Seabed, depth issues to complicate Polarled pipelay

Jan. 17, 2013
Statoil (OSE:STL) has contracted Ramboll Oil & Gas for detailed design of the 36-in. Polarled pipeline in the Norwegian Sea.

Offshore staff

COPENHAGEN, Denmark – Statoil (OSE:STL) has contracted Ramboll Oil & Gas for detailed design of the 36-in. Polarled pipeline in the Norwegian Sea.

Ramboll will additionally perform detailed design for the 30-km (18.6-mi) 18-in. Kristin gas export pipeline connecting to the Polarled system.

The project, so-called because it crosses the Polar circle, will open up infrastructure farther north in the Norwegian Sea. It is designed to safeguard future transport capacity for gas from planned or future field developments such asAasta Hansteen, Linnorm, and Zidane.

The Polarled pipeline will be installed in a water depth of 1,300 m (4,265 ft), a new world record for deepwater large-diameter pipelay. But according to Ramboll, this poses unique challenges during the installation where the pipeline will be free hanging from the installation vessel down to the seabed.

The pipeline will be installed on extremely uneven seabed characterized by very large ice scours. This will necessitate numerous long free spans where the pipeline will require rock support or removal of peaks, using specialized deepwater seabed intervention equipment.

Ramboll engineers in Denmark, Norway, and India will work on the project.

1/17/2013