Identification of Source Rock Characteristics Based on Total Organic Carbon (TOC) Sojomerto Area and Vicinity Gemuh District, Kendal Regency Central Java Province

The research area is in Sojomerto area and vicinity, Gemuh District, Kendal Regency, Central Java Province, about ± 107 km to the north of Yogyakarta City. The purpose of the study was to determine the characteristics of the source rock by identifying the characteristics of the source rock based on the total organic carbon (TOC) value at the research site based on TOC and REP value data using descriptive methods. Based on the results of the analysis, Total Organic Carbon (TOC) in LP 1 samples has a value of 0.50%, which means poor; LP 2 samples have a value of 0.56% is still classified as poor, and LP 3 samples show a smaller value of 0.27%, wich is still classified as poor. The results of TOC versus PY plotting in the analysed sample were 3 samples, predominantly occupying gas-prone and far below the oil-prone limit. The hydrogen index value shows that three samples (LP 1, LP 2, and LP 3) produce gas, and there are no samples that produce oil or oil and gas. The thermal maturity of the Kerek Formation, based on the HI versus Maximum Temperature chart, shows the immature and near-mature categoriest.