Worldwide, carbonate buildups of all ages serve as reservoirs for more than 40 billion barrels of recoverable hydrocarbons. It is estimated that approximately 40% of this total occurs in Tertiary buildups in Southeast Asia. This wealth of hydrocarbon reserves makes these carbonate reservoirs, and particularly the Miocene buildups, an important petroleum reservoir in the the region. Carbonates in one form or another represent the best reservoir targets in the Aitape sub-basin. Reefal limestones have been mapped at outcrop along the northern and southern margins in the Aitape and are interpreted from seismic data to be present within the basin. Corraline fragments recovered in cores from the Puwani-1 well support the interpretation that the well was located on an eroded carbonate platform. Shallow water carbonates persist southward across the basin and reefs built on this carbonate platform extend upward into overlying deep-water sediments (Barida Beds) which provide source and seal potential for the reefal reservoirs. Large anticlines have also been mapped within the kitchen area of the basin and represent secondary targets in the basin.
The first recorded oil seeps in the Aitape sub-basin date back to 1910. Surface mapping between the 1920's and 1980's, as well as a small number of modern petroleum exploration wells drilled in the basin, have established that oil has been generated within the basin and that virtually all rocks within the basin are within the oil window below approximately 2500 metres or 2.0 seconds TWT. The first 60 years of exploration in the Aitape sub-basin developed exclusively around surface geological programs. Geophysical exploration began in the 1980's with aeromagnetic, gravity and seismic surveys. Nine shallow wells were drilled in the 1920's at Matapau, located on a series of surface seeps. To date, approximately only 400 km of 2D seismic has been acquired in the basin so it is under-explored. BHP Petroleum were the first to complete a modern exploration drilling campaign in the Aitape sub-basin with Puwani-1, Pulan-1 and Boap Creek-1. Puwani-1 established the deep-water foraminiferal Barida Beds have a fair to good source rock potential. These remain the only modern wells within the basin.