Abstract

Belida Field is located in the South Natuna Sea, Block B PSC, offshore Indonesia and was discovered in 1989. The current Field estimated ultimate recovery (EUR) is approximately 350 MMBO. The field was developed in 1992 with one 20 well-slot, drilling and production platform. A 16 slot well-head platform and a lift gas compression platform were added in 1994. Peak oil production of 135,000 bopd was achieved in 1994 and current field production capacity is approximately 40,000 bopd. Drilling to date includes 8 exploration and appraisal wells and 40 oil production wells. Oil is produced from two sandstone reservoirs, the Early Miocene Lower Arang Formation and the Oligocene Udang Formation. Both reservoirs were deposited in a fluvial deltaic environment and are separated by the Barat Formation shales.

A 3D seismic survey acquired in 1991 guided field development. However, it is of poor to fair quality and has been used principally for structural interpretation. Throughout field life, reservoir simulation models have consistently underestimated individual well and field performance. History matching of the Udang production has been particularly problematic. Following the drilling of additional successful side-track wells in 2000 and 2001, and some unexpected results while drilling these wells, a decision was made to acquire new 3D seismic in 2001 and to undertake a complete technical re-evaluation of the field. This has included interpretation of the new seismic data and building new geologic and reservoir simulation models.

In addition, the 1991 seismic data has been reprocessed, providing a 4D seismic dataset. The aim of this paper is to present the technical re-evaluation of the Belida Field including an economic perspective to show how work of this nature, even at this late stage in field life, can add value to a mature asset and maximize ultimate hydrocarbon recovery.