Gudrun Field, Norway

Gudrun oil and gas field lies in production licence 025 of the North Sea at a water depth of 361ft. The field was discovered in 1974 and is estimated to contain 70 million barrels of oil and 1.7 trillion cubic feet of gas.

StatoilHydro is the operator of the field with a 46.8% stake. Other partners include Marathon Norge with 28.2% interest and GDF SUEZ E&P Norge with a stake of 25%. The partners are investing $3.6bn in the development of the field.

The plan for development and operation (PDO) of the Gudrun field was sanctioned in June 2010. The PDO was submitted to the Norwegian Government in February 2010. First production is expected in the first quarter of 2014.

Gudrun platform

Statoil is planning to develop Gudrun using a fixed processing platform supported by a 7,400t steel jacket. The platform will be installed at a water depth of 357ft and will have 16 well slots. Statoil is initially planning to drill seven production wells. The remaining well slots of the platform may be used during future drilling activities to increase Gudrun's output.

The platform will be tied back to the existing facilities at Statoil-operated Sleipner field located 55km south of Gudrun.

It will also be connected to the Kårstø processing plant situated 30km north of Stavanger. The platform will receive power via a cable from the Sleipner field.

 The platform will be equipped with facilities to handle production from the Sigrun subsea satellite development.

Geology

The reservoirs of the Gudrun field are of the Jurassic era and lie at a depth of 4,000m-4,760m. Oil is deposited in reservoirs in the upper Jurassic Draupne formation. Gas is deposited in the middle Jurassic Hugin formation. Pressure of the reservoir is high at about 820bar.

Processing systems

The topsides of the platform will have a processing facility for partial processing of the oil and gas produced from the field. The oil and gas will then be sent to the Sleipner A platform and Kårstø processing plant where they will be further treated.

Oil will be stabilised at the Sleipner A platform and sent to the Kårstø processing plant. Water and salts will be removed from the oil at the Kårstø plant.

Gas produced at the field will be sent to the Sleipner T platform from Sleipner A. At Sleipner T, carbon dioxide will be removed from the gas. The gas is then sent back to Sleipner A from where it will be exported to Europe through the Gassled system.

Contracts

Aker Solutions was awarded a $77m contract in February 2010 for constructing the jacket for the platform. Delivery and installation of the platform is expected in mid-2011. Aker will carry out the engineering, fabrication and load-out of the jacket. The company will also be responsible for sea-fastening of the jacket.

Aker was awarded another contract worth $144m in July 2010 to carry out modifications to the existing facilities in the Sleipner area for tie-back of the Gudrun platform. The company will be responsible for engineering, procurement and installation of the equipment required for modification.

In June 2010, Statoil awarded Aibel a $430m contract to engineer and construct the topside facilities for the Gudrun platform. The platform deck will be constructed at Haugesund in Norway and is expected to be completed by July 2013.

Aibel was also awarded the front end engineering design (FEED) contract worth $9.3m in March 2009. The company carried out FEED studies for the topside facilities, living quarters and jacket interface.

Saipem was awarded a contract for transport and installation of the platform jacket and topside facilities in June 2010. The company will use its semi-submersible crane vessel S7000 to carry out the installation works.