UK North Sea operator EnQuest is considering removing a damaged susbea crude oil storage tank as a way of remedying the structural problems at its ageing Thistle Alpha platform that led to the sudden evacuation of all 115 workers on board last week.

EnQuest said on Thursday Thistle Alpha remains shut in as it works with its suppliers and partners to develop a remediation plan but cannot predict yet when this might take place.

Upstream, meanwhile, can reveal further details about the problems with that supporting structure of the tank that forced the operator to call in coastguard helicopters to take workers off the 43-year-old facility, located 200 kilometres north-east of Shetland in Block 211/18, on 21 October.