Stine subsea well SCB-1, located in the Siri Fairway in the Danish North Sea, was scheduled to be worked over in April 2012, to correct a malfunctioning subsurface safety valve.
Prior to the planned workover, EPConsult Energies were engaged to conduct a 'return to production' readiness review to assess whether there were any other issues which might prevent resumption of full production from the well.
The review confirmed the requirement to address several faults with the subsea production infrastructure identified previously, the most serious of which was a leaking flange in the multiphase line between the well and the host platform, Siri.
EPConsult Energies led a small project to analyse the cause of the leak, identify potential repair options, and manage the selected repair method.
Behaviour of the flange under various loading conditions was extensively modeled by our partners JP Kenny. From this analysis, it was concluded that the most likely cause of the leak was relaxation of the flange studs.
A DSV campaign to replace the flange studs by 'hot-bolting' thus avoiding ingress of seawater, successfully restored the leak tightness of the flange in April 2012 ahead of the arrival of the drilling rig.
The workover was successfully accomplished in June 2012 and the well was returned to full production.