The Pre Collision Basin Configuration in Bintuni Area, Irian Jaya – An Alternative Idea of Hydrocarbon Potential in Pre Tertiary Sediment



The objective of conventional hydrocarbon exploration in Bird Head area Irian Jaya was focused on the carbonate Tertiary. It had been proven commercially in the Salawaty Basin, and marginally commercial in the Bintuni Basin such as Mogoi, Wasian, and Wiriagar fields. Gas discoveries in the Wiriagar Deep, Mogoi Deep, Vorwata, and Ubadari structures give a new insight to apply non-conventional method for hydrocarbon exploration potential in the Bintuni Basin.
The structural configuration of Bintuni Area is divided into NW-SE high and low complex, which consists of Sekak Ridge, Ayot Low, and Aimau-Mogoi High. Each of them is constructed by several . NW-SE plunging subs high and subs low. This configuration is the cumulative result of three major tectonic phases: Permo-Triassic pre rifting, Jurassic-Early Tertiary syn rifling, and Tertiary syn orogenic tectonic phases. The pre rifling and syn rifting tectonic phases were responsible to the forming of pre Tertiary basin, which occurred prior to collision between the Australian Plate and the Pacific Plate, whilst the syn orogenic tectonic phase rejuvenated the previous structures to control the development of the Tertiary basin.
The domino fault effect at the syn-rift tectonic phase formed NW-SE half graben and influenced the sediment depositional system, which sediment source generally from northeast. The Jurassic deltaic and Cretaceous-Early Tertiary turbidite were controlled by half graben configuration. The sediments, which deposited at the syn-rift phase and located at the down thrown of half-graben system will be the good reservoir potential, whilst the shale and coal which intercalating within the reservoir has good chance as the source rock due to sufficiency of burial process. The pre-rift reservoir has good porosity and permeability if located in the high position of the half-graben system.
Several models of sediment deposition at pre collision basin represent hydrocarbon potential in Pre Tertiary reservoir. These models probably are one of appropriate method to define play parameters for hunting oil and gas in Bintuni basin.


Authors : Elan Biantoro & Achmad Luthfi