Two workers were airlifted from EnQuest’s Heather Alpha platform following a small fire on Monday.
The fire was quickly extinguished and the platform, about 145 kilometres north-east of Shetland, was made safe, an Enquest spokesman said on Tuesday.
He declined to confirm the cause of the fire.
Both injured persons have already been released from hospital after an assessment.
The platform was already shut in for pre-planned maintenance reasons and remains offline.
“EnQuest is liaising with all relevant authorities as part of its response to the incident, and a detailed investigation into the cause is being undertaken,” the spokesman said.
A total of 128 personnel were on board.
A worker was airlifted to hospital on Monday following a separate fire on Taqa's Tern Alpha platform.