SOURCE ROCK CHARACTERIZATION AND CORRELATION WITH GEOCHEMICAL METHOD IN WEST MADURA OFFSHORE, NORTHEAST JAVA BASIN

• Main Author: Diah Anggraeni, Rhefika
• Format: Final Project
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/40504
• Institution: Institut Teknologi Bandung

The research area is located in Pertamina Hulu Energi West Madura Offshore block, JS-1 ridge area which is included in the North East Java Basin. Geographically, this research located at 112o40’ E to 113o05’ E and 6o20’ S to 6o45’ S. Geochemical analysis was carried out on eight source rock samples and four oil samples from twelve exploration wells, with the aim to determine the characteristics of source rock in form of quantity, quality, and maturity of organic matter and biomarker analysis to determine the depositional environment and correlation between oil and source rock. The results of the geochemical analysis show that the "OK" Formation has quantity in low-enough category, so the formation doesn’t have the potential to become source rock. Kujung Formation has quantity in low to very good category, type II – III kerogen, and immature, while the Ngimbang Formation quantity in low to good category, type II – III kerogen, and the maturity level is immature - mature. Thus, the formation that potentially becomes source rock in the research area is Ngimbang Formation. Based on biomarker analysis, the depositional environment of organic matter in Kujung Formation is interpreted from terrestrial with higher plants origin, while Ngimbang Formation from transition zone with the origin between algae and the dominance of higher plants. Correlation carried out using biomarker fingerprints show that oil samples are from one family. Meanwhile, the correlation between oil and source rock shows that oil is positively correlated with source rock of Ngimbang Formation.