Experts have this week been struggling to stabilise a North Sea oil well 120 miles east of Shetland.
The problem started with a sudden rise in gas pressure under the seabed, forcing Norwegian operators Statoil to evacuate 89 workers from the platform six days ago. The company said it could be days until the Gulfaks C well, which lies in Norwegian waters, can be safely capped.
Although the risk of a spill in the waters east of Shetland is thought to be very low, Norway’s safety regulators said the incident had been “serious”.
Tonnes of specialist drilling mud have been pumped into the Gulfaks well in a bid to contain pressure, and Statoil is attempting to cap the well with cement.
A spokesman said: “The pressure is still unstable, but the situation has not worsened. We are continuing to work to normalise the situation.”
He added that no leaks had so far been detected and the company “deems the risk of a blowout as very small”.