The pipeline-laying vessel LB200 today recommenced the laying of Langeled 33 km from Nyhamna and south towards Sleipner. From 2007 enough Ormen Lange gas to cover a fifth of the UK's needs will stream through the completed, 1200 km long pipeline.
Acergy’s LB200 picked up the end of the line laid last year by Solitaire 33 km from Nyhamna. Laying will continue in a south-westerly direction, towards Sleipner.
Laying north from Sleipner will start in August, when the dynamically positioned Allseas vessel Solitaire will be used. The pipeline will be laid in a north-easterly direction and it is expected that Solitaire will lay down its end if the pipeline in November. The two pipeline ends will be welded together in 2007.
The northern pipeline will come from Måløy, the middle part from CCB on Sotra, while the southern section will be supplied by Farsund. A total of 20,000 Langeled pipelines are in storage on Måløy, with 9,000 at CCB Ågotnes and 20,000 in Farsund.
Up to four km pipeline laid daily
LB200 is basically a huge pipeline factory, with four welding stations running the length of the ship. The pipelines are welded together and then given a protective coating. The welded joints are then subjected to ultrasonic testing before the pipeline is laid at a speed of roughly 4 km daily.
Between Sleipner and Easington the pipeline has a diameter of 44 inches, while it is 42 inches in diameter between Nyhamna and Sleipner.
Fishery vessels are asked to maintain a reasonable distance and be particularly aware that pipeline vessels can change position considerably from day to day. Specialist personnel will be on board when the vessel is working in fishery areas, and these can be contacted if need be.
Ormen Lange pipeline laying to start in summer
In the summer Solitaire will continue to lay the production pipelines out towards the Ormen Lange field, to a point half-way down the Storegga slide 100 km from Nyhamna.
Here the laying vessel S7000 will take over and lay the demanding final 20 km further down the slide and up to the templates at a depth of 850 meters. As this last stretch is so steep, S7000 will lay the pipes in a J-formation, i.e. two sets of four pipelines welded together and laid from a high tower structure on the vessel.
2,600 vessel days
Laying of the anti-freeze pipes, and the first of the two control cables out in the field, will also commence in the spring. In fact, the entire 120 km long control cable will be laid from one coil on board the Skandi Neptune from Subsea 7.
Remote controlled robots will later be used to place the cables in trenches on the seabed. The anti-freeze pipelines will be laid by Acergy’s Seaway Falcon. It will take a total of 2,600 vessel days in 2006 to put all the pieces into of the gigantic Ormen Lange project into place. This figure includes everything, from the massive laying vessels to smaller survey ships and transport craft.
Gravel dumping
Gravel will be dumped on the seabed to even it out prior to laying and to stabilize the pipeline afterwards. This work will be carried out on all pipelines and cable crossings, on areas where the seabed is uneven and where the pipeline must be stabilized and safeguarded against lateral displacement.
The main bulk of the work will take place on the northern half of the route. This will mainly be done after laying and will continue until 2007.
The southern part of Langeled will open in October of this year, so that gas from other fields on the Norwegian continental shelf can be exported to the UK and the Sleipner platform.
Hydro is operator for Ormen Lange and Langeled. As operator for Langeled, Hydro delegated project management responsiblity to Statoil. The project is manned by personnel from both companies. From 1 September the Langeled operator will be Gassco.