Troll is a

natural gas Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbon ...

and oil field in the

Norwegian Norwegian, Norwayan, or Norsk may refer to: *Something of, from, or related to Norway, a country in northwestern Europe * Norwegians, both a nation and an ethnic group native to Norway * Demographics of Norway *The Norwegian language, including ...

sector of the

North Sea The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian S ...

, one of the biggest in the North Sea, holding 40% of Norway’s gas – 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,Bolle, L., Troll Field, 1992, in ''Giant Oil and Gas Fields of the Decade, 1978-1988'', AAPG Memoir 54, Halbouty, M.T., editor, Tulsa: American Association of Petroleum Geologists, , pp. 447-458 about west of

Kollsnes Kollsnes is a natural gas processing plant operated by Equinor on the southern part of the island of Oøy in Øygarden Municipality in Vestland county, Norway. It processes the natural gas from the Troll, Kvitebjørn, and Visund gas fields. K ...

, near

Bergen Bergen (), historically Bjørgvin, is a city and municipality in Vestland county on the west coast of Norway. , its population is roughly 285,900. Bergen is the second-largest city in Norway. The municipality covers and is on the peninsula o ...

.Statoil
/ref> Most of the gas lies in Troll East.

Operators

The field is operated by

Equinor Equinor ASA (formerly Statoil and StatoilHydro) is a Norwegian state-owned multinational energy company headquartered in Stavanger. It is primarily a petroleum company, operating in 36 countries with additional investments in renewable energy. ...

, which has a 30.58% interest. The other partners are

Petoro Petoro is a company that is wholly owned by the Government of Norway. Established in 2001, it manages the Government's portfolio—collectively called State's Direct Financial Interest (SDFI)—of exploration and production licenses for ...

(56%),

Shell plc Shell plc is a British multinational oil and gas company headquartered in London, England. Shell is a public limited company with a primary listing on the London Stock Exchange (LSE) and secondary listings on Euronext Amsterdam and the New ...

(8.1%),

ConocoPhillips ConocoPhillips Company is an American multinational corporation engaged in hydrocarbon exploration and production. It is based in the Energy Corridor district of Houston, Texas. The company has operations in 15 countries and has production ...

(1.62%) and

TotalEnergies TotalEnergies SE is a French multinational integrated energy and petroleum company founded in 1924 and one of the seven supermajor oil companies. Its businesses cover the entire oil and gas chain, from crude oil and natural gas exploration and ...

(3.69%).

Platforms

Gas and oil from the field is extracted via three platforms – Troll A, B and C. The

Troll A platform The Troll A platform is a Condeep gravity-based structure offshore natural gas platform in the Troll gas field off the west coast of Norway. Built from reinforced concrete, , it was the tallest structure that has ever been moved to another posi ...

, based on the

Condeep Condeep is a make of gravity-based structure for oil platforms invented and patented by engineer Olav Mo in 1972, which were fabricated by Norwegian Contractors in Stavanger, Norway.Fagerberg; Mowery; Verspagen, p.192 ''Condeep'' is an abbrevi ...

technology, is the tallest structure ever to be moved. Total weight is 656,000

ton Ton is the name of any one of several units of measure. It has a long history and has acquired several meanings and uses. Mainly it describes units of weight. Confusion can arise because ''ton'' can mean * the long ton, which is 2,240 pounds ...

s and the total height is . The legs extend below sea level. This platform came into production in 1996 after being towed out from

Rogaland Rogaland () is a county in Western Norway, bordering the North Sea to the west and the counties of Vestland to the north, Vestfold og Telemark to the east and Agder to the east and southeast. In 2020, it had a population of 479,892. The admin ...

in May 1995 The Troll B Platform is a

semi-submersible Semi-submersible may refer to a self-propelled vessel, such as: *Heavy-lift ship, which partially submerge to allow their cargo (another ship) to float into place for transport *Narco-submarine, some of which remained partially on the surface *Se ...

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

Area

Extending across four North Sea blocks, the whole field covers just over 700

square kilometres Square kilometre ( International spelling as used by the International Bureau of Weights and Measures) or square kilometer (American spelling), symbol km2, is a multiple of the square metre, the SI unit of area or surface area. 1 km2 is equ ...

, corresponding to about 100 000 football pitches.

Geology

The reservoir is located in three eastward-tilted

fault block Fault blocks are very large blocks of rock, sometimes hundreds of kilometres in extent, created by tectonic and localized stresses in Earth's crust. Large areas of bedrock are broken up into blocks by faults. Blocks are characterized by rela ...

s 1500 m subsea and consists of cyclic shallow-marine

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates ...

s from the

Fensfjord Fensfjorden is a fjord in Vestland, Norway. The long fjord begins in the North Sea at Holmengrå Lighthouse and flows to the southeast through the municipalities of Austrheim, Gulen, Lindås, and Masfjorden. The fjord ends on the Masfjorde ...

, middle Heather,

Sognefjord The Sognefjord or Sognefjorden (, en, Sogn Fjord), nicknamed the King of the Fjords ( no, Fjordenes konge), is the largest and deepest fjord in Norway. Located in Vestland county in Western Norway, it stretches inland from the ocean to the sm ...

and upper Heather

formation Formation may refer to: Linguistics * Back-formation, the process of creating a new lexeme by removing or affixes * Word formation, the creation of a new word by adding affixes Mathematics and science * Cave formation or speleothem, a secondary ...

s in the

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

Viking Group, and are overlain by Upper Jurassic to

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pal ...

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay part ...

s. Located in the eastern margin of the Viking

Graben In geology, a graben () is a depressed block of the crust of a planet or moon, bordered by parallel normal faults. Etymology ''Graben'' is a loan word from German, meaning 'ditch' or 'trench'. The word was first used in the geologic contex ...

, water depths range from 300–355 m.

References

External links

Troll in the Interactive Energy Map of AftenbladetArticles on Troll at Equinor 50 years history page
{{Resources in Norway Oil fields in Norway Natural gas fields in Norway North Sea energy Equinor oil and gas fields Shell plc oil and gas fields ConocoPhillips oil and gas fields TotalEnergies