Page 26: of Offshore Engineer Magazine (Sep/Oct 2020)

25 27

FEATURE SUBSEA PIPELINE key technology providers including Sin- ture (services) and Subsea 7 or Technip- down to 1,000 meters, and hyperbaric tef, Isotek, Connector Subsea Solutions, FMC (vessel and diving services). (TIG) welding equipment contained in

Applus RTD, and NUI, with STATS “It also contains some very unique 100-tonne one-atmosphere habitats (for

Group and TDW Offshore Services equipment,” says Berge. There’re clamps divers to work in) for 8 – 48in pipelines providing pipeline isolation services, (for small repairs), connectors, including down to 180 m water depth (the diving and contracts and frame agreements remote installed MORGRIP connectors limit in Norway). with a Technip-DeepOcean joint ven- (10 – 30in), for replacing sections of pipe There’s also all the ancillary equip- ment needed to deploy these systems from coating and weld seam removal and cutting tools to huge hydraulic operated (with seawater and electric power from the surface) pipeline handling frames.

World’s firsts in pipeline repair

Two of the latest innovations in the pool is the world’s only fully remote diverless retroft hot tap system and the pipeline (MIG) welding equip- ment spread. The latter was qualifed in 2014 and tested down to 1,000 meters in a Norwegian fjord, after major in- vestment to enable diverless welding – therefore allowing welded repairs in wa- ter depths deeper than 180 meters and above the pipe diameter the connectors can do (>30in). But it’s only just been used for the frst time, last year (2019), in a world frst, on the Johan Sverdrup feld for a planned tie-in of the oil ex- port pipeline to the platform.

The system contains a complete set of tools required for a hyperbaric tie-in or repair and includes a habitat that pro- vides a dry and inert atmosphere around the tie-in point, a gas metal arc welding (MIG) tool that includes a pre- /post- weld heat treatment system, welding consumables and a welding tip changer for long-duration welding. Pipeline joints are made through sleeve joints which are then flled in with fllet welds to make up the joints, as it was seen as

A pipe lifting frame at the quayside undergoing functional testing before deployment. 26 OFFSHORE ENGINEER OEDIGITAL.COM