ONE-DIMENSIONAL BASIN MODELING AND ORGANIC GEOCHEMISTRY STUDIES OF NGIMBANG SUBBASIN, NORTH EAST JAVA

• Main Author: Majeed Hartono, Barry
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/50127
• Institution: Institut Teknologi Bandung

The key of successful exploration is the understanding of the petroleum system by integrating geological, geochemical, and geophysical studies. The main important element of the petroleum system is the source rock. This study focuses on the understanding of the source rock in the East Java Basin. Source rock characterization (quantity, maturity, and quality of organic matter), geochemical correlation, and one-dimensional basin modeling was done in this study. Three hundred six rock geochemical data from 6 PT Pertamina EP wells are used in this study. The initial data then have been screened with total organic carbon (TOC) values resulting only 124 geochemical data. Five oil samples (one sample from Ngimbang Formation and four samples from Ngrayong Formation) were correlated with the source rock based on identical biomarker signature. This study shows that there are two oil families in the North East Java Basin, which are oil family that expelled from Ngimbang Source Rock and oil family that expelled from Lower Ngimbang Source Rock. The burial history curves and the sediment thickness in seismic section show that in the Middle Eocene to Early Oligocene, Ngimbang Formation is deposited as a syn-rift deposit. Later, Kujung Formation, Tuban Formation, Ngrayong Formation, and Wonocolo Formation are deposited as post-rift deposits. Major uplift in Tertiary-Quartenary boundary can be seen from burial history curves resulting the erosion of Ngrayong Formation and Wonocolo Formation. Based on basin modeling, Lower Ngimbang Source Rock matured in 32 Ma. This research also suggest that the Ngimbang Source Rock are deposited in fluvial environment different with previous idea that propose if Ngimbang Source Rock are deposited in lacustrine environment. The author hopes that this study can improve the understanding of the petroleum system and support the oil and gas exploration in East Java Basin.