 to 1.29 g / cc (generated from the average RHAMACA value). The results of the comparison showed that the gas content from the petrophysical analysis is greater than that calculated from the surface data. The petrophysical analysis result Erry Hafriandy 22009019 iv value of gas produced at 140-160 SCF / Ton, while laboratory analysis data produced gas value of 73-91 SCF / Ton.