ABSTRACT: An overview: geological and economic prospect in Timoforo Block, Irian Jaya

Idris, Raden¹ and Redesmon Munir²
(1) PERTAMINA, Jakarta, Indonesia 
(2) PERTAMINA, N/A

The Timoforo Block lies in the Bird's Head region of Irian Jaya. This area is located northern of Wiriagar Block (ARCO) and Muturi Block (British Gas). The Timoforo Block is Pertamina acreage, while Timoforo anticline covers Pertamina and open acreage. The Timoforo Block is the northern edge of Bintuni Basin which is not much affected by tectonic.

In the surrounding areas of Timoforo Block, sandstone of Ainim Formation in Mogoi Deep #1 and limestone Kais Formation in Mogoi and Wasian oil field are proven as the reservoir rock potential content of hydrocarbon. Whereas, the Permian Ainim has excellent source rock potential (coal, shale) with TOC range 1.51 - 88.01 %, HI range 105-274. Modeling analysis of Bintuni Basin shows that hydrocarbon generation has occurred at Early Jurassic and expulsion at Middle Eocene.

The evaluation result using limited geologic data and seismic section shows that in the southern of Timoforo Block could be detected at least three structure having total of reserves around 1.7 TCF. In addition there are it still probably other structures in the area. However, according to economic evaluation, we have obtained this area is attractive enough for exploration. We use the parameters as follows : discount rate 15 %, gas price 1.8 USD/MCF and cost production 0.7 USD/MCF. So, we have NPV + 74 million USD, IRR 28.20 %, PI 1.51, POT 7.38 years and 13 years production life.

AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia