Publications

Petroleum exploration before 1990s on the North of the Arafura Shelf was fairly limited. Previous operators drilled six wildcat wells on the northern part of the shelf: the Kembelangan-1 onshore well was drilled by the Dutch in 1956, while the ASA-1x, ASB-1x, ASE-1x, ASF-1x and ASM-1x wells were drilled by Phillips offshore in 1970-1974. All of these wildcats were P & A and no significant hydrocarbon was found. The proven regional reservoirs are the prolific Miocene reef carbonates of the Kais formation in Salawati basin, the Cretaceous Woniwogi in the Central Range (equivalent to the Toro sandstones in Papua New Guinea) and the Jurassic Roabiba sandstones in the Bintuni basin. The Birds Head region is the primary focus of exploration activity in eastern Indonesia, mainly resulting from the giant gas discoveries in the Mesozoic of the Bintuni Basin. Since then, most hydrocarbon exploration on the Arafura shelf and surrounding areas has targeted clastics reservoirs from Mesozoic formations and generally disregarded the tertiary formations. In 1997, KNOC acquired a block covering the NW margin of the Arafura Shelf and, based on intensive geoscientific studies through the period, Mesozoic and Cenozoic formations have been identified as worthy of an operators keen interest, in terms of both potential reservoirs and source rock for future exploration targets in the area. Further study of the area led the operator to focus its interest on testing the Tertiary petroleum system in the northern portion of the block. Following recent tests, the Middle Miocene Carbonate known as Upper Yawee Formation has been demonstrated as a potentially good reservoir to receive a hydrocarbon charge in this area. A working petroleum system, involving tertiary sediments, is very attractive for new hydrocarbon exploration. This particularly applies to frontier areas of Eastern Indonesia, such as the North Arafura shelf.