NO5-A

Offshore pipelay
Lorelay
Lorelay next to N05-A platform

Installation of 15-kilometre shallow water pipeline for the flagship N05-A natural gas development in the Dutch North Sea.

ONE-Dyas

Schiermonnikoog, Dutch North Sea

Water depth: 10 - 26 metres

Pipelay scope for largest Dutch offshore natural gas development in 15 years

Start-up in 10 metres water depth close to live assets

Scope of work

  • Pre-lay & post-lay surveys
  • Installation of crossing mattresses and post installation rock berm
  • Transport & installation of 14.6-kilometre, 20-inch shallow water pipeline
  • Trenching the pipeline (to 0.8 metre Top of Pipe)
  • Flooding, cleaning, gauging & testing
  • Burial of pipeline heads
Our Dolphin operating team

Specials & challenges

  • Pipeline start-up in 10 metres water depth close to live assets.
  • Start-up pile installation and recovery
  • Strong tidal currents
Pipeline start-up in 10 m water depth
Buoyancy applied to 'lift' pipeline and reduce weight
In-house NDT system 'Dolphin' used to scan welds
Lorelay installed the 15-km, 20-inch concrete-weight coated pipeline
Allseas' scope included trenching the pipeline to 0.8 metre TOP
Project took a couple of weeks to safely complete
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