Alwyn on stream

These were installed in 1985 in 131 metres of water. NAA was equipped with drilling modules, living quarters and the control room, while NAB carried processing equipment and the pipeline terminal. Production drilling began in the autumn of 1986. Alwyn North was the third field to be tied back to Frigg when it came on stream a year later. Oil and condensate (light oil) were piped to Britain’s Cormorant Alpha platform and on to the Sullom Voe terminal in Shetland, while the gas flowed by pipeline via TP1 on Frigg to St Fergus in Scotland.

Conversion work on TP1 for receiving gas from Alwyn North began in 1985 and was completed in March 1987. The UK field began producing oil on 22 November 1987, and first gas reached TP1 in late December for onward transmission through the Frigg UK Pipeline to St Fergus.

Frigg production ceased for good on 26 October 2004, with gas no longer flowing through DP2, TP1, TCP2 and MCP-01. To maintain output from Alwyn North to St Fergus, the 24-inch pipeline to TP1 was modified in 2004 to bypass TP1 and tie directly into the 32-inch Frigg UK Pipeline on the seabed. At the same time, the British pipeline bypassed MCP-01 so that the shutdown of the latter could begin. The Frigg Norwegian Pipeline bypassed MCP-01 in 2005.