ABSTRACT: Pre-development characterisation of a marginal, deep-marine channel/lobe system reservoir - Block 9, Bredasdorp basin, Offshore Republic of South Africa

The SABLE field was discovered in 1990 at a depth of 2605 metres approximately 95 kilometres off the southern coast of South Africa. The discovery borehole, E-BD1, flowed 8 500 barrels of oil per day. The field consists of two overlapping reservoirs, the upper oil-bearing E-BD reservoir and the lower E-CE oil- and gas-bearing reservoir with a vertical separation of approximately 30 metres between them.

In order to refine in-place volumes of oil prior to a field development decision, modelling of the reservoir was done using an integrated software package for three dimensional object-based modelling and visualisation of reservoirs. The main challenge was to model the reservoir distribution and internal characteristics over the entire field whilst still honouring borehole data in each case, including boundary dimensions derived from welltest data.

A development plan calling for five initial producers (two of them horizontal), a water injector and a gas injector is under construction. The plan outlines how the E-BD reservoir pressure will be maintained by water-injection whilst gas produced from the E-BD reservoir will be re-injected into the lower E-CE gas cap to improve recovery from the underlying oil-leg.

The development of the field will use a unique floating production and storage system similar to that used on the presently producing ORIBI and ORYX fields which lie 18 kilometres to the south-east. The SABLE field is expected to be in production by the end of 2001 with an initial field flow rate of 40 000 barrels of oil per day. SABLE is operated by SOEKOR EandP, with partners Pioneer Natural Resources Ltd., Petroleum Ltd., and Energy Africa.

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