Dani Garavelli: ‘Wells from hell are now operating on the limits of what’s an acceptable risk’
With the threat of an explosion still hanging over the Elgin platform, Dani Garavelli discovers growing concern over a hi-tech industry pushing the boundaries of what is achievable
THOUGHTS of Piper Alpha, the North Sea’s biggest ever disaster, must have preyed on the minds of the workers on Total’s Elgin platform as they were told to lift their passports and grab bags and head for the helicopters which would take them to safety.
As fears about the gas leak at the “well from hell”, 240km off the coast of Aberdeen, grew last Sunday, the men understood only too clearly the destruction that would be caused if the vapour cloud forming on the water around the platform ignited.
Thankfully, it was textbook evacuation; by 3.30am the following day, all the 238 men on the Processing Utilities and Quarters platform and the nearby Rowan Viking Drill were back onshore, leaving the Elgin a ghost rig sitting in a bubbling pool of gas condensate (a light hydrocarbon liquid from gas). But the power-down didn’t go without a hitch. In the rush to get away, a flare meant to burn off excess gas was left on, meaning that, although all electrical equipment had been switched off, there was still a real danger of an explosion.
The news, which filtered out last week, sent shockwaves rippling through the industry. Though clearly the immediate threat to life had been removed, the spectre of a blast on the scale of Piper Alpha, which killed 167 men in 1989, still loomed large.
A two-mile exclusion zone for ships and a three-mile exclusion zone for planes was set up and fire ships were drafted in near the scene. As panic mounted, all but a handful of workers were removed from Elgin’s sister wellhead platform, the Franklin (which is connected to Elgin by a sub-sea pipe) and from Shell’s nearby platform, the Shearwater. Insisting this wasn’t enough, Unite union regional industrial officer Willie Wallace called for every worker operating within a five-mile radius to be evacuated. As the oil and gas industry’s safety record was again being challenged, Total’s share prices fell and oil and gas prices rose.
Seven days on from the start of the incident, the sense of panic has diminished. Total says it believes the leak is coming from a disused well in a rock formation 4,000 metres below the seabed, not from a well that is currently producing gas. It is free of toxic hydrogen sulphide and consists mainly of methane, which disperses more easily. The fact it is gas rather than heavy crude oil which is spewing out at an estimated rate of 2kg a second means there was never really a threat of an ecological disaster on the scale of the Deepwater Horizon in the Gulf of Mexico, and the lack of hydrogen sulphide further reduces the risk to sealife in the surrounding area. Total says Elgin’s other four wells appear unaffected and that the procedure to shut down the valves has been successful.
Crucially, it was confirmed yesterday that the flare – which is around 100 metres from the leak – had “extinguished itself”. Fortunately, wind direction in the past seven days had blown the gas vapour cloud in the opposite direction, away from the flame.
Nonetheless, the gas is still leaking, and although Total have drafted in dozens of global experts there is still confusion and how and when this crisis is going to end.
“It’s not anywhere near as bad as it could be, but it’s not good,” says Dr Simon Boxall, oceanographer and marine pollution expert at Southampton University. “The main problem is there are four other well-heads going into that same rig. Even if the valves are shut, it’s like having a tap. It may be off, but if you pull the sink from the wall, you get a lot of pipework, and if the pipework fractures, then there’s water everywhere.”
Those keeping a close eye on the crisis say it is only by good fortune that, with the flare no longer providing a naked flame near the gas leak, the threat of an explosion appears to have been averted. Jake Molloy, of the Offshore Industry Liasion Committee (OILC) union. “I have spent 17 years offshore and I know the wind direction can change in a heartbeat,” he said. “You can literally see the flare spin round on the flare stack when that happens.
Credit Agency Fitch said the cost of the “utter devastation” caused by an explosion could have been as high as $10 billion not including environmental fines.
Total is currently working on two possible options for tackling the problem. If the gas leaks stops of its own accord, workers could board the platform and perform a “kill” operation, pumping heavy mud into the affected well to reduce pressure and stop any potential for further gas escaping.
Or they could drill one or two relief wells, which would intersect with the leak then pump the heavy mud down through them – an operation that could cost the company up to £3bn and take up to six months to carry out.
In the meantime, the company has questions to answer. Why was the flare (used to burn off the dregs of the gas forced up the working wells) not extinguished before the platform was abandoned? Did Total, as the RMT claims, repeatedly tell workers there was no risk from the time the pressure problems began right up until a few hours before the leak was discovered? And, since experts have repeatedly warned of increasing instability as fields such as Elgin/Franklin – which extract gas at higher temperatures and greater pressures than ever before – are depleted, could more have been done to prevent it?
There are broader questions for the industry too. With North Sea resources dwindling, companies are drilling in ever more inaccessible areas. Does this leak suggest oil companies are now operating at the limits of their technological capabilities? Does the continued dash for gas, driven by a UK government which wants to be less reliant on exports from other countries, mean unacceptable risks are being taken?
The British government has been keen to encourage companies to drill in high-temperature, high-pressure fields, and is currently considering extended tax allowances as an incentive to companies to get involved.
When the Elgin/Franklin field was being developed, Total described it as “an unprecedented technical challenge” because of temperatures of up to 190C and reservoir pressures up to four times higher than the North Sea average.
But there are dangers inherent in operating in such extreme conditions. In 2005, a report for the Health and Safety Executive warned that, despite industry successes in overcoming the technical challenges, “there remains a general concern that not all high- pressure/high-temperature hazards have been identified yet.”
Total is well aware of these dangers. According to the Wall Street Journal, last year a report written by Jean-Louis Bergerot, a manager in Total’s drilling division for the Society of Petroleum Engineers, suggested the risks were growing.
“In fields such as Elgin/Franklin, wells are exposed to multiple threats resulting from the large amount of depletion,” he wrote. “As gas is pumped out of the reservoir, its pressure drops relative to the surrounding rock, unleashing powerful stresses. The steel casing that lines a well can be buckled or deformed by movements in the rock. Eventually, the liner may become sheared off completely.”
In his report, Bergerot says faults in the rock could reactivate with little warning and allow oil and gas to move into unexpected places within the rock formation.
The recent problems on the Elgin platform began four weeks ago when the company noticed pressure changes in the disused well. Attempts to plug it permanently failed when the company lost control of the pressure, and flammable gas and condensate started to leak. Total has said the gas is probably entering the well through a leak in its casing.
David Hainsworth, health, safety and environment manager at Total UK, said: “What we’ve been doing over the past two or three years is plugging and abandoning those old wells [which have had their casings compromised].” The well that is now leaking was shut down more than 12 months ago. “There is nothing to suggest this job was done inadequately prior to the leak,” Hainsworth said.
The number of fields with challenges similar to those faced in Elgin/Franklin is growing fast. In 2009, the Department of Energy and Climate Change released figures suggesting 12-15 per cent of the total number of UK offshore oil and gas discoveries and prospects were of the high-pressure, high-temperature type.
“Many people talk about peak oil. I think there are a lot of hydrocarbons; that’s not the problem – or rather that is the problem, depending on how you look at it,” said Frederic Hauge, president of environmental group Bellona. “I think easy peak oil is over. Companies are having to go deeper, hotter, and higher pressure and move to more dangerous areas – and the costs of this could be huge.
“I think this incident will lead to a discussion of how long you can empty the reservoirs. It seems these complicated wells are more problematic than the oil industry had expected.”
After the immediate danger at Total Elgin has been averted, attention is likely to shift towards tightening industry-wide guidelines.
The EU’s spokeswoman for energy issues, Marlene Holzner said it would still be possible to tweak a proposal for stricter safety rules on offshore drilling, taking into account lessons learned from Total Elgin.
In the meantime, the Elgin field which, together with Franklin produces 280,000 barrels of oil equivalent, 175,000 barrels of condensate and 15.5 million cubic metres of gas a day, is expected to be shut for most of the year.
“This incident underlines the risks of the offshore oil industry and reinforces our concerns about the even riskier deepwater drilling which has just started at the North Uist well and plans for Arctic drilling,” Dr Richard Dixon, director of the WWF Scotland, said.
Hauge agrees. “What we have seen from wells from hell like this is that companies are now operating on the limits, perhaps over the limits, of what’s an acceptable risk,” he said. «
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Monday 20 May 2013
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