Publications

Southern portion of the West Java (SWJ) onshore area is a petroleum exploration frontier, with a lack of exploratory well data in the area, and no identified prospect of hidrocarbon to be worked up. Several petroleum systems may be present, hosted by sediments deposited in the transtensional Paleogene basin, Neogene and younger intra-arc basins. Three small sub basins might be present in the area with various sediments thickness, separated by border faults and are of significance for petroleum prospects. Field survey as the first exploration phase has been conducted between 1896 and 1932. Some post War activities were initiated during 1970s, they included a preliminary reconnaisance study and geophysical-gravity survey conducted by Pertamina and Lemigas. In early 1990s, geological activities were continued in order to increase existing knowledge on the source rock potential, stratigraphy and structures of the Tertiary succession, and to better define the petroleum systems. The more recent magnetic and seismic survey in 1990s remarked the current exploration cycle. In contrast to the stable northern petroleum basin, the southern mountain of West Java largely consists of an inverted sub-basins, containing strongly deformed sequences of Tertiary sediments and dissected arc remnants. The basal of Tertiary ranging from >2000 meters depth to the PreTertiary exposure at the Ciletuh area. Coal and shales of the Early Tertiary sediments were considered likely source rocks. Geochemical results from 200-400 m well samples of the Paleogene sediments indicate mature and oil/gas prone source rocks. The potential for significant petroleum accumulations appears greatest in the eastern part (Karangnunggal region and the adjacent structures). Subtle accumulation is possibly provided by the intricate structural, paleogeomorphic, and stratigraphic combination. On a regional scale, a thick “surficial volcanic, the retention for accumulation and an uncertainty of a viable kitchen are probably the most important factor limiting potential of hydrocarbon accumulations, although development of suitable reservoirs and structures elevating the potentials.Keyword: Southern Mts, West Java, Hydrocabon exploration