Ormen Lange

Subsea rock installation helps Norway expand its gas production

Our client
Norway is one of the world's largest exporters of oil and gas. The country's Ormen Lange gas field is located approximately 120 km from the coast within a prehistoric slide area. This Storegga slide has water depths ranging from 250 to 1200 m. It's soil is irregular, varying from very stiff clay with boulders to soft clay.

As part of the country's expansion efforts, Norway decided to invest in a subsea tie back from two 8-slot templates to a shore terminal. Two 30" pipelines have been installed in water depths ranging from 850 m to the landfall. The developments of the subsea tie back to shore also required two 6" MEG injection lines and two control umbilicals. The Ormen Lange license group awarded Van Oord a subsea rock installation contract that supports these developments.

Our work
The rock installation contract comprised of the installation of rocks for support and protection of Ormen Lange's pipelines and umbilicals from shore at Nyhamna to the field development area. Rock installation was required before and after the installation of pipelines and umbilicals ("pre-lay" & "post-lay" respectively). The contract called for the procurement of 2.8 million tonnes of rock and the transport of the rock material from quarries along the coast of Norway.

Our result
The flexible fallpipe vessels Nordnes and Tertnes executed the works in different campaigns between 2004 and 2007. The works were completed in January 2008.