Development

Statfjord is a field in the Tampen area in the northern part of the North Sea, on the border between the Norwegian and UK sectors. The Norwegian share of the field is 85.47 per cent. The water depth is 150 metres. Statfjord was discovered in 1974, and the plan for development and operation (PDO) was approved in 1976. The field has been developed with three fully integrated concrete facilities: Statfjord A, Statfjord B and Statfjord C. Statfjord A, centrally located on the field, started production in 1979. Statfjord B, in the southern part of the field, in 1982, and Statfjord C, in the northern part, in 1985. The satellite fields Statfjord Øst, Statfjord Nord and Sygna have a dedicated inlet separator on Statfjord C. A PDO for Statfjord Late Life was approved in 2005.

Reservoir

Statfjord produces oil and associated gas from Jurassic sandstone in the Brent and Statfjord Groups, and in the Cook Formation. The Brent and Statfjord Groups have excellent reservoir quality. The reservoirs are at depths of 2500-3000 metres in a large fault block tilted towards the west, and in several smaller blocks along the eastern flank.

Recovery strategy

The field was originally produced by pressure support from water alternating gas injection (WAG), water injection and partially gas injection. Statfjord Late Life entails that all injection now has ceased. To release the solution gas from the remaining oil, depressurisation of the reservoirs started in 2007.

Transport

Stabilised oil is stored in storage cells at each facility. Oil is loaded onto tankers from one of the two oil-loading systems on the field. Since 2007, gas is exported through Tampen Link, and routed via the Far North Liquids and Gas System (FLAGS) pipeline to the UK. The UK licensees route their share of the gas through the FLAGS pipeline from Statfjord B to St Fergus in the UK.

Status

Work is ongoing to extend the lifetime of the field. Plans include prolonging the lifetime of the platforms and drilling of many new wells in the years to come. Satellite fields tied-back to Statfjord as well as nearby discoveries will benefit from the lifetime extension.