Source rock characterization based on geochemical observations using Well BO-1, Central Sumatra Basin

Abstract

The Central Sumatra Basin, characterized as a tertiary back-arc basin, stands as one of Indonesia’s foremost hydrocarbon-producing basins. Consequently, in the pursuit of hydrocarbon exploration endeavors, a comprehensive analysis of the potential source rocks within this region becomes imperative. The focal point of this study is the BO-1 well, situated within the Pematang Formation. Geochemical analysis methods, specifically leveraging Total Organic Carbon (TOC) and Rock-Eval Pyrolysis data, were employed to assess the quality, quantity, and maturity of the source rock. The research findings reveal a noteworthy organic material content at a fair-to-good level, registering an average TOC value of 0.69% and a Potential Yield of 1,994 mg/g, both falling within the fair-to-good classification. The Hydrogen Index value designates the source rock as type III kerogen, indicating a propensity for gaseous product generation. Maturity evaluation places the source rock within an immature to mature range, with a maximum temperature range of 383-452°C. In summary, the analysis discerns the source rock within the research area as an effective type, characterized by a substantial organic material abundance at a fair-to-good level and a mature maturity level. This conclusion is reinforced by the lithology of the research area, predominantly comprising mudstone, recognized for its richness in organic material.