Troll is a natural gas and oil field in the Norwegian sector of the North Sea, one of the biggest in the North Sea, holding 40% of Norway’s gas[1] – it also possesses significant quantities of oil, in thin zones under the gas cap, to the west of the field.

The Troll C Platform is a conventional steel hull semi-submersible designed by GVA Consultants.

Extending across four North Sea blocks, the whole field covers just over 700 square kilometres, corresponding to about 100,000 football pitches.

[7] The reservoir is located in three eastward-tilted fault blocks 1,500 m subsea and consists of cyclic shallow-marine sandstones from the Fensfjord, middle Heather, Sognefjord and upper Heather formations in the Jurassic Viking Group, and is overlain by Upper Jurassic to Paleocene clays.

[2] Located in the eastern margin of the Viking Graben, water depths range from 300–355 m.[2]