GEOCHEMISTRY STUDY AND SOURCE ROCK MATURITY MODELING OF TALANGAKAR FORMATION ON TUNGKAL BLOCK, SOUTH SUMATERA BASIN

• Main Author: SIGIT WIBOWO (NIM: 22013318), SUSANTO
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/31156
• Institution: Institut Teknologi Bandung

<p align="justify">Talangakar Formation sediment, which is believed to be one of the major source rocks in South Sumatera Basin. Ditch cutting and oil samples were analyzed using geochemistry analysis and followed maturity modeling. The total organic carbon contents of the sediment range from 0.4–80% TOC and there are two types of <br /> <br /> source rocks which are shale and coals. All sediment samples analyzed have vitrinite reflectance in the range of 0.2-0.65% Ro and Tmax value between 400-4500 C, which indicate that Talangakar sediments contain immature to late <br /> <br /> mature organic matter. The sediments are dominated by mixed type II/III and type III kerogen. Typical oil and gas generating potential is anticipated from the sediments with fairly high hydrogen indices (HI) from 50-400 mgHC/gTOC. <br /> <br /> One dimensional basin modeling was performed to analyze the hydrocarbon generation potential and expulsion history of Late Oligocene Talangakar sediments in the South Sumatera Basin based on the reconstruction of the burial <br /> <br /> and thermal maturity histories. This is to improve understanding of the hydrocarbon generation potential of the source rocks. Calibration of the model with measured vitrinite reflectance (Ro) and borehole temperature data reveals that the present-day heat flow in the Tungkal Block located northern part of the South Sumatera Basin varies from 93-107 mW/m2. The source rock of the Talangakar Formation at well location is presently at a stage of early to main oil generation, no gas generation with thermal maturity ranging from 0.5-1.3% Ro. <br /> <br /> The modeled burial history suggests that maximum burial occurred in the Pliocene, uplifting and erosion might the cause of the anomaly high value vitrinite reflectance at the shallower depth.<p align="justify">