Snøhvit lines in place
Pipelines and umbilicals connecting subsea installations on Statoil’s Snøhvit field in the Barents Sea with the process plant on land have been laid on schedule and below budget.
Just over 723 kilometres of these links had been laid when the Apache reel layer completed installation of the last two pipelines on 24 September.
In addition come infield pipelines and umbilicals linking the various installations on Snøhvit itself.
“The pipelaying programme has been completed as planned, and we’ve also delivered this work at less than the forecast cost,” says Gunnar Myrebøe, offshore manager for the Snøhvit development.
Work began in mid-April on installing a total of five links, including the wellstream pipeline and the umbilical for power and control signals.
In addition come two pipelines for chemicals and one for carbon dioxide being returned to the field for injection beneath the seabed.
The pipeline for multiphase flow of the wellstream and the umbilical both rank as the longest installations of their kind in the world.
Technology developed for these two facilities makes it possible to transport unprocessed production over long distances and to control subsea field installations remotely from land.
All infield flowlines, the wellstream pipeline and the carbon dioxide line have been pressure-tested with water without any leaks being observed.
“That demonstrates the high quality of the work done to install and connect the pipelines to the subsea structures,” says Olav Hagland, manager for this part of the Snøhvit project.
Some connection work remains to be done on the field, along with a good deal of trenching and gravel dumping along the pipelines.
The job of projecting the lines against fishing activities is due to be completed during the coming winter.