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Long life demands hard work

Installations on the NCS are getting steadily older. The question is what implications this aging process has for major accident risk.




This article was originally published in
Safety - Status and Signals 2012-2013

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A great many Norwegian offshore facilities are reaching the end of their original design lives. Roughly half have already passed that point, with another 20 due to follow during the coming decade.

That will call for rigorous efforts to prolong the working lives of platforms, mobile units and pipelines, since achieving such extensions offshore is no easy matter.

Outdated
Metal can corrode, structures weaken, systems become outdated. Increasing age also boosts the probability of faults arising in components and equipment.

Over time, a gap may develop between the actual and required condition of a facility in terms of structure, technology, systems or the working environment.

The question is then where the line should be drawn, and how long it will be possible to rely on safety staying sufficiently acceptable.

“Our absolute requirement is that every facility must comply with the regulations at all times,” says Gerhard Ersdal, who heads the PSA’s follow-up of aging and extensions to producing life.

“Some aspects are particularly important in this perspective. Degradation of steel and other materials is a key problem on older installations, for example. “Many of the elderly facilities also have aging equipment, which can become outdated long before its design life expires. That may complicate both operation and maintenance.”

He points out that it can be increasingly difficult, for example, to source space parts for venerable equipment and components.

“Using equipment based on older solutions can be demanding, and poses problems at the interface between humans, organisation and technology.

“It’s important to ensure that the expertise required to run and maintain vintage equipment and systems is available. And old hardware must be compatible with new facilities.”

Maintenance strategies very often need to be changed on an elderly installation, he adds, and points out that equipment also has to be modified and replaced.

“Aging mechanisms such as corrosion, decay of coatings, deposition and sediment in process equipment, and subsidence of fixed installations are key challenges.”

Both individually and collectively, upgrading, modifications, maintenance and enhancing expertise can affect major accident risk. So operators must tackle the challenges and give priority to these four areas, says Ersdal.

“With good management, it’s fully possible to keep facilities in satisfactory condition.”

Goals
Aging and extending producing life were defined as one of the PSA’s main priorities in 2006-09, and many of its goals for this commitment were met during these years. That included such aspects as standardisation, the development of common guidelines and methodologies, and the build-up of the necessary knowledge.

The industry’s know-how about aging facilities has accordingly increased in line with the number of these units, and this area was dropped as a PSA main priority in 2010. By then, the industry had broadly incorporated the issue in its activities in a positive way. The PSA instead adopted a focus on barriers.

As part of the latter, however, the authority will be checking in 2013 that companies are monitoring barriers throughout the economic life of their facilities. The government will also be contributing to a strengthening of the industry’s work on extending producing life, and encouraging cooperation and experience transfer between the companies.

“We’ve also established a collaboration with the UK’s Health and Safety Executive,” reports Ersdal. “Following our work with aging and extending producing life, our British counterpart adopted this issue as a main priority a couple of years ago.

“That means we get information on findings by the UK, can calibrate these with developments on the NCS, and compare the data with what we learnt in 2006-09.”

Consent
A requirement that operators must apply for government consent to use a facility beyond its original planned economic life became part of Norway’s regulations in 2002. An application must include an analysis and assessment of HSE for the activities and facilities concerned, and describe action to meet and maintain regulatory requirements. The overriding stipulation is that the threat of a major accident on a 30-year-old installation must not be higher than for a brand-new facility.

Although the PSA sees that extending producing life poses many challenges, it is confident that the companies are complying with their obligations and meeting the safety requirements. It follows this up with the industry.