Petroleum Geological Characteristics and Exploration Potential Analyses of West Natuna Basin, Indonesia

The West Natuna Basin, an intracratonic rifted basin in northern Sunda Shelf, is an important petroliferous basin in Indonesia. It has experienced four stages of evolution: syn-rifting, post-rifting, compression and... [ view full abstract ]

The West Natuna Basin, an intracratonic rifted basin in northern Sunda Shelf, is an important petroliferous basin in Indonesia. It has experienced four stages of evolution: syn-rifting, post-rifting, compression and syn-inversion, tectonic quiescence. The basin was filled with about 4.5 km thick sediments, which are overwhelmingly dominated by the Cenozoic. Two sets of source rocks were developed in the Upper Eocene-Lower Miocene succession, of which Belut Formation lacustrinal mudstones are the principal source rock. Hydrocarbon is mainly reserved in the Upper Oligocene - Lower Miocene Gabus Formation and Arang Formation. Regionally, Oil and gas is mostly distributed in the anticline structure belts of the Bawal Graben and the Penyu Sub-basin. By the end of 2012, 714 MMbbl of liquids and 3864 Bcf of gas had been in the basin. Integrated petroleum geological analyses indicate that the basin has a considerable hydrocarbon prospectivity. The draping structural traps, subtle traps related to unconformity and facies change, which are around the permeter or in the deep formation of the basin with low to moderate exploration level, will be the important area and targets for future exploration.