Five tugs with a combined force of more than 110,000 kilowatts have started the 500-nautical mile towout of the Aasta Hansteen platform from Stord.
The 12-day voyage to the Norwegian Sea is the biggest towout operation since the Troll A platform was moved offshore in 1996.
The Aasta Hansteen gas field is in 1,300 metres of water in the Vøring area, about 300 kilometres from land.
The field, which has recoverable reserves estimated at 51 billion standard cubic metres of gas, will be run from Harstad, by Statoil's Operations North organisation.
The supply base will be in Sandnessjøen and the helicopter base in Brønnøysund.
The gas field is being developed with a Spar FPSO platform, as the first on the Norwegian Continental Shelf and the largest in the world.
