BRONDBY, Denmark -- The last of four new multi-purpose risers for Statoil’s Veslefrikk field should be installed this spring, according to supplier NKT Flexibles.
Statoil awarded the contract for the Norwegain North Sea project in June 2008, and delivery was completed last September. It comprised four 8-in. (20.3-cm) ID flexible risers for use in high- and low-pressure oil production, oil export, gas injection and export, and water injection.
The double-catenary, free-hanging dynamic risers connect the Veslefrikk A jacket to the Veslefrikk B semisubmersible platform. Statoil needed to replace the existing risers which had to be taken out of service due to rupturing of the outer sheath possibly caused by excessive temperature build-up beneath the bending stiffener.
To resolve the problem, each new riser top end was bonded with a vulcanized wear protection layer. This solution is designed to shield the outer sheath from atmospheric exposure, and to lower the contact temperatures between the bend stiffener and the riser surface.
Acergy Norway installed the first three risers in October, and all currently are in full service. The last riser is in a spare slot at Veslefrikk awaiting installation.
In June, NKT expects to supply the first batch of 6-in. (15.2-cm) ID flexible pipes ordered by Petrobras under a three-year frame agreement. In line with Petrobras’ specifications, the pipe will be delivered on yellow reels, smaller than those normally used by NKT. The customized reels were manufactured by UAB Marine Technology in Lithuania.
Statoil overhauls Veslefrikk risers
The last of four new multi-purpose risers for Statoil’s Veslefrikk field should be installed this spring, according to supplier NKT Flexibles.