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Many challenges for ageing installations

Lack of knowledge, standards and clear-cut procedures are some of the challenges the petroleum industry is facing as the lifetime of an increasing number of facilities on the Norwegian Shelf is extended. This emerged at a seminar on ageing and lifetime extension organized by the Petroleum Safety Authority Norway (PSA) on Wednesday, 19 November.

The seminar was held as a result of extensive work done by SINTEF on documenting routines, standards and risk related to lifetime extension. Many of the facilities have reached the lifetime they were originally designed for, but are still in operation and will continue to be so. An extended lifetime shall not be at the expense of safety related to health, the environment and economic assets.

At the seminar the SINTEF researchers, Per Hokstad and Roy Johnsen, stated that current standards are unclear, non-uniform and not very systematized with regard to lifetime extension. They advocated an extensive, general and inter-disciplinary project to develop common procedures and standards for application in this area. The system must be rule-based, and thorough documentation, experience and know-how must form the basis for evaluating whether a facility shall be granted a lifetime extension.

The SINTEF report outlines a schedule in several stages where the first stage is to clarify which systems need to be evaluated and obtain information on the facility’s structure, history and current operating situation. This information must be quality-assured. Consideration must be given to how the facility is to be operated in the future in respect of potential changes that may affect safety.

All components in offshore facilities are subjected to stress which wears down materials, equipment and units over time. The degradation sometimes occurs faster than we think. It is therefore necessary to monitor the facilities closely, conduct frequent inspections and testing, and have clear-cut routines for replacement, maintenance and repairs.

Lifetime extension must not lead to an increased risk of accidents or challenge critical safety barriers. There is currently a lack of knowledge and technology for monitoring degradation mechanisms, particularly as regards wells, pipelines and subsea facilities. The SINTEF researchers believe there is a need for developing better models that describe various degradation processes. Problems may arise when old and new equipment is to be combined. It is also important to ensure that competence is safeguarded and utilised.

The challenge of ageing and lifetime extension was also the topic of a panel debate at the seminar. An account was given of experience from the British sector, and working environment challenges on ageing facilities were illuminated.

Contact in the PSA:
Gerhard Ersdal
E-mail: Gerhard.ersdal@ptil.no