On 4 and 5 October 2018, we carried out an audit of the operation and maintenance of, and barriers for, the subsea facilities at Norne. The audit also targeted the operating life assessments made in connection with Equinor’s application for a life extension for Norne.


The objective of the audit was to obtain a description of the challenges associated with barriers, condition monitoring and operation of subsea facilities at Norne, and how they are followed up. We also wanted to examine the preconditions for extending the operating life of this equipment.

The audit focused on subsea facilities at Norne, looking primarily at the subsea templates and associated manifolds and christmas trees.

The following topics were reviewed:

  • Organisation of the life extension study
  • Availability and quality of the documentation
  • System review and identification of degradation mechanisms
  • Statistics, experience and probable failure modes for relevant components
  • Review of historical operational data and establishment of residual life of components
  • Deviations from design criteria
  • Identification of risk
  • Quality control of findings and recommendations
  • Operation and maintenance of the subsea facilities
  • Overview of statuses of barriers associated with the subsea facilities


The audit identified one non-conformity relating to compliance with internal requirements and three improvement points relating to maintenance of the subsea facilities, procedures for testing of well valves and shutdown of subsea wells.

What happens now?

We have asked Equinor to report by January 2019 on how the non-conformity will be addressed. We have also asked the company for their assessment of the improvement points we observed.