Publications

Kendeng has been well-known as the main depocenter in East Java Basin with the complexity of hydrocarbon discoveries. This paper aims to evaluate petroleum elements in Kendeng onshore, integrating regional and surface transects in order to better understand how the system works and contribute towards future hydrocarbon exploration in this area. Integrated study was conducted, including surface geological mapping, outcrop sampling, and laboratory analysis. Pelang Shale of the Djuwangi area shows poor to good organic richness. However, it is interpreted as being immature with low ability of generating hydrocarbon from mixed kerogen type II and III. Possible reservoir rock includes Miocene Kerek Sandstone with primary porosity ranging from 2-10% from maximum 6 m of thickness. Calcite cementation and longer period of burial has been interpreted to affect the quality of the sandstone. Oil seeps found in the Kedungjati, Djuwangi and Kedungwaru areas are indication of working petroleum system, related to trapping failure that cause the hydrocarbon migrated and charged the existing prolific fields in the Randublatung area. Proven petroleum system in Kendeng has been well developed particularly in the Southern Madura Sub-Basin with marginal hydrocarbon reserves. Recommendation for future exploration in Kendeng will be towards the edge of Ngawi and South Madura Sub-Basin (Eastern Kendeng) with Kujung Reef and globigerina sand as the main reservoir target. Further study in the North of Bogomiring Field and West of Petiken-1 can help to identify hydrocarbon prospects especially when incorporate both surface and subsurface data. Keywords: Kendeng, Petroleum System, Regional, Seepage.