Valhall oil field
Encyclopedia
Valhall is an oil field in the Norwegian
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...

 sector of the North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...

. Discovered in 1975, production began in 1982 and is expected to continue until 2050. Valhall is located in 70 metres of water.

Development

The field was originally developed with three facilities (QP, DP and PCP) but now the complex consists of five separate steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...

 platforms
Oil platform
An oil platform, also referred to as an offshore platform or, somewhat incorrectly, oil rig, is a lаrge structure with facilities to drill wells, to extract and process oil and natural gas, and to temporarily store product until it can be brought to shore for refining and marketing...

 that are bridge-connected. There are also two unmanned flank platforms, one in the south and one in the north, both around 6 kilometres from the field centre.

Quarters Platform (QP)

The QP was built in 1979 and started being used in July 1981. It has accommodation for 208 people.

Drilling Platform (DP)

The DP is situated centrally and has 30 well slots. The platform started operation on 17 December, 1981 with the first covered derrick
Derrick
A derrick is a lifting device composed of one tower, or guyed mast such as a pole which is hinged freely at the bottom. It is controlled by lines powered by some means such as man-hauling or motors, so that the pole can move in all four directions. A line runs up it and over its top with a hook on...

.

Production Platform (PCP)

The PCP is built to process 168000 barrels (26,709.9 m³) of oil
Petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...

 and 350 Mcuft of gas
Natural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...

 per day. The platform is 65 metres high and weighs 21,000 tons. The oil production is piped to 2/4-J at the Ekofisk Center
Ekofisk oil field
Ekofisk is an oil field in the Norwegian sector of the North Sea about southwest of Stavanger. Discovered in 1969, it remains one of the most important oil fields in the North Sea. Production began in 1971 after the construction of a series of off-shore platforms by Phillips Petroleum Company...

 and goes to Teesside
Teesside
Teesside is the name given to the conurbation in the north east of England made up of the towns of Middlesbrough, Stockton-on-Tees, Redcar, Billingham and surrounding settlements near the River Tees. It was also the name of a local government district between 1968 and 1974—the County Borough of...

 in England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

. The gas is transported directly via the Norpipe pipeline
Norpipe
Norpipe is the undersea oil and natural gas pipeline's system in the North Sea. It supplies oil from the Norwegian Ekofisk and associated fields in the North Sea to the United Kingdom and natural gas to Germany.-Oil pipeline:...

 to Emden
Emden
Emden is a city and seaport in the northwest of Germany, on the river Ems. It is the main city of the region of East Frisia; in 2006, the city had a total population of 51,692.-History:...

 in Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

. The platform also processes oil and gas that comes from the Hod oil field.

Wellhead Platform (WP)

The WP was installed in April 1996 and first oil production started in June the same year. WP has 19 well slots. A central location and spare available capacity make it possible for the Valhall complex to also receive oil and gas from several adjacent fields.

Water Injection Platform (WIP)

The WIP is a fixed steel platform
Fixed Platform
A fixed platform is a type of offshore platform used for the production of oil or gas. These platforms are built on concrete and/or steel legs anchored directly onto the seabed, supporting a deck with space for drilling rigs, production facilities and crew quarters. Such platforms are, by virtue of...

, bridge linked to the existing Valhall WP. Water injection is expected to increase oil recovery from 31% to 38%. The integrated topsides has water injection facilities, seawater and produced water treatment facilities and power generation. The platform-based drilling rig's configuration allows for drilling and maintenance of wells on the new platform (24 wells total) and on the existing WP platform (19 wells total). The IP has integrated connections to the onshore operating centre.

Valhall Flank Development (VFD)

The VFD consists of two identical unmanned wellhead
Wellhead
A wellhead is a general term used to describe the component at the surface of an oil or gas well that provides the structural and pressure-containing interface for the drilling and production equipment....

 platforms each equipped with 16 drilling slots and located about 6 km (one to the North and one to the South) from the existing Valhall Facilities where wellstreams will be processed.

Initially about eight wells will be drilled from each platform. There is room for future water injection at either wellhead platform. The two wellhead platforms are powered from Valhall and monitored from the existing Valhall facilities via a fiber optic cable
Cable
A cable is two or more wires running side by side and bonded, twisted or braided together to form a single assembly. In mechanics cables, otherwise known as wire ropes, are used for lifting, hauling and towing or conveying force through tension. In electrical engineering cables are used to carry...

.

Drilling commenced on the South Flank by West Epsilon in October 2002 and continued until August 2003 when it moved to drill the North Flank. The South Flank started production 8 May 2003. While the North Flank came on stream 7 January 2004.

New field centre

Due to subsidence of the field centre and a desire to operate more efficiently a new field centre is being developed for Valhall. The new field centre will probably extend the life of the field to 2050.

Production & Hotel (PH) Facility

The PH facility will consist of an integrated processing and housing platform, and is due for installation in 2010. The topsides will weigh 16,000 tonnes (including hotel) and have accommodation for 150 people. The steel jacket will weigh 7,500 tonnes. This new platform will also have a module for receiving electrical power from shore.

External links

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