Awang H. Satyana*
* SKK Migas
Occupying the position of the active southern margin of the Eurasian Plate since the Cretaceous, Java Island has thick volcanic covers from Paleogene to Recent times. Numerous oil and gas seeps occur on Java Island where Paleogene to Recent volcaniclastic sediments are at the surface concealing prospective basin sediments. Before good geologic science was applied, people believed that oil was derived from magmatism and volcanism (inorganic theory). Now we understand that the hydrocarbons were organically derived from maturation of organic matters within source rocks in sedimentary basins. The volcaniclastic sediments buried the source rocks, burying the source rocks to depths of oil and gas windows. Oil and gas seeps in volcanic areas of Java show the presence of active petroleum systems underneath the volcanic cover. This indicates hydrocarbon prospectivity on Java Island (subvolcanic play) that is so far unexplored. The areas that show this prospectivity are: Banten Block, Majalengka Banyumas Area, and North Serayu Area. However, volcaniclastic covers are notorious for causing poor seismic data quality, making subsurface imaging difficult. This will challenge the methods and techniques of seismic and nonseismic data acquisition and processing. Once these challenges are resolved, the subvolcanic play of Java may be revealed.
Proceedings, Indonesian Petroleum Association, Thirty-Ninth Annual Convention and Exhibition, May 2015, IPA15-G-105.
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