Fire safety challenge for the offshore sector

Louise Smyth

Howard Johnson explores how the offshore sector can best tackle the fire safety challenges it currently faces

2018 marks 30 years since one of the worst industry disasters in history, the Piper Alpha tragedy. The disaster, which killed 167 rig workers is regarded as one of the deadliest ever oil rig accidents.

As a result, in his report on the tragedy, Lord Cullen made more than 100 recommendations about how safety should be improved in the North Sea. Key to this was moving regulatory control for the offshore industry into the hands of the Health and Safety Executive.

There are many challenges facing the oil and gas sector, including the growing number of ageing assets, with many installations now operating beyond their design life. Drilling is taking place in ever deeper water and in more hostile and hazardous environments. More than ever operators need to improve the safety and integrity of people and plant, while ensuring a cost-effective and environmentally friendly delivery.

Over the past few years, through the development of innovative fire safety systems and improved testing and maintenance procedures, Blaze has met the budgetary constraints of operators without compromising on safety and has reduced the environmental impact of regular testing and maintenance activities
on assets.

Variety of solutions

The company’s systems range from gas suppression to fire-fighting foam and firewater deluge and it has been developing them to have a lower carbon footprint. For gas suppression, the firm avoids discharging systems to check enclosure leakage rates by undertaking integrity testing to ensure that fire-extinguishing concentrations will be held for the required time. With global warming being a key environmental issue now and for the future, Blaze promotes the use of inert gas systems such as IG541 and IG55, which are composed of naturally occurring gases which make up the atmosphere: nitrogen, argon and CO2 – the latter being the by-product of other industrial processes. The company also advocates the use of chemical suppression agents such as Novec 1230, which has a global warming potential of one and an atmospheric lifetime of only a few days.

In 2015, the US Environmental Protection Agency founded the PFOA stewardship programme for firefighting foam manufacturers worldwide to commit to the withdrawal of products containing fluorosurfactants having a carbon chain length greater than C6.

This change has a significant impact on firefighting foam users. Biodegradable synthetic-based fluorine-free products are now widely used. However, foam agents that do not contain fluorinated surfactants usually contain higher concentrations of hydrocarbon surfactants and solvents to compensate for the lack of film formation. This results in a more acute aquatic toxicity than the agents they replaced.

There are alternatives to discharging firefighting foam and when testing of foam producing equipment is required, Blaze recommends the use of test foams that do not have detrimental environmental impact.

The issue of corrosion

Saltwater corrosion to oil rigs reduces the condition of assets considerably and this poses a safety and financial threat to operators. Currently in an offshore environment, deluge systems are tested by passing seawater through the system, which is sprayed over the equipment on the oil rig. This seawater causes accelerated corrosion of the equipment and the deluge system itself. Wet testing currently takes place anywhere between every six months to every five years, with older systems requiring more frequent testing than newer systems. This increased wet deluge testing exacerbates corrosion within the pipework, resulting in possible unplanned shut-downs to rectify the resulting damage.

Frequent wet testing also increases the risk of the drains’ caissons becoming overwhelmed with the water volume, resulting in the likelihood of oil fractions being carried into the water outlet, causing water sheening downstream of the asset during testing. This has an obvious impact on the environment and marine-life.

Wet-testing cannot be completely eliminated, but the impact versus the benefit must be fully considered. Dousing the topsides plant with seawater is not desirable as this exasperates corrosion and plant failure. In response, Blaze has developed test regimes ranging from smoke testing, dry testing of equipment, borescope inspection and wall thickness verification. This is offered as part of a maintenance programme that also includes pipe cleaning by environmentally friendly chemicals or high-pressure waterspray and that will reduce the need to undertake frequent wet-testing.

Vapo-Flo is a non-toxic smoke generating system that uses an oil-based vapour instead of water to test the effectiveness of deluge systems. It works by blowing smoke through the pipework via the deluge valve test line. Blockages can be visually detected by a reduction in smoke exiting the nozzles, allowing for further investigation and remedial work. This can be carried out using a boroscope to check for blockages or poor pipe condition. It is also possible to carry this out without shutting down or interrupting ongoing work in the area, reducing the possible loss of valuable production hours.  

Data-based approach

Many fire protection systems and performance standards contain requirements for periodic inspection, testing and maintenance (ITM). These are generally based upon historical requirements and not on any field data or on observed deficiencies. The National Fire Protection Association (NFPA) has developed new documents, such as NFPA 4 on Integrated Testing of Fire Protection Systems, recognising the need for a more data-based approach to ITM frequencies.

Accepted by verification bodies, Blaze uses this approach for delivering and optimising inspection, testing and maintenance routines, reducing the impact on plant and sub-systems.

The company continues to develop and improve its solutions to ensure that it is not only meeting safety standards but surpassing them.

Howard Johnson is Managing Director of Blaze Manufacturing Solutions.

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