ABSTRACT: Deepwater Exploration in an Eocene petroleum system, Salayar basin, Indonesia

Andreason, Mark W., Alan F. Chatfield, Joseph A. Curiale, Mark V. Filewicz, Eko D. Lumadyo, Timothy P. Seeley, and Sigit Sutiyono
Unocal Corporation, Sugar Land, TX

The Salayar Basin, located offshore southwest Sulawesi, is one of a series of rift basins formed during the Mid-Cretaceous along the southeastern Sunda shield margin. These rifts opened due to plate rollback as the Australian plate collided with the southeastern portion of the Sunda plate. Other basins, such as the Kutei, Tarakan, Barito, and East Java basins, which initiated at the same time as the Salayar basin are some the most hydrocarbon-rich basins in Indonesia. The Salayar basin has only been lightly explored in comparison to these other eastern Sunda margin basins, which share similar tectonic and thermal histories with the Salayar basin.

Paleocene - Middle Eocene fluvio-deltaic sandstones and Middle - Upper Eocene foraminiferal carbonate banks comprise the primary reservoir targets in the Salayar basin. Hydrocarbons are sourced from Paleocene - Eocene coals, oil-prone carbonates, and lacustrine mudstones. Previous exploration efforts have targeted large inversion structures, which formed during the Late Oligocene through Middle Miocene. Current understanding of the Paleocene-Eocene petroleum system points to hydrocarbon migration toward pre-inversion structures formed during the Cretaceous rift event.

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