Petroleum Safety Authority Norway : Audit of Gullfaks subsea compression

In 2015, Statoil began operation of a subsea facility for compression of wet gas from Gullfaks Sør. The gas is transported through a 15-kilometre-long pipeline to Gullfaks C for processing. As the pressure in the reservoir falls, the facility will help maintain production and thereby increase the field's utilisation rate. The facility was the first of its kind in the world.

The subsea facility is controlled from Gullfaks C using a control cable on the seabed. This cable carries electrical power, signals and chemicals through a shared outer sleeve.

Due to an incident involving this cable, which caused a chemical spill, the PSA has carried out an audit of Statoil's follow-up of the incident, and the design engineering and manufacture of a new control cable. The audit paid particular attention to Statoil's follow-up of the incident, management of the supplier and lessons learned from the incident.

The audit was conducted in the form of meetings on 17 November 2016 at Statoil in Bergen and on 1 December 2016 at Nexans, the supplier, in Halden.

The audit detected no regulatory non-conformities.

However, improvement points were found relating to remits, authorities and division of responsibilities.

Statoil has been given a deadline of 7 February 2017 to report on how the improvement points will be assessed.