Unconventional gas exploitation
My name is Greg, I work for a Scottish gas company and I am a founding member of the Utilities Scotland group. You might think those of us who work in the industry would welcome the Chancellor’s ‘dash for gas’. However, I share many of the concerns that have been highlighted in the weekend media and elsewhere. In particular concerns over the exploitation of “unconventional gas” – shale gas, coalbed methane and other underground gases that are trapped in deep rock formations.
The gas is in tiny holes scattered through large volumes of rock, rather than large caverns like traditional gas. This makes getting substantial amounts out and up to the surface difficult, although with new technologies potentially viable. The different ways of achieving this include:
- Fracking, hydraulic or ballistic: This frees the gas by deliberately fracturing the rock by drilling down and then pumping in high-pressure liquids, or even detonating explosive charges. Fracking can be used to extract the gas from shale, a type of rock, or to free “tight gas” held in deeper, denser rock formations. It can also be used to help mine the methane that inhabits coal seams.
- Tapping “coalbed methane”: This involves drilling into and along the seams, and then pumping out and disposing of large quantities of water, a process known as dewatering. The removal of water may be enough to stimulate the flow of gas, though sometimes fracking may also be necessary.
These methods are certainly controversial. Drilling in Lancashire was suspended when it appeared to cause two small earthquakes in Blackpool, although the Energy Secretary may soon lift this moratorium. Andrew Rawnsley’s piece in the Observer gives a sceptical overview of safety and viability, he concludes:
“To take so many risks with our nation’s future on the basis of such a flimsy dream is – how can I put this politely? – fracking crazy.”
The Observer also reports that the EU may regulate the industry. Jo Leinen MEP, a member of the European Parliament’s Environment Committee, said the UK government could not be confident it understood the scale of health and environmental consequences.
There are varied estimates of the UK’s unconventional gas reserves. The British Geological Survey estimates 150 billion cubic metres, equivalent to about 18 months’ usage at current rates. There could be significant reserves in Scotland, though it’s unclear how much is recoverable.
Dart Energy wants to sink 14 wells in the Central Belt as part of a £300 million deal to supply gas to Scottish and Southern Energy. Scotland on Sunday and the Sunday Herald ran stories over safety fears raised by rail engineers who have warned explosions could be caused by uncontrolled emissions of the flammable gas at two sites beside the Larbert to Stirling line. Network Rail have lodged a formal objection based on these concerns. The local Shieldhill and California Community Council, near Falkirk, are not surprisingly concerned, they said: “This is a concern. Wherever there is methane there is a concern about fugitive emissions. The problem is we’re ignorant in a sense about all this. This is the first commercial production of methane in the UK.”
The debate over the ‘dash for gas’ clearly has some way to go – at least as far as unconventional reserves are concerned.
- Posted in: Gas