About 100 workers were evacuated from an oil platform in the bay of Rio de Janeiro after it began to tilt.
The port captain's office said an inclination of three degrees sparked the evacuation on Saturday night.
It added that no petroleum leaked from the platform, owned by the US firm Transocean, and no one was hurt.
The statement said the platform was undergoing maintenance when the problem was detected.
The tilt was caused by water entering a platform pillar, and it was later corrected.
Transocean did not immediately respond to a request for comment.