ABSTRACT: Northeast Betara Field, South Sumatera, Indonesia: stratigraphic architecture of a lower Talang Akar Reservoir

Suta, I. Nyoman, David Desautels, and Mark Gresko , Santa Fe Energy Resources Indonesia, Ltd, Jakarta, Indonesia

The Northeast Betara Field, located in South Sumatra, Indonesia, is a world class oil and gas field covering 34,000 acres. The Northeast Betara structure consists of a basement high with Tertiary burial that has been inverted due to compressive stresses during the Late Miocene-Pliocene. This has resulted in the formation of a horst bounded by reverse faults on the east and west and plunging to the south and north. The reservoir consists of Oligocene Lower Talang Akar fluvial channel sands deposited in meander belts. The sands are locally derived and onlap the old basement high and thicken down flank of the paleo-basement high. The reservoir interval is thin to absent at the crest, to several thousands of feet off structure. The gas column is six hundred feet high with a variable oil column ranging over 100 feet in thickness. The lateral and vertical amalgamation of the meander belts has resulted in complex reservoir geometry, with varying fluid contacts and lateral variation CO₂. A crestal well was originally drilled by Total Indonesia in 1971 and encountered thin sands with gas shows, but was not tested. In 1995, Santa Fe Energy Resources drilled the discovery downflank that resulted in over 100 feet of net gas pay. Subsequent wells delineated the oil rim. The field is now in the process of being developed along with two other nearby discoveries.

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