Publications

The North Serayu Basin located in northern Central Java with a proven active petroleum system. The evidence is numerous hydrocarbon seepages on the surface within the basin, such as Bawang, Klantung, and Cipluk. The North Serayu Basin has hydrocarbon potential but remain under explored due to the volcaniclastic overburden, which are well known to cause poor seismic data. The basin has some reservoirs that have hydrocarbon occurances. One of them is the Late Miocene Cipluk Sandstone and the Parigi Carbonate equivalent. The focus of this study is reservoir characterization of Cipluk sandstone and Parigi carbonate eq., source rock type, trap type and migration direction. The study was perfomed using available literatures and subsurface data. Based on geochemistry analysis, it can be inferred that the best source rock in the basin is the Talang Akar Formation equivalent, with Kerogen type II and III and is dominated by oil and gas prone materials. Source rock is mature due to basin depression and Late Miocene sediment suppression. The Late Miocene reservoir in this area is a productive reservoir. The reservoir is known as Cipluk Sandstone in the south and Parigi Carbonate eq. in the north. Subsurface data shows a unique case of hydrocarbon distribution. The difference of hydrocarbon type might be controlled by the trap type and migration direction. Structural trap dominantly developed in the south with volcanic influences. In the north, stratigraphic traps developed dominantly without any volcanic influences. The conclusions are that the north area is gas prone which is associated with carbonate reservoir and biogenic gas, and that the south area is oil prone which is associated with sand reservoir and thermogenic oil. This study has been successfully performed to define the play concept in the basin.