Norwegian firm Statoil is expected to begin an investigation after a gas leak occurred on the Heimdal platform in the North Sea on 26 May.

The Heimdal Gas Center, on Production License 036, is an offshore natural gas field, located 212km northwest of the Stavanger and located at a depth of 120m, the platform serves as a connection hub for processing and distribution of natural gas from satellite fields.

Gas leak occurred during the testing of emergency shutdown valves at the platform, which was not on stream due to a shutdown for maintenance, field operator Statoil said.

However, there were still pressurised systems in areas not included in the turnaround.

Standby vessels and helicopters were dispatched to the area as the operator mobilised its onshore and offshore emergency response organisation.

The 98 personnel onboard the platform were transferred to lifeboats in accordance with the emergency instructions, but returned to their normal tasks later the same day.

No one was injured in the incident, which Statoil said was serious and provisionally classified as Red 1.

Norway’s Petroleum Safety Authority will also investigate the leak, Statoil said.

This incident is subject to internal investigation in Development and Production Norway.

Statoil (39.44%), Centrica Resources (23.79%), Petoro (20%), and TotalFinaElf Exploration Norge (16.75%) are the partners in the project.