Lithology Interpretation Based on Drilling and Geophysical Well Logging Data at Pit G Roto North PT Kideco Jaya Agung, Paser District, East Kalimantan Province.

Abstract

Coal is a non-renewable energy source and has a role that almost competes with petroleum. In this connection, it is necessary to explore and inventory coal resources. One of the exploration stages is drilling where data from drilling results can be used for coal resources and reserves estimation. PT Kideco Jaya Agung is one of the biggest coal mining companies in Indonesia, located in Paser District, East Kalimantan Province. In carrying out its drilling, PT Kideco uses the open hole, touch coring, and full coring drilling methods then compares it with the results of geophysical logging to obtain accurate coal thickness and depth data. Drilling data was obtained in the form of rock samples. The logging process is carried out after the drilling stage is complete. Logging methods used are gamma-ray logs, density logs, HRD logs, and BRD logs. Lithology interpretation is done by comparing rock sample data and log curves. The results of the interpretation of coal seams in drill hole ZA04 were found at a depth of 102.5 – 128.5 m with a true thickness of 10.78 m and in drill hole ZA05 coal was found at a depth of 106.2 – 121.7 m with a true thickness of 3.63 m.