OSLO, Norway – Petroleum Safety Authority (PSA) Norway has issued an alert to operators of mobile facilities on the Norwegian continental shelf.
This follows PSA’s investigation of a stability incident affecting the Floatel Superior 7 mobile accommodation rig on Nov. 7 while on location at the Njord field. This has revealed a potential risk of damage to anchor bolsters.
The warning reads as follows: “Damage has been discovered to bolsters where anchors are attached on a semisubmersible facility which has sailed under its own power from the Far East to Norway and has subsequently been kept on location by dynamic positioning.
“The damage is thought to have arisen because the anchors have moved horizontally and vertically as a result of wave motion during transport, operation and at survival draft, and have repeatedly inflicted damage to the contact surfaces and the lower bracing members.
“In the event that a bracing breaks, the damage can escalate so that more parts of the bolster are torn off. Anchors would then hang free. In rough seas, this could cause great damage to support column and pontoon, with loss of watertight integrity as a possible consequence.”