There were 311 people on board, and no one was injured during the incident.
The Oseberg A platform in the North Sea. (Photo: Harald Pettersen)
The production on the Oseberg field centre is now shut down. The authorities have been notified.
The Oseberg field centre includes the three Oseberg A, B and D platforms, which are bridge-linked in the southern part of the field, and Oseberg C, which is located 14 kilometres north of the field centre.
Oseberg A is a concrete platform with processing equipment and living quarters, whereas Oseberg B has a steel jacket with drilling, production and injection equipment.