The Foinaven field is located 118 miles (190 kilometers) west of the Shetland Islands in the UK on Blocks 204/19 and 204/24a. Situated in a water depth of 1,476 feet (450 meters), Foinaven was the first UK deepwater oil field to be developed in the Atlantic margin.

BP serves as the operator of the field and holds a 70% working interest; while Marathon holds the remaining interest.

Discovered in 1992, the Foinavan field is estimated to hold up to 1 billion barrels of oil. The field's reservoir is Paleocene in age and compromises channelized, siliciclastic turbidities with three main oil-containing sandstone intervals. In order to recover oil from the reservoir, hydrocarbon production volumes are replaced by injecting seawater into the reservoir via dedicated water injection wells.

Field Development

Sanctioned in October 1994, Foinaven's initial field development consisted of three wells tied-back to the Petrojarl Foinaven FPSO through a 4-mile-long (7-kilometer-long) production flowline.

The subsea layout consists of two drilling centers, which contain a manifold and a well cluster that are connected to a riser base by four rigid steel production/test flowlines. Eight flexible production risers, a water injection riser, a gas injection riser and two control umbilicals hang from the turret, which provides the connection from the FPSO to the subsea system.

The Petrojarl Foinaven FPSO, operated by Teekay Petrojarl, has an overall length of 787 feet (240 meters) and a displacement of 72,000 tons (65,317 tonnes). The vessel is a converted five-year submarine tender that underwent a major conversion by PGS Production at the Ferrol yard in Spain during 1995 and 1996. The modified FPSO has a storage capacity of 300,000 barrels and is turret-moored on the Foinaven field with production exported by two shuttle tankers.

The field commenced production in 1997 and four years later the vessel set a daily production record of 132,000 bopd. From the time the field commenced production, the partners continued to explore the area because additional opportunities were identified. By 2003, the field was fully developed by 32 subsea wells connected to four drilling centers. By adding to the field's subsea layout, Foinaven's initial reserves doubled from 200 million barrels oil equivalent to around 415 million barrels of oil equivalent.