Environmentalists have dubbed the Elgin oil field in the North Sea as “the well from Hell” and said it will be hard to shut off.

The Elgin and the neighbouring Franklin field lie in a complex geological structure almost three and a half miles below the seabed.
They exercise around four times the pressure of an average North Sea oil field with temperatures more than double. Meanwhile the dangerous and corrosive gases, hydrogen sulphide and carbon dioxide are contained in the reservoir mix.

These factors creating profound difficulties for those seeking a solution.

Total’s initial response yesterday was to talk of three options. It could create a relief well as BP did with the Deepwater Horizon disaster two years ago off the Gulf Mexico which led to the worst spill in U.S. history.

Another possible plan would be to carry out a “dynamic kill” which involves pumping heavy “chemical mud” into the well to suppress the flow of gas, preventing it rising into the atmosphere.

There was also the chance that the gas escape could exhaust itself naturally.

David Hainsworth, health, safety and environment manager for Total E&P UK said: “I would say the best case scenario is that the gas is not very productive from this area and that it dies off over the coming days and weeks.”

But Frederic Hauge, head of Bellona, a Norwegian group that closely monitors the oil industry gas could be set ablaze enabling the rig to come close enough to drill the release well. But he said: “But this will still last for months before this situation can be solved.”

The reservoir lies 6,000 metres, or nearly four miles, beneath the seabed and is a high-pressure, high-temperature reservoir, he said, making shutting off the flow of gas bubbling to the surface harder.
“The pressure in the reservoir is 600-1,100 bar which is higher than at Deepwater Horizon’s, which was a little over 800 bar.”

Temperatures in the Elgin reservoir could reach 200C. Mr Hauge said: “We don’t know how much gas there is again in the reservoir and there is a high levels of carbon dioxide and hydrogen sulphide, which makes it extra corrosive.”

It is estimated that as much as 10% of the UK’s gas is produced by the Elgin-Franklin field.

Alex Kemp Schlumberger Professor of Petroleum Economics at Aberdeen University told the Herald that would present a problem for the time being.

He added: “There have been gas leaks before but they have been readily contained and not a big one which has caused so much difficulty.”

“Elgin/Franklin is a significant producer but this has come at a fortunate time. With the warm weather and spring, people will be turning down their central heating. Demand will be going down. I would think that suppliers of gas who have relied on Elgin would be able to replace it without too much difficulty. But come the winter it would be a very different story.”

Vicky Wyatt, of Greenpeace, said the gas leak was a reminder of the dangers that drilling for oil and gas pose to the lives of those working on rigs, and the huge damage to the environment.

She said: “This leak also shows how reckless Chancellor George Osborne was to hand over billions of pounds of taxpayers’ money to the oil and gas industry just last week to subsidise deep water drilling to the west of Shetland.”