ELECTROFACIES AND SEDIMENTARY STRUCTURE ANALYSIS FOR THE DETERMINATING COAL DEPOSITIONAL IN PIT J, SANGATTA COALFIELD USING GEOPHYSICAL WELL LOGS

ABSTRACT The identification of various deposition environments is indicated by all components of the deposition system and the location of the coal seams in the deposition environment based on the study of sedimentary environments, among others, supported by data from outcrop profiles (sedimentary structures), drilling, and geophysical logs. The research location in Upper Kutai Basin, which occupies the location of coal mining concession of PT Kaltim Prima Coal, precisely PIT J, with Balikpapan formation as a coal bearing formation. Some of coal observed are SE seam, NM seam and Sangatta seam. Electrolysis analysis results, this logging result is dominated by funneling and bell shape. This form is interpreted as a precipitation environment in the form of delta plain. The results of the lithological analysis (sedimentary structure) consisting of sandstone and rock / limestone constellations are characteristic of fluvial environmental up to upper delta plain. Based on research results, it can be interpreted depositional environment of coal in the area of research is the fluvio deltaic.