- Installed 1975
- On stream 28 June 1978
- Shut down 1 January 2016
- Removal planned by 2022
Tor was discovered as early as 1970 by Amoco, drilling in neighbouring block 2/5. It was later found to extend into Ekofisk block 2/4, and licence interests were unitised on the basis of the estimated volume of hydrocarbons in each block (Phillips about 75 per cent and Amoco roughly 25 per cent).
Oil and gas were produced from two Tor-field formations – known as Tor and Ekofisk respectively. Tor 2/4 E had 15 producing wells. It stands in 70 metres of water. A separate flare stack was tied back to 2/4 E by a bridge. The platform’s highest point was 73 metres above sea level.
Output was separated in a three-phase production separator, with the oil stabilised before transport to Ekofisk 2/4 R in a 12-inch pipeline. Gas was dehydrated and sent to 2/4 R in a 14-inch pipeline. Both these pipelines were re-routed to Ekofisk 2/4 J in 1998.
The accommodation module originally provided 58 beds, but was replaced in 1982 with a new unit built at Stord Verft south of Bergen. Heerema/Seaway’s Balder crane barge did the lifting.
Capacity was thereby increased to 96 berths in double cabins over six stories. In addition, a module containing a laundry and workshop was lifted on board.
A new gas lift module was installed on Tor 2/4 E in 1989, making it possible to extend gas lift capacity from three to eight wells. This structure was fabricated in the USA and lifted into place by the DB 102 crane vessel.
Production ceased in January 2016, and plans call for the structure to be removed by 2022.