Company spokesman Ole Anders Skauby said that most of the 374 people on the "Floatel Superior" were airlifted by helicopter after one of the floating pontoons started taking on water, causing the structure to list. The company was notified about the problem in the early hours of the morning.
Some security staff stayed on the accommodation rig to stabilize the platform. There was no immediate danger to the life and safety of the workers, Skauby said.
Statoil said oil production was not affected as the oil field had been closed for maintenance.
The Njord field, named after a Norse god, is located some 130 kilometers (80 miles) northwest of the city of Kristiansund off the Norwegian coast.