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Wednesday 2 March 2011

Shale Sale: Another Inconvenient Truth

The sudden interest in shale gas, and the blatant hyping of its cost and environmental impact, by Maily Telegraph blogger James “saviour of Western civilisation” Delingpole was something that at first I found perplexing. However, the mention by Andrew Orlowski in his latest pro-shale gas piece for The Register of the documentary film Gasland did the trick.

Orlowski – who mis-spells the title of the documentary Gaslands – calls it “agitprop”. But is it? The film, made by Josh Fox, investigates the way in which natural gas is extracted from shale beds by the process called Hydraulic Fracturing, or fracking. Some of the facts unearthed by Fox are not in question.

To exploit shale beds, a well is driven down vertically and then horizontally. The depth of the well is typically around 8,000 feet. Then water – a typical amount for each “frack” is three million gallons – is pumped in, together with a mix of chemicals. These may include benzene, ethanol, ammonium salt, and various acids. The pressure at which the mixture is pumped in causes the shale beds to fracture.

The fissures opened up in the rock enable gas to be released, but that gas does not come out as gas: it has to be separated out from waste water on the surface. No more than half the water pumped in to a well is recovered. The potential for pollution from the remainder of the water, plus the risk of it getting into ground water, is obvious.

Once a well has been “fracked”, that is not the end of the matter: a well may be “fracked” several times, and each occasion has the potential to do more damage. The technology, despite Orlowski’s suggestion of current novelty, dates back to the 1940s, with the first commercial application in 1949 by a company whose name may be familiar: Halliburton.

There are moves in the USA to get producers to reveal the mix of chemicals – currently up to 200 tonnes per “frack” – that they add to the water as it is pumped into the well. And there is also pressure to end the exemption for hydraulic fracture wells from the Safe Drinking Water Act. This last is known as the “Halliburton loophole”.

So there you have it: gas produced by hydraulic fracture, as it is from shale beds, does not look quite as “cheap” or “clean” as Orlowski asserts. Small wonder that the idea is not yet being nodded through by Parliament.

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