Across Europe, between 1980 and 2006, approximately 96 incidents reported in the MARS database relating to major accident potential loss of containment are estimated to be due to ageing plant. This represents 28% of all reported major accident loss of containment events in the MARS database and equates to an overall loss of 11 lives, 183 injuries and over €170Million of economic loss. The study of the MARS database has determined that approximately 60% of incidents are related to technical integrity and of those 50% have ageing as a contributory factor, it is therefore concluded that plant ageing is a significant safety issue and one that is likely to increase with time as assets continue to age further.
The 2002 NACE cost of corrosion study estimated the direct cost to the UK economy to be 3.1% of GDP, and for the oil and gas industry alone corrosion was estimated to cost $1.4 Billion annually.
The offshore hydrocarbon release figures indicate that for 2011/12 there were 425 reported dangerous occurrences, seven fewer than last year – with equipment failure accounting for 30 percent, hydrocarbon releases 29.9 percent, well-related incidents made up 10.1 percent and fire offshore 6.8 percent.
The harsh operating environment of the North Sea is a significant added component to the integrity risks faced by onshore hazardous plant and equipment. Superimposed upon the hazards connected with the produced hydrocarbons is the corrosivity associated with the marine environment and also the considerable loadings generated by wind and wave. When combined together these dangers create a major accident hazard risk which needs to be effectively managed throughout the entire life cycle of production and non-production platforms in the North Sea. Where these risks are managed ineffectively hydrocarbon leaks can occur, structural integrity may be compromised and in the extreme case uncontrolled hydrocarbon releases result and assets may be lost resulting in loss of life.
Approximately 50% of the fixed platforms on the UKCS have exceeded their original 25 year design life, and this proportion is steadily increasing with time. Technological advances, improved accessibility to “stranded” oil and gas deposits, and the higher price of oil and gas have created economically advantageous conditions in which it is profitable for offshore assets to continue producing for longer than initially anticipated, or which act as hubs for other producing facilities.
Ageing is not simply about the physical age of an asset, the risks associated with ageing start when the asset enters the sea. The management of equipment begins with an awareness that ageing is not about how old the equipment is, but is about what is known about its condition, and the factors that influence the onset, evolution and mitigation of its degradation. Once the symptoms of ageing are understood, and detected from inspection, a decision can be made how to proceed. The options can include putting together a case to justify continued service, re-rating, repair, or scrapping the equipment.
Ageing is not just about platform structures, pipework, and pressure vessels; it also includes control and instrumentation, software, staff demographics, skills, training and competencies.