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Ageing and life extension

Both the Petroleum Safety Authority Norway (PSA) and the industry have initiated a number of activities linked to ageing and life extension on the Norwegian shelf.

The challenge is to document adequate safety in connection with continued operation of older facilities and pipelines.

The lifetime of a facility is described in connection with delivery of the PDO (Plan for Development and Operation); and/or it is stipulated as a basis for the facility design.

Normally, all parts and components* of a facility will be designed so that there is little chance of failure during the course of the planned lifetime. If all of the individual parts and components have sufficient lifetimes, then the facility as a whole will also have a sufficient lifetime.

* Components cover all types of equipment, pipes in the process facility, pressure tanks in the process facility, structural steel, crane beams on cranes, well casing, etc.

In connection with life extension, these principles must in many cases be exceeded. Individual parts and components can no longer exhibit the desired low likelihood of failure in the extended years, based on design standards.

At the same time, the companies have built up many years of experience with these parts and components through practical use, and know how they have functioned and whether they may have been weakened by corrosion, wear, fatigue or other degradation mechanisms.

In addition, one can evaluate what could happen if one of these parts fails - will this lead to catastrophic results, or is there sufficient overall robustness that such a failure can be tolerated until the part or component has been repaired? These are important questions in connection with lifetime extension.

Growing challenge on the Norwegian shelf
According to the regulations, the operator must obtain consent prior to using a facility beyond the basic lifetime described in the PDO application (Section 5 f of the Information Duty Regulations).

The regulatory requirement, introduced in 2002, also states that the operator must send the application for consent for extended lifetime one year prior to expiration of the planned lifetime. This is because we expect considerable case processing work in this area and we therefore need ample time to evaluate the applications.

Our expectations regarding the operators is that they address the entire facility and document sufficient safety for continued operations beyond the expected lifetime.

Approximately ten facilities on the Norwegian shelf are between 20-29 years old, while a handful are older than 30 years. The lifetimes of these facilities had expired before the new regulatory requirement was introduced in 2002, however, the operators have initiated work following pressure from the PSA to evaluate the various risk factors associated with continued operation.

Projects in the PSA and the industry
In early 2006, the PSA established a multi-disciplinary group with the objective of coordinating activities related to aging and lifetime extension. The work has consisted of identifying and mapping the aspects of aging that reduce a facility's safety. Particular focus has been placed on main safety functions and the risk of major accidents.

We have also asked the Norwegian Oil Industry Association (OLF) to map and identify important challenges, and have encouraged the industry to develop norms (standards) in the area of aging and lifetime extension.

The initiative has resulted in comprehensive work in a number of areas, including management of the process to submit applications for consent for lifetime extension and other specific technical areas such as structures and pipelines.

The Petroleum Safety Authority Norway has been in touch with other industrial sectors such as the nuclear power industry to see how it deals with lifetime extension and aging issues.

We are also cooperating with the authorities in a number of other countries, drawing on experience from e.g. the British HSE authorities in this area. (Ref. overview of technical reports for downloading in separate link box).

We are doing all of this because we believe it makes good socioeconomic sense to use old facilities as long as they are safe, rather than condemning the facilities and stopping production or building costly new facilities far too early.

Relevant articles on aging and lifetime extension:

Contacts in the PSA: