Gas leak halts production from Oseberg offshore Norway

March 18, 2013
A power outage this past Thursday at the Oseberg field center in the Norwegian North Sea led to a temporary gas leak, says operator Statoil.

Offshore staff

STAVANGER, Norway – A power outage this past Thursday at the Oseberg field center in the Norwegian North Sea led to a temporary gas leak, says operator Statoil.

The leak occurred from a well on Oseberg B. It has been stopped, but the field center has since experienced additional power supply problems, and oil and gas production remains shut in.

After the first incident report, the facility was shut down in line with procedures, the emergency response organization was mobilized, and personnel on board mustered to the lifeboat stations.

Power was restored, but during the subsequent start-up, gas detectors on Oseberg A indicated that gas was present. An alarm was triggered once more some time later, the facility was depressurized, and personnel once more mustered to lifeboats. The gas detectors quickly returned to normal levels, and the situation appeared to be resolved.

However, another power failure then occurred on the field center with loss of main power, which was eventually restored. Measures were additionally initiated to safeguard personnel on board, as the heating unit was not in operation.

Floatel Superior is stationed at the field center, which is undergoing a heavy program of work. The floatel provides space for additional personnel. At present, there are about 700 people at the center, including those on the floatel.

Due to the disruption, some floatel personnel involved in maintenance, modification, and other tasks will be flown to the mainland to provide room for staff from Oseberg A that are working to bring the facility back onstream.

The aim is to restore a stable main power supply on board so that the heating unit can be started, personnel can be taken on board, and activities resumed.

The Oseberg field center comprises the bridge-linked Oseberg A, B, and D platforms. Oseberg A is a concrete platform with process equipment and living quarters; Oseberg B has a steel jacket with drilling, production, and injection equipment; and Oseberg D is a steel platform with gas processing and export equipment.

3/18/2013