A new sense of urgency is emerging around ageing offshore infrastructure as facilities reach the end of their design lives and major incidents cost millions – in some cases billions, a group of integrity management experts heard during a Petronas seminar titled Managing Risk on Ageing Offshore Infrastructure.
"Major incidents are leading to loss of life, environmental damage and huge costs in damage and lost production," said guest presenter Tony Hall, CEO of mooring integrity leader Welaptega Marine. "If we don’t take care of these ageing offshore facilities, significant loss of assets is inevitable."
Hall, whose company is a world leader in risk-based integrity verification in the floating production sector, says moorings are an example of "safety critical systems" which are subject to immense environmental forces including waves, currents, abrasion and hurricanes.
When you consider age-related wear and degradation of materials, and add to that the problem of unpredictable damage due to impacts, mooring systems are vulnerable and at risk of failure.
"We have to know that these aging assets are still fit for purpose," said Hall told the group. "It’s a balance between safety, profitability and risk."
Hall said offshore oil and gas operators can no longer afford to neglect ageing offshore infrastructure because the costs and consequences are potentially catastrophic. Companies can realise huge savings through proactive integrity management that not only reduces risk but also extends the working life of older facilities for functions such as subsea tiebacks and gathering operations.
"Mooring failure is classified as a class one hazard, the highest ranking given by the UK health and safety executive," said Hall. "In most cases moorings are the primary and only station-keeping system."
High-profile mooring failures such as the Maersk Gryphon Alpha highlight the potential costs. During a storm in the North Sea in February 2011, four of ten mooring chains broke, putting the facility out of commission and resulting in estimated insured losses of between $900m and $1.5bn
In January 2012 the Premier Oil Banff FPSO broke its anchors in the North Sea causing damage to risers and putting the facility out of production. Insured losses are estimated at $300m.
Hall told the group that operators and contractors will realise savings through lifecycle inspection strategies which begin with a risk-based review of the mooring design and continue with inspections before installation of a mooring system and on a regular cycle post-installation.
Working in the oil and gas offshore inspection sector for the past 20 years, Mr Hall has witnessed the progress of age-related wear on mooring systems in floating production.
His company has developed imaging and measuring technologies such as high-definition 3D video and 3D modeling to inspect underwater components such as mooring chains and wire rope.
Hall praised companies like Petronas for organising the seminar and taking a lead in proactive integrity management of offshore assets. He also praised companies such as Woodside, Chevron, Marathon and Petrobras that have used lifecycle inspection approach to integrity monitoring.
Other guest speakers at the seminar included:
- Chuon-Szen Ong, Technical Director for BPP-Tech in London speaking on Subsea structures – fixed structures / umbilicals / risers
- Doug Hamer with NRG Well Services, who spoke on managing ageing wells – problems and interventions
- Dr. Gareth John of Intertek CAPCIS who spoke on corrosion/ageing of structures
- Ian Partridge of the Welding Institute speaking on structures / pipelines – ageing, monitoring, inspections, constraints
- James Miller of ACE Global Energy who spoke on national perspectives on ageing structures / corporate issues