Experiences with an offshore pipeline project for the North Sea (Langeled)

This paper gives an overview about the Langeled Project, which will result in the longest offshore pipeline in the world. The Langeled pipeline will transport natural gas from Nyhamna on the Mid West coast of Norway via the offshore platform Sleipner to Easington in England. Unprocessed gas is transported by two 30”OD pipelines from the Ormen Lange field at about 1000m water depth outside mid-Norway to the gas terminal at Nyhamna, where the gas is treated before it is sent through Langeled as the first pipeline bringing gas from Norway directly to the U.K. The length of the pipeline is about 1200 km and close to 1 Million tonnes of steel pipe will be produced. For Langeled North the constant ID is 1016 mm (42”OD) and for Langeled South 1066 mm (44” OD). Wall thicknesses between 23.3 and 34.1 mm are required. The design of the pipeline is according to DNV standard OS F 101. The material grade is SAWL 485 IFD. EUROPIPE supplied 835 km or 630,000 tons of pipe to the project. About 800 km were produced in Mülheim and the remaining portion, or 35 km in Dunkerque pipe mill. Pipe production started in April 2004 and finished in December 2005. Lots of around 30,000 t per month had to be shipped to Norway to receive corrosion and heavy coating. The paper will summarize the pipe production and the logistical challenges. (AU)