Efficiency of Coal Mining Direction Based on Sedimentary Facies at PT Jambi Prima Coal, Sarolangun Regency, Jambi Province, Indonesia

Abstract Indonesia requires a large amount of conventional energy for its current development and economic growth (e.g., coal). The coal distribution in the Sumatra Island (e.g., Muara Enim Formation) has been influenced by the sedimentary facies, resulting in the spatial geometry of the coal seams (i.e., direction and thickness). Furthermore, my study focused to analyse the sedimentary facies and the geometry of the coal seams. Based on the measured stratigraphic and borehole data, the research resulted in 4 types of sedimentary facies and coal seam geometry. The existing facies were distributary channel, crevasse splay, interdistributary bay, and swamps, which were part of the transitional lower delta plain. In the swamp facies, there are two coal seams (i.e., magma and dipa seam). The thickness of the magma seam increased towards the southeast, while towards the southwest happened to rise the dipa seam thickness. However, the dipa seam was affected by a channel facies phenomenon, causing to split into the dipa upper and dipa lower. Therefore, for determining the mining efficiency based on the sedimentary facies, the southern part of the magma and the dipa seam can be considered as the mining area, with the mining direction from the southeast towards the northwest.