High-strength tethers selected for Knarr risers offshore Norway
NOV Flexibles has contracted Lankhorst Ropes to supply Lankoforce riser tethers for BG’s Knarr field development in the Norwegian North Sea.
The field is being developed with anFPSO in 410 m (1,345 ft) of water in the North Tampen region.
According to Lankhorst, the tethers will be the first to use Dyneema DM 20, a high modulus polyethylene (HMPE) rope, for permanentsubsea anchoring of flexible risers.
Each of the Knarr development riser tethers consist of two HMPE tethers connecting a hold-down clamp with an anchor, allowing rotation around two axes.
The tethers incorporate a Lankoforce rope construction with a 12-strand braided Dyneema DM20 rope core, which provides the stipulated strength and mechanical performance. The entire rope core is protected by a braided polyester jacket and polyurethane coating, and includes ROV handling points for installation purposes.