Geological Condition Characterization and Coal Resource Estimation at the “KJG” Pit of PT Bukit Asam Tbk, Muara Enim Regency, South Sumatra Province

Abstract Coal is a conventional energy source found in tropical countries (e.g., Indonesia) with varying distribution and thickness in the South Sumatra Basin. However, the thickness of the coal seams was not evenly distributed. This affected the estimation of coal resources in the mining area of PT Bukit Asam Tbk in Tanjung Enim, Muara Enim Regency. We used field observation methods and borehole data analysis to determine the geological conditions and estimate the coal resources. The geological condition seems to indicate a claystone unit with tuffaceous sandstone interbeds and a sandstone unit with claystone interbeds. These two units might host coal seams (i.e., A1, A2, B1, B2, and C), where the coal seam thickness may determine increased towards the south and west in the study area. The coal resource estimation based on the SNI 5015: 2019 classification, under moderate geological conditions, can result in a total of 26.034.991 tonnes of measured resources, 25.209.688 tonnes of indicated resources, and 11.189.554 tonnes of inferred resources. Therefore, to ensure efficient coal mining in accordance with the measured reserves, the stripmining method may be used by the company.