ORGANIC PETROGRAPHIC AND GEOCHEMICAL CHARACTERISTICS OF KELESA FORMATION OIL SHALES, INDRAGIRI HULU REGENCY, RIAU PROVINCE

• Main Author: ANDHIKA YUDHA , MUHAMMAD
• Format: Final Project
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/29122
• Institution: Institut Teknologi Bandung

The research area is located in Indragiri Hulu Regency, Riau Province. Geographically, research area is located at coordinates of 102?0’6,6”-102?13’7,7” East Longitude and 0?47’14,8”-1?0’0” South Latitude. The research is focused on the oil shales of Kelesa Formation in the research area. The analysis is carried out on surface samples of Kelesa Formation to evaluate source rock, determine the type of oil shale, depositional environment, and the types of organic material. Geochemical analysis consists of Total Organic Carbon (TOC) and Rock-Eval pyrolisis. Organic petrographic analysis consists of organic material composition analysis, vitrinite reflectance analysis, and Thermal Alteration Index (TAI) analysis. Biomarker analysis consists of normal alkane, isoprenoid, steranes, and triterpanes data analysis from Gas Chromatography (GC) and Gas Chromatography Mass Spectrometry (GCMS). Based on the result, oil shales in the research area have quantity in very good to excellent category, quality as Type I up to III, with Type I being dominant, and immature to early mature stage of maturity. Lamalginite from Pediastrum is the main maceral in the samples, therefore the type of oil shales in the research area is Rundle-type lamosite. Liptinite maceral group has linear positive relationship with Potential Yield (PY) indicating that liptinite maceral group, particularly alginite plays a role in producing hydrocarbons in the research area. Based on the GC, GCMS, and maceral composition data, the depositional environment of Kelesa Formation oil shales in the research area is interpreted in lacustrine with balanced fill lake basin type.