Statoil’s Polarled gas pipeline crosses Arctic Circle
STAVANGER, Norway -- Statoil's Polarled gas pipeline crossed 66 degrees and 33 minutes north of the equator on Friday morning, and, in doing so, it became the first pipeline to take Norway’s gas infrastructure across the Arctic Circle. The pipeline will open a new gas highway from the Norwegian Sea to Europe.
The 482-km long, 36-in. wide pipeline will run from Nyhamna, in western Norway, to Aasta Hansteen field in the Norwegian Sea. The world’s largest pipelaying vessel, Solitaire from Allseas, is carrying out the job and is advancing slowly, exactly 24.4 m at a time, every sixth minute or so, around the clock.
During the start-up in March, the pipeline was pulled in to Nyhamna. During September, Solitaire will arrive at Aasta Hansteen field, if the weather permits. Even early in the autumn, high waves and strong wind leading to interruptions must be expected.
“We are progressing well at the moment, conditions have been good for more than 50 days in a row, and at the end of July we set a record of laying 4.8 km of pipe in one day,” Kenneth Aksel Kristensen, one of Statoil’s company representatives on board the Solitaire, said.
Polarled will also be the deepest pipeline on the Norwegian Continental Shelf—by the time the vessel reaches Aasta Hansteen field, the water depth is 1,260 m. Furthermore, it will be the first time that a 36-in. pipeline has been laid in such deep waters anywhere in the world.
Solitaire is a huge, well-oiled pipelaying machine, which needs a constant supply of pipes. Every pipe is 12.2 m in length, and the vessel is laying around 4 km of pipe a day. This means that the Solitaire needs a supply of more than 300 pipes a day, enough to fill two to three boats.
When a pipe is lifted on board the Solitaire, it enters a huge assembly line. The pipe is sent from station to station, through the factory of the 397-m long and 41-m wide vessel, where specialized operators perform their tasks.
To complicate matters, the pipeline is not being laid in a straight line.
“We have examined the seabed thoroughly in advance to find the best route and also to avoid corals and large rocks,” said Arne Fosse, Statoil’s head of the Polarled construction work.
At start-up, gas from Aasta Hansteen will be the only gas passing through Polarled, but the pipeline has capacity for more.
“We have therefore installed six connection points, call it future slip roads to the new gas highway,” Håkon Ivarjord, Statoil’s project venture manager for the Polarled development project, said. “Polarled will open up for gas export to Europe from a completely new gas province, and with the infrastructure in place it will also be more attractive to explore the surrounding area.”
The Solitaire's crew is working around the clock. It takes around 90 minutes from a pipe being lifted on board and entering production until it has become part of the ever-extending Polarled pipeline. There are 410 people on board the vessel, including two asset owner representatives from Statoil and eight people from DNV GL—who are also part of the day and night operation.