Coastguard helicopters were mobilised to take 76 non-essential workers off BP’s Bruce installation off Aberdeen late on Thursday evening.
They were transferred to other platforms in the area.
The coastguard said that 45 workers remain on the installation.
A coastguard spokesman said: “Following a loss of power on the Bruce platform off Aberdeen late on Thursday 22nd June, HM Coastguard rescue helicopters from Shetland and Inverness were tasked to partially down-man the platform.
“76 non-essential personnel were transferred overnight by helicopter to other platforms in the area.”