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Growing Gas Cloud Forces Evacuation of Oil Rig in North Sea
French-owned platform is abandoned with no answers yet on how to avert further calamity
An oil and gas platform owned by French oil giant Total has been evacuated and an 'exclusion zone' has been set up around it, as a cloud of natural gas hovers over the site and a six-mile long 'sheen' has formed in the ocean around the rig.
Ships have been ordered by Maritime and Coastguard Agency in the UK to stay at least two miles from the Elgin PUQ platform, which sits about 150 miles off Aberdeen on Scotland's east coast, and aircraft must stay at least three miles away.
Technical teams from the oil company were investigating the cause of the gas leak but declined to give further details, according to a Total spokesman today. The company contends that although the situation is 'stable' though they admit they do not yet know the source of the leak.
Environmentalists have warned about the inherent risks of drilling in the North Sea, and Bellona, a Norwegian environmental NGO, has been monitoring this well closely.“This is a gas blowout that is out of control and is going to be so for a long time," Bellona President Frederic Hauge said. “The information we have right now indicates that it will be very challenging to prevent a blowout. This is a critical situation that is out of control.”
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Jake Molloy, of the RMT union which represents offshore workers, was asked if the incident was the most serious in the North Sea since the 1988 Piper Alpha oil platform tragedy which saw 167 men die.
He told BBC Scotland: "Fortunately we have dealt with the human side of it, but the potential exists for catastrophic devastation.
"If it somehow finds an ignition source we could be looking at complete destruction." [...]
Dr Simon Boxall, an oceanographer at Southampton University, told BBC Scotland that this was not a deepwater drilling rig and platform but it was unusual in that they were drilling down 5km (3.1 miles) into the sea bed.
He said: "It is a very deep well. The gas they are bringing up is what we call sour gas.
"That gas has a high proportion of hydrogen sulfide and carbon dioxide and that makes it very flammable and quite poisonous.
"So the big problem they have got is dealing with a very combustible gas - unlike Deepwater Horizon where we were dealing with crude oil which ironically is very difficult to light sometimes."
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Total Gas Leak in North Sea Out of Control for Foreseeable Future
As the news started to pour into the Bellona offices on Monday night, the information became more and more alarming.
“The information we have right now indicates that it will be very challenging to prevent a blowout. This is a critical situation that is out of control,” Hauge said.
Jake Molloy, the head of the section of the UK union that represents offshore oil and gas workers, agreed telling Reuters that A separate relief well may need to be drilled to ease pressure and allow emergency teams to regain entry to the rig and try to fix the problem.
"The well in question had caused Total some problems for some considerable time ... a decision was taken weeks ago to try to kill the well, but then an incident began to develop over the weekend," said Malloy.
"Engineers have told me that it is almost certain that gas is leaking directly from the reservoir through the pipe casing," he said – something Hauge had pointed out might be the case early Monday morning.
So far, three oil platforms – the Elgin, Shell’s Shearwater and nearby Rowan Viking drilling rig have evacuated a total of 323 workers – 238 from Elgin alone.
The Elgin/Franklin reservoirs are located off the coast of Aberdeen, Scotland in an area of high petroleum activity. The fields are linked. The area contains a large field with wells up to 6000 meters deep and that hold extreme pressure and temperature.
During the drilling of Elgin/Franklin in 2003, world records for pressure and temperature were broken as engineers found reservoir pressures between 600 and 1100 bar and temperatures reaching 200 degree Celsius. By comparison, the Deepwater Horizon blowout occurred at 896 bar. The field on which the platform is located was discovered in 1991.
Bellona has learned that there have been incidents at the well that have veered dangerously close to accidents, including a serious incident in 2005. Other grave safety shortcomings have also been revealed in this field.
Total was, in fact, considering killing the well when the problems began over the weekend.
“The well in question had caused Total some problems for some considerable time [...] a decision was taken weeks ago to try to kill the well, but then an incident began to develop,” Malloy was quoted by the BBC as saying.
Elgin identified as a problem well
According to Hauge, the Elgin/Franklin is “the well from hell.”
The incident leading up to the bubbling disaster started early on Sunday morning at Elgin platform when workers discovered a well control problem.
They noted a blue sheen on the water’s surface and bubbles from boiling water beneath the platform. The leak was already so large Sunday by 12:15 that 219 non-critical personnel were evacuated to Aberdeen, leaving a skeleton crew of 19 aboard the platform.
Crews from Elgin, other platforms evacuated
Those left behind tried to gain control of the leak. Over 114 hours, they attempted to jam the well with drilling mud with no success. At 6:14 am, they abandoned their attempts and were evacuated, which raises the chances of a major blowout significantly.
After the evacuation, a no-fly zone of three nautical miles around the well was established. Coastguards said shipping was also being ordered to keep at least two nautical miles away.
During the evening on Monday the gas cloud is became so large that workers aboard Shell’s Shearwater platform 6 kilometers away reported they could smell it.
Shell also evacuated 52 of the 90 workers aboard Shearwater platform, leaving 38 onboard. Thirty three of these have now been evacuated to the nearby Noble Hans Deul platform
Petroleum company Total E & P United Kingdom (TEP United Kingdom) operates the Elgin/Franklin platform and Rowan Viking rig, which was connected to Elgin. Total E & P told Bellona that both the platform and the rig are intact and confirmed that all crew have been evacuated to the mainland.
Impossible to stop
In Bellona's analysis, the discharge at the Elgin field is going to be very difficult to stop. When the gas escapes it becomes impossible to get back on board the platform to deal with it. Gas in the water affects the buoyancy of possible rescue rigs, and the water is flammable. [...]
When gas and condensate coming from such great depths as great as 5000 meters at high pressures rise, they will expand exponentially on their way to the surface. Sand and debris will dig holes in metal near the bore hole. If the gas is moving outside of the well, it will dig further and further into the bore’s rise.
Problematic relief wells
Bellona believes that when a platform is evacuated, the only remaining measure to bring the situation under control is drilling a relief well – as was done at Deepwater Horizon.
But Bellona fears this may difficult if not impossible. Such a well must be drilled very deep depending on how deep the leak in the Elgin well is. To dig the relief well, workers must somehow drill in under the leak and put in a new plug. Doing this depends on using highly advanced platforms in a nearly surgical procedure that can take months.
High gas concentrations in the area along with the fact that gas is in the air as far as 6 kilometers away is telling as it shows how far from any platform a relief well must be drilled to avoid aerial gas pollution.
But with buoyancy and flammability issues to consider, any rig drilling a relief well would have to do it from a great distance. To get a rig any closer than 10 kilometers, said Hauge, rescue workers would have to set the gas in the sea on fire.
But if there are platforms available to drill from such distance and this deep, the question that remains is will they do it? This, thinks Bellona, will be very difficult to arrange. Platforms of this nature would first have to be released from their current contracts, which will take time as such highly specialized rigs are used for drilling other complex wells. Drilling for the relief well alone could then take as long as three months if not far longer.
So task number one at the moment, says Bellona, is to immediately secure a drilling platform that is capable of drilling the relief well. If such equipment is available, it must immediately be requisitioned.
If drilling a relief well is not possible, the only solution is the worst-case scenario of letting the reservoir blow out until all of its pressure is tamped down. As the quantity of gas in the reservoir is unknown, fears that large amounts remain are founded. This gas would then be released into the water and air for a long time to come.
The environmental consequences of this accident could be substantial. Having large amounts of hydrocarbons in water and on the surface is not desirable. It will not look like an oil spill, but the hydrocarbons released will have many of the same dramatic effects. Bacteria, for instance, ingest hydrocarbons and hence consume enormous amounts of oxygen in the water. Condensate blue sheen on the surface of the water will destroy the plumage of sea foul.
Should the situation develop to the point where all the gas from the reservoir is released, it will lead to major emissions of greenhouse gasses: When unburned natural gas enters the atmosphere, its detrimental effect on the atmosphere is 20 times worse than CO2.
Difficult choices ahead
The coming days will lead to difficult choices as Total struggles to bring the lead under control. If the worst case scenario does indeed occur, it must be considered whether setting fire to the spill is not the best course of action. This too will have environmental consequences, putting Total and the government between the devil and the deep blue sea.
The Elgin/Franklin accident bears similarities to the Deepwater Horizon blowout, the only real difference being that Elgin is pumping gas condensate and not crude oil into the sea. The Rowan Viking rig is a brand new platform launched in 2010 and considered – like the Deepwater Horizon rig – to be state of the art for the drilling industry.
Rough conditions in the North Sea
The drilling was taking place under difficult conditions, with extreme pressure, high temperatures and great depths of the reservoir. Drilling in such circumstances involves enormous gambles: In situations like this, there are no ready-made solutions for dealing with the worst-case scenario, as Deepwater Horizon showed.
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