Elgin gas leak caused by “unique” corrosion event
14 March 2013
Total’s Elgin platform in the North Sea has resumed production following last year’s leak, now known to have been caused by a combination of high pressure and corrosion. On March 9, Total said oil production from the Elgin and Franklin fields had restarted in the UK sector of the North Sea, almost a year after a large-scale gas and condensate leak halted all production from the Elgin platform.
The Health and Safety Executive (HSE) accepted Total’s safety case for resuming operations on March 6.
The leak, which started on March 25 last year, took seven weeks to plug and at the height of the incident, about 200,000 cubic metres of gas was escaping every day, but the level reduced when workers drilled a relief well.
Some underwater Elgin wells have been abandoned in the wake of the leak and the company is planning to drill in new fields in the region to increase its production levels.
The leak cost Total around £1.6m a day in relief operations and lost income, with accumulated losses of around £83m. The Elgin and Franklin fields, which started production in 2001, accounted for nearly 5% of UK output. The shutdown knocked 0.2% off the UK’s GDF in 2012.
At a London press conference in February, Total said the Elgin leak was caused by a "unique" interaction of rock compaction and pipe corrosion.
Patrice de Vivies, Chairman of Total Holdings UK, said compaction caused unusual pressures higher up which eventually broke pipework weakened by corrosion. That corrosion was caused by a chemical reaction between bromide in the drilling fluid used to complete the well and grease in the pipework.
De Vivies said: "It was a unique type of corrosion not linked to ageing. We haven't changed procedures elsewhere because it was unique to Elgin."
But he added: "We will be much more conservative in future in the pressures we can meet from the well." Elgin is already one of the world's most highly pressurised fields.
Total is working on a full report on the causes of the incident. The HSE's investigation into the incident is also ongoing.
Vallourec, which makes the pipes used at Elgin, also said the corrosion was unique and that the incident did not call into question the quality of the company’s pipes.
The field, in which Total has a 46% stake, will return to its pre-accident production level – 120,000 barrels of oil equivalent (boe) per day – in 2015 and is targeted to reach 130,000-140,000 boe per day in 2016, a higher level than had been forecast before the accident, Total said.
Production increases will be achieved by the development of two big projects: phase two of West Franklin and a revamp of Elgin, expected to be finalised in summer 2013.
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