More than 80 North Sea workers have been evacuated from a production platform after a leak was discovered in a leg of the installation.
Work is under way to fix the leak on Brent Bravo
Sixty staff remained on Shell's Brent Bravo platform and work was under way to repair the leak.
The alarm was raised on Sunday night when staff reported a release of oil from the platform's utility leg.
A spokesman for Shell said 85 non-essential workers were flown to neighbouring installations.
A controlled shut down of production has been carried out in order to repair the leak.
Shell insisted only a very small amount of oil was involved and there had been no escape of gas.
Offshore union leaders have expressed concern as Shell was recently fined £900,000 for a breach of health and safety on Brent Bravo, following the death of two offshore workers.
They were overcome by gas in the same utility leg, which is used to store equipment and gain access to operations below sea level.
A fatal accident inquiry into that incident has still to be held.