Workers have been taken off Shell's Nelson platform in the UK North Sea following a power outage on Tuesday.
It has also emerged that one of the helicopters flying workers off the facility had to make an unplanned landing on Apache’s Forties Delta platform when a warning light was displayed.
A Shell spokesperson said non-essential staff were taken off Nelson to the nearby Borgholm Dolphin flotel after the platform lost power.
Nelson, located about 190 kilometres east-north-east of Aberdeen, has been shut down for maintenance and was not producing oil or gas.
The spokesperson said: "Shell UK can confirm that there was a power outage yesterday on the Nelson platform. Work to restore main power on the platform continues with essential staff on board."
The spokesperson added that staff will be transported back to the Nelson platform or to Aberdeen over the next 48 hours.
"There are no reports of any injuries as a result of this outage. The relevant authorities have been informed," she added.
A post on an oil workers' social media page, apparently from a worker on Nelson, said: "Lights went out at 6am on Nelson, emergency generator kicked in but 15 mins later shut down again. A couple of attempts were made to restore power, but no joy.
"First chopper of nine arrived at 2.30pm to downman us to the flotel."
The post also said one helicopter was forced to make an emergency landing on Apache's Forties Delta platform due to a warning light.
"All crew from that chopper eventually made it to the flotel. Essential personnel are still on the Nelson," the post said.
This was later verified by Shell.
The spokesperson said: “The helicopter was diverted after a warning light was observed by the pilot. It landed safely on the Forties Delta platform which is nine miles (15 kilometres) away from the Nelson platform. Personnel were then transferred from the Forties Delta to the Borgholm Dolphin on a subsequent flight with an alternative helicopter.”