| Abstrak/Abstract |
Pematang Formation is the main source rock in the Central Sumatra Basin.The formation which acts as source rock has been studied thoroughly in the central andeastern parts of the basin, but research regarding source rock in the western part of thebasin, which is the study area, is very limited. This paper aims to define the quality ofsource rock from a geochemical view through the determination of organic content quan-tity based on the Total Organic Carbon (TOC) data, determining the type of kerogen, andthermal maturity of the source rock according to the values of Tmax and Vitrinite Re-flectance (%Ro). Burial history and thermal maturity models (1D basin modeling) werealso constructed to understand the timing of hydrocarbon generation. The results showthat Pematang Formation among Sihapas and Telisa Formation has good organic contentwith TOC ranging from 0.2 to 42.48 wt%, and the maturity parameters indicate that thePematang Formation has reached the mature stage. Both formations are dominated byType II kerogen. 1D modeling of the SHT-1 Well indicates that the Pematang Formation iscurrently in the oil maturity window, starting from early oil to main oil at 20.61 Ma, butthe model of the SMB-1 Well has not reached the oil maturity window. Tectonic activityis estimated to have had a significant effect on this difference when the uplift activity ofBukit Barisan in the Middle Miocene increased the maturity in the northwest. However,the inversion in the Late Miocene resulted in uplift and erosion of young sediments, thuslowering the temperature in some areas. |
