|This article needs additional citations for verification. (December 2009)|
|Start of production||1979|
|Estimated oil in place||90 million barrels (~1.2×107 t)|
|Estimated gas in place||600×109 cu ft (17×109 m3)|
The Cormorant oilfield is located 161 kilometres (100 mi) north east of Lerwick, Shetland, Scotland, in block number 211/26a. It was discovered in September 1972 at a depth of 150 metres (490 ft). Estimated recovery is 90 million barrels (14×106 m3) of oil. The oil reservoir is located at a depth of 2,895 metres (9,498 ft).
Production started in December 1979 from the Cormorant Alpha platform. This platform is a concrete gravity platform of the Condeep type. It has four legs and storage capacity for 1 million barrels (160,000 m3) of oil. The total sub-structure weight is 294,655 tonnes and it is designed to carry a topsides weight of 32,350 tonnes.
The topsides facilities included capability to drill, produce, meter and pump oil. It also has capability to re-inject water to maintain reservoir pressure. Peak production was 24,000 barrels per day (3,800 m3/d) in 1979. The platform is also the starting point for the Brent System pipeline, a major communications centre and the location of Brent Log - air traffic control for Northern North Sea helicopter traffic.
In addition an Underwater Manifold Centre (controlled from the Cormorant platform also produces oil. This started up in mid 1983. It has a design capacity for 50,000 barrels per day (7,900 m3/d). The UMC lost communications several years ago but a project ongoing in 2006 is looking to produce from the UMC once again. Also a single satellite well (P1) is linked to the platform with a design capacity of 10,000 barrels per day (1,600 m3/d).
A Norwegian organisation states that the Cormorant A platform almost sank in 1977 during its construction in Norway. This was disputed in a TV documentary on 7 May 2007.
On 16 January 2013 and again on 2 March 2013 a hydrocarbon leak in one of the legs of the platform was reported. Personnel was evacuated from the platform and the Brent System was closed down. No oil had been spilt into the sea. Many environmental groups called for the English and Scottish government to regulate the industry and the "aging" platforms more closely.
- "Abu Dhabi national energy company pjsc (taqa) agrees to purchase north sea assets from shell u.k. ltd and esso exploration and production u.k. ltd". Al Bawaba. 2008-07-07. Retrieved 2009-03-21.
- Lin Noueihed (2008-07-07). "Abu Dhabi's Taqa buys Shell, Exxon North Sea interests". Reuters. Retrieved 2010-02-09.
- "UK Brent oil system still shut after Cormorant leak". Reuters. 2013-03-03. Retrieved 2013-03-03.