The Statfjord satellites

person Harald Tønnesen and Finn Harald Sandberg, Norwegian Petroleum Museum
The Statfjord satellites is a collective term for three different reservoirs which have each been developed with their own solution, and tied back to the main field nearby. Statfjord North and East were developed as a single project, while Sygna forms part of the same licences as Statfjord East. The Statfjord north flank is regarded as part of the main licence. The satellites collectively increase reserves in the overall Statfjord area by about 15 per cent.
— Illustration of Statfjord C with adjacent satellites. Illustration: Statoil
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Statfjord East

Statfjord satelitter,
Illustration of Statfjord East. From the cover of Statfjord East Reservoir Development Plan produced by Statoil

This oil field lies about seven kilometres north-east of Statfjord, and was discovered in block 33/9 by the Norskald rig during 1976. Production licence 037 (the Statfjord licence) with Statoil as operator declared the field commercial in February 1988. A well drilled in block 34/7 by PL 089 with Saga Petroleum as operator established a connection with the structure in block 33/9. Saga declared this field commercial in June 1989. The field development plan was approved in 1900, and production began on 24 September 1994.

Reservoir and recovery strategy

The Statfjord East reservoir is built up from middle Jurassic sandstones. Its recoverable reserves are put at 231.4 million barrels of oil, 3.9 billion standard cubic metres (scm) of gas and 2.1 million tonnes of natural gas liquids (NGL). It produces through pressure support from water injection. An extended-reach production well was drilled from Statfjord C in 2006 to accelerate recovery.

Development solution

Located in 150-190 metres of water, the field has been developed with two four-slot subsea templates for oil production tied back to Statfjord C. In addition comes a four-slot template for water injection. The wellstream is carried in two pipelines to Statfjord C for processing, storage and onward transport, using the same platform facilities as Sygna and Statfjord North.

Statfjord North

This oil field lies 17 kilometres north of Statfjord. Proven in January 1977, it was declared commercial by operator Statoil together with Statfjord East in February 1988.

Reservoir and recovery strategy

Containing 247.8 million barrels of oil, 2.1 billion scm of gas and 1.1 million tonnes of NGL, Statfjord North’s reservoir comprises Jurassic sandstones. It is produced through pressure support from water injection.

Development solution

Preliminary evaluations in 1977-70 found that subsea installations would be an attractive production solution. Studies conducted up to 1987 concluded that any project would have to be viewed together with a Statfjord East development. The field has been developed with three subsea templates in 250-290 metres of water. Statfjord North D and E are for production, while Statfjord North F provides water injection. One well slot is used for a water injector on Sygna. Two 10-inch pipelines carry the wellstream to Statfjord C for processing, storage and onward transport, using the same platform facilities as Sygna and Statfjord East. All the Statfjord North installations are subsea and remotely controlled from Statfjord C.

Sygna

Produksjonsstart Sygna, forsidebilde, historie, Statfjord subsea, Tilknytningsavtaler, Statfjord satelitter
Sygna field plan. Illustration: Equinor

The Sygna oil field lies 22 kilometres north of Statfjord. Discovered in 1996, it was approved for development in 1999 and began production on 1 August 2000.

Reservoir and recovery strategy

Containing some 67.3 million barrels of oil, Sygna’s reservoir is built up from middle Jurassic sandstones. The field produces with the aid of water injection from Statfjord North, and is expected to remain on stream until 2014.

Development solution

Located in 300 metres of water, the field has been developed with the Sygna N subsea template. This installation provides four well slots and is tied back to Statfjord C. Three production wells have been drilled. Water injection capacity in the Statfjord North area was increased in 1999 to supply injection water for pressure support in Sygna, using a well from Statfjord North. The wellstream is carried in a pipeline to Statfjord C for processing, storage and onward transport, using the same platform facilities as Statfjord North and East.

Published July 9, 2018   •   Updated March 25, 2020
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