Chapter 25. Inspection and Maintenance of Ageing Concrete Oil and Gas Structures on the Norwegian Continental Shelf

Inspection and maintenance of the concrete Oil and Gas structures on the Norwegian Continental Shelf is a current focus area for owners and regulators. These ageing structures were installed between 1977 and 1995 and have been in operation in harsh environmental conditions throughout, and in some cases exceeding, their design service life. This paper results from work undertaken to describe repair methods and experience of repair works on the Norwegian Continental Shelf on ageing offshore structures. The part of this work related to inspection and maintenance of concrete structures forms the basis of this paper.

Current experience shows that several concrete structures have a backlog of anomalies requiring assessment and possible remediation due to an acceleration of degradation over their lifetime. An increased frequency and range of defects means that stakeholders are expanding their capabilities to best manage these developing challenges.

Maintenance of concrete structures demands an understanding of the degradation mechanisms, repair history, and original design requirements. A robust remediation management strategy should be followed to ensure a consistent and structured approach to all phases of the process, from inspection to documentation of remedial works.

This paper aims to provide an overview of current experience and proposes a suitable remediation management strategy framework for offshore concrete structures.