Pipelaying season starts
Work is starting on the Gullfaks gas export line, the first of four pipelaying projects being pursued by Statoil this spring and summer.
The Lorelay laybarge arrived on the North Sea field on 26 April and will start laying from Gullfaks A as soon as weather conditions permit.
This 35-kilometre line will run west to tie into Statoil's Statpipe gas trunkline using a hot-tap operation – performed without interrupting the gas flow – before looping back to Gullfaks C.
Only one hot tap has been done off Norway before, again by Statoil. The group did this job in 1998 to tie a gas line from Esso's Jotun development to Statpipe.
The project involves several demanding subsea operations, which include making flange connections for pipeline sections without diver assistance in more than 180 metres of water.
"This approach saves many millions of kroner by avoiding subsea welding operations," explains Geir Ilsaas, project manager for the Gullfaks gas export line.
The new facility will be very important for Statoil as a gas exporter and for the group's Kårstø gas treatment plant north of Stavanger. Within a few years, Gullfaks will account for more than 50 per cent of the gas reaching Kårstø through Statpipe.
Lorelay is due to lay 350 kilometres of pipe for Statoil this season, including the three-week job on Gullfaks. Its next assignment will be the Norne and Heidrun gas export line in the Norwegian Sea.
This will run in a loop from Norne to the group's Åsgard transport gas trunkline and back to the Heidrun tension leg platform.
Finally, the barge will return to the Tampen area of the North Sea to lay a gas line from Statoil's remotely-operated Huldra platform to the Heimdal field operated by Norsk Hydro. All this work is due to be completed by September.