Publications

Asem-Asem Basin is an Indonesian Tertiary basin with indications of large coal bed methane (CBM) potential. The objective of this preliminary study is to evaluate coal bed methane potential in the Jorong-Kintap Area. Analysis and integration of surface and subsurface data were used to estimate potential CBM resource of the area. The main coal bearing formations of Jorong-Kintap area are Warukin Formation of Miocene age and Tanjung Formation of Eocene age. The total thickness of Miocene coals in Warukin Formation is approximately 49 meters and the total thickness of Eocene coals in Tanjung Formation is approximately 6.1 meters. The coal continuity of both Formations is interpreted using markers identified from well data. Several coal samples from Jorong area were collected for labratory analysis. Proximate analysis of Miocene coals of Warukin Formation contain total moisture (TM) 27.35 %, ash 2.85 %, volatile matter (VM) 40.96%, fixed carbon (FC) 37.44%, calorific value (CV) 5492.6 cal/gram, Ro 0.31%, maceral composition is dominated by 82.8% of vitrinite, is classified as lignite (ASTM standard). The proximate analysis of Eocene coals of Tanjung Formation, contain total moisture (TM) 6.12%, ash 11.53 %, volatile matter (VM) 43.49 %, fixed carbon (FC) 39.6%, calorific value (CV) 6489 cal/gram, Ro 0.46%, maceral composition is dominated by 78.4% of vitrinite, is classified as Sub-Bituminous B (ASTM standard). Based on the proximate data, Kim’s Formula (1977) is applied to estimate the gas content of both formations. The gas content of Miocene coals of * PT. Sugico Warukin Formation at an optimum depth 300 to 1000 meters is approximately 78.39 scf/ton. The gas content of Eocene coals of Tanjung Formation at an optimum depth 300 to 1000 meters is approximately 200.24 scf/ton at the upside potential 1000 to 1500 meters is approximately 229.62 scf/ton. Based on the coal thickness, gas content, and the acreage area, Jorong-Kintap area is estimated to have good CBM development potential.