is a natural gas
and oil field
in the Norwegian
sector of the North Sea
, North-West of Bergen
, 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 west of Kollsnes
, near Bergen
, in water depths of . 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
(1.62%) and Total S.A.
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 tons
, the total height is . The depth is . 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.