Turning point for maintenance

A serious incident in 2016 changed the thinking about look after equipment surfaces at the Mongstad plant.

Mongstad at 13.10 on 25 October 2016: 
A leaking valve is detected during repairs to a gas pipe at the plant. An operator enters the area and climbs scaffolding, locates the valve and tries to close it. That proves difficult.  

Havtil's investigation report stated:
“At 13.10.29, operator 1 took the valve key and gave the valve a light rap. He suddenly found the valve and pipe end in his hand, hanging by the key. The gas flow from the one-inch pipe end hit the scaffolding floor half a metre from the fracture site. Those standing nearby describe a “infernal noise” from the gas flow.” 

A serious gas leak was now a reality. The operator knew that the gas could ignite spontaneously and escaped to safety. All employees are evacuated and production shut down.  

Learning 

Nobody suffered physical injury in the 2016 Mongstad incident, although this was probably down to luck. The incident nevertheless triggered hectic activity at Mongstad – and at Havtil. 

“In this case, the potential for a fatal accident had been so great that we quickly decided to investigate,” says Kjell Arild Anfinsen, supervisor for onshore facilities at the authority. 

He remembers the incident well for several reasons, including the potential consequences and what the accident and subsequent investigation revealed. 
Havtil's investigation was detailed and identified many learning points, not least a lack of recent surface maintenance. Anfinsen believes the incident was a turning point for thinking about the latter activity. 

Storm 

At Mongstad itself, maintenance manager Kjartan Storsæt was in the heart of the storm. He has worked in many roles at the facility since joining it as an apprentice in 1992, and knows both the plant and the business well. 

And, not least, he knows the people. 

“An incident like this unavoidably affects you personally,” Storsæt says. “The operator concerned could have died. Having employees so closely faced with risk affects me and the whole organisation.” 

A major rehabilitation project was under way at Mongstad when the accident occurred, and Equinor had already worked to identify corrosion under insulation (CUI). The incident and investigations by Havtil and Equinor made it clear that change was needed. 

“Where Mongstad was concerned, the accident was an eye-opener with regard to shortcomings in barriers and surface maintenance,” says Storsæt.  
Many and far-reaching measures were taken, he adds. “We initiated a two-phase process, starting with immediate action and followed up through a longer-term process.”  

Inadequate 

Investigations by both Havtil and the operator concluded that surface maintenance at the facility had been inadequate over time, which permitted the pipe end to fracture and cause the leak. 

“So putting a crystal-clear safety-first stamp on the entire organisation was important,” says Storsæt. “A key aim in the first phase was to get across that people should shut down as soon as they feel unsafe – and actually do it.  

“You have to accept the consequences of any uncertainty and close down the plant when necessary. And we’ve stuck to that.” 

The next step was to create a risk-based long-term plan for surface maintenance at the plant. Such a programme already existed but was stepped up sharply as a direct consequence of the 2016 incident.  

By 2018, the surface maintenance programme at Mongstad was three times bigger than for the entire NCS, and Storsæt reports that it has been escalated even further – by a factor of about six-seven from before the incident. 

But an average of 300 insulation, scaffolding and surface treatment (ISS) personnel working every day on the maintenance programme since 2016 have yet to cover the whole plant.  

That reflects the sheer quantity of piping at Mongstad – actually over 2 000 kilometres or more than four times the distance between Bergen and Oslo by car.  

And just like the road network around Mongstad, not all these pipes are straight. They contain every kind of bend.  

This piping geometry has made the work challenging and time-consuming. That's why new technology for detecting weaknesses and corrosion has also been important.  

Tools 

“We’ve launched a dedicated technology programme to develop new detection tools,” reports. Storsæt. He says a solution called Open Vision, which allows the surface condition of pipes to be inspected without removing insulation, is currently being qualified. 

“When that’s in place, we’ll save time and resources and be able to check previously rehabilitated systems without having to strip off perfectly good insulation and paint.” 

He will soon have such data for the entire plant. Despite the extra commitment launched after the 2016 incident, about 10 per cent of the facility remains to be inspected. And with new technology shortly in place, the remainder is set to proceed much more quickly. 

Anfinsen emphasises the importance of maintenance management for onshore facilities. “The plant itself has no defined design life – that applies to the equipment .” 

One nonconformity identified in Havtil's investigation report concerned  incident response. Since no risk assessment was carried out before personnel entered the area, known weaknesses had not been addressed and the risk of removing insulation from pipes and inspecting them was underestimated. 

Not without friction 

Although the incident and the subsequent investigations triggered many improvement processes, Storsæt acknowledges that the process has not been friction-free. 

“The problems revealed by the incident can’t be solved overnight. This process has enjoyed many victories, but also setbacks, challenges and serious occurrences.” 

In his view, he now leads a maintenance programme and an organisation which are more robust and competent in dealing with setbacks and problems.

But he admits that an investigation can take it out of one. 

“The exposure is intensive. It’s demanding to be responsible and under scrutiny by the regulator and your own employer while still having to run day-to-day processes at the plant.” 

Audits 

Havtil has been closely monitoring developments since the 2016 incident. Audits are carried out at Mongstad two or three times a year, with at least one concentrated specifically on hydrocarbon leaks and major accidents.  

“Our attention is focused on scrutinising management systems and maintenance programmes and on examining the company's own follow-up,” says Anfinsen. 

“We conduct system audits, including verification of documentation and equipment to measure compliance with regulatory requirements. In our view, that’s the most sensible approach.” 

The same applies to the implementation of new technology. As a regulator,

Havtil does not recommend one technical solution in preference to another. 

“We observe that new technology is being developed and we follow up its implementation,” says Morten Langøy in Havtil's structural integrity discipline.  

“A lot is happening in technological terms, including the development of sensors for detection and moisture measurement in pipes. We monitor this work but don’t stipulate specific guidelines.  

“We stay at the system level. Responsibility for taking care of safety rests with the companies.” 

Tool 

Langøy headed Havtil's investigation of the 2016 Mongstad incident, and points out that such enquiries are an important tool for the authority – not least in looking more closely at causal chains. The aim is to contribute to learning lessons and preventing similar incidents recurring. 

“This investigation and subsequent follow-up have had a positive effect,” says Langøy. “A number of measures implemented since 2016 have improved safety at the plant.”  

Storsæt emphasises the importance of building mutual confidence over time.  

“Interaction with the regulators has been characterised by continuity,” he says. “Many people have occupied the same roles for a long time. In this way, we’ve built up the necessary trust. 

“The regulatory authorities have shown understanding that changes in such a big organisation don’t take immediate effect. That’s been important.” 

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