Troll oil field
Encyclopedia
Troll is a natural gas
and oil field
in the Norwegian
sector of the North Sea
, 100 kilometres (62.1 mi) North-West of Bergen
, 50 kilometres (31.1 mi) west of the island of Fedje.
Although Troll is primarily a gas field – one of the biggest in the North Sea, holding 60% of Norway’s gas reserves – it also possesses significant quantities of oil, in thin zones under the gas cap, to the west of the field. The field as a whole consists of the main Troll East and Troll West structures in blocks 31/2, 31/3, 31/5 and 31/6, about 65 kilometres (40.4 mi) west of Kollsnes
, near Bergen
, in water depths of 315 to 345 m (1,033.5 to 1,131.9 ft). Most of the gas lies in Troll East.
The field is operated by Statoil
, which has a 30.58% interest. The other partners are Petoro
(56%), Royal Dutch Shell
(8.1%), ConocoPhillips
(1.62%) and Total S.A.
(3.69%).
Gas and oil from the field is extracted via three platforms – Troll A, B and C.
The Troll A platform
, based on the Condeep
technology, is the largest structure ever to be moved. Total weight is 656,000 ton
s, the total height is 472 metres (1,548.6 ft). The depth is 303 metres (994.1 ft). This platform came into production in 1996.
The Troll B Platform is a semi-submersible
designed by Doris
and fabricated from concrete; thought to be the only concrete semisubmersible. This platform came into production in 1995.
The Troll C Platform is a conventional steel hull semi-submersible
designed by GVA Consultants
. This platform came into production in 1999.
Natural gas field
Oil and natural gas are produced by the same geological process according fossil fuel suggestion: anaerobic decay of organic matter deep under the Earth's surface. As a consequence, oil and natural gas are often found together...
and oil field
Oil field
An oil field is a region with an abundance of oil wells extracting petroleum from below ground. Because the oil reservoirs typically extend over a large area, possibly several hundred kilometres across, full exploitation entails multiple wells scattered across the area...
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...
, 100 kilometres (62.1 mi) North-West of Bergen
Bergen
Bergen is the second largest city in Norway with a population of as of , . Bergen is the administrative centre of Hordaland county. Greater Bergen or Bergen Metropolitan Area as defined by Statistics Norway, has a population of as of , ....
, 50 kilometres (31.1 mi) west of the island of Fedje.
Although Troll is primarily a gas field – one of the biggest in the North Sea, holding 60% of Norway’s gas reserves – it also possesses significant quantities of oil, in thin zones under the gas cap, to the west of the field. The field as a whole consists of the main Troll East and Troll West structures in blocks 31/2, 31/3, 31/5 and 31/6, about 65 kilometres (40.4 mi) west of Kollsnes
Kollsnes
Kollsnes is a natural gas processing plant owned and operated by Statoil on the southern part of the island Oøy in Øygarden, Norway. It processes the natural gas from the gass fields Troll, Kvitebjørn and Visund with a capacity of 143 million standard cubic meters of natural gas per...
, near Bergen
Bergen
Bergen is the second largest city in Norway with a population of as of , . Bergen is the administrative centre of Hordaland county. Greater Bergen or Bergen Metropolitan Area as defined by Statistics Norway, has a population of as of , ....
, in water depths of 315 to 345 m (1,033.5 to 1,131.9 ft). Most of the gas lies in Troll East.
The field is operated by Statoil
Statoil
Statoil ASA is a Norwegian petroleum company established in 1972. It merged with Norsk Hydro in 2007 and was known as StatoilHydro until 2009, when the name was changed back to Statoil ASA. The brand Statoil was retained as a chain of fuel stations owned by StatoilHydro...
, which has a 30.58% interest. The other partners are Petoro
Petoro
Petoro, a company wholly owned by the state of Norway, manages Norway's portfolio of exploration and production licenses for petroleum and natural gas on the Norwegian continental shelf. This portfolio is collectively called State's Direct Financial Interest . The company also has a control...
(56%), Royal Dutch Shell
Royal Dutch Shell
Royal Dutch Shell plc , commonly known as Shell, is a global oil and gas company headquartered in The Hague, Netherlands and with its registered office in London, United Kingdom. It is the fifth-largest company in the world according to a composite measure by Forbes magazine and one of the six...
(8.1%), ConocoPhillips
ConocoPhillips
ConocoPhillips Company is an American multinational energy corporation with its headquarters located in the Energy Corridor district of Houston, Texas in the United States...
(1.62%) and Total S.A.
Total S.A.
Total S.A. is a French multinational oil company and one of the six "Supermajor" oil companies in the world.Its businesses cover the entire oil and gas chain, from crude oil and natural gas exploration and production to power generation, transportation, refining, petroleum product marketing, and...
(3.69%).
Gas and oil from the field is extracted via three platforms – Troll A, B and C.
The Troll A platform
Troll A platform
The Troll A platform is a condeep offshore natural gas platform in the Troll gas field off the west coast of Norway. It is the tallest construction that has ever been moved to another position, relative to the surface of the Earth, and is among the largest and most complex engineering projects in...
, based on the Condeep
Condeep
Condeep refers to a make of gravity base structure for oil platforms developed and fabricated by Norwegian Contractors in Stavanger, Norway. A Condeep usually consists of a base of concrete oil storage tanks from which one, three or four concrete shafts rise...
technology, is the largest structure ever to be moved. Total weight is 656,000 ton
Ton
The ton is a unit of measure. It has a long history and has acquired a number of meanings and uses over the years. It is used principally as a unit of weight, and as a unit of volume. It can also be used as a measure of energy, for truck classification, or as a colloquial term.It is derived from...
s, the total height is 472 metres (1,548.6 ft). The depth is 303 metres (994.1 ft). This platform came into production in 1996.
The Troll B Platform is a semi-submersible
Semi-submersible
A semi-submersible is a specialised marine vessel with good stability and seakeeping characteristics. The semi-submersible vessel design is commonly used in a number of specific offshore roles such as for offshore drilling rigs, safety vessels, oil production platforms and heavy lift cranes.The...
designed by Doris
Doris
- Geography :* Doris , region of Asia Minor inhabited by Dorians* Doris , region in central Greece in which the Dorians had their traditional homeland* Doris, Iowa, USA- People :* Doris, mother of Antipater...
and fabricated from concrete; thought to be the only concrete semisubmersible. This platform came into production in 1995.
The Troll C Platform is a conventional steel hull semi-submersible
Semi-submersible
A semi-submersible is a specialised marine vessel with good stability and seakeeping characteristics. The semi-submersible vessel design is commonly used in a number of specific offshore roles such as for offshore drilling rigs, safety vessels, oil production platforms and heavy lift cranes.The...
designed by GVA Consultants
GVA Consultants
GVA Consultants is a Swedish marine and offshore engineering company specialising in the design of offshore structures, and semi-submersible platforms.-History:The experience of GVA as a marine engineering company stretches back more than 25 years...
. This platform came into production in 1999.