This paper describes the role of longitudinally electric fusion welded (EFW) Super Duplex Stainless Steel Linepipe supplied by H.Butting GmbH & Co kG and United Pipelines Limited for the subsea production flowlines in the development of the Shell U.K. Exploration and Production Kingfisher Field, which were installed using the Reel Lay System by McDermott Marine and Construction Limited.

The paper considers the material selection criteria adopted by the project team. The size range of the linepipe supplied is presented, along with project specification requirements adopted by the project for the manufacture and fabrication of EFW Super Duplex Stainless Steel linepipe. It outlines the production route for the manufacture of longitudinally electric fusion welded Super Duplex Stainless Steels and discusses certain key manufacturing operations which includes, plate manufacture, welding of seam and jointer girth welds and hydraulic expansion. The project required an extensive programme of mechanical and corrosion testing to demonstrate the suitability of Super Duplex Stainless Steel linepipe for installation by the 'Reel Lay System' technique. The paper presents a summary of the pre-production test results on the linepipe, which includes mechanical and corrosion test results on linepipe subjected to a simulated reeling trial, necessary to demonstrate the suitability of longitudinally electric fusion welded Super Duplex linepipe to the Reel Lay System. Details of the insulation coating on the EFW Super Duplex Stainless Steel linepipe are presented. The methods of fabrication adopted by the Kingfisher Project Team at site are also discussed.