Original URL: http://www.theregister.co.uk/2012/04/19/shale_gas_yesno/
Shale gas fracking ruled safe, but must stop at drop of a hat
Boffins' findings at odds with Dept of Climate Change
Is shale exploration in the UK on stop or go? On Monday the Department for Energy and Climate Change released a geological report into the impact of hydraulic fracturing, a key technique in releasing gas from shale rock deep beneath the Earth's surface. But, as befits the department with the schizophrenic identity, its findings are ambiguous.
On the go side, the three geologists conclude that fracking is safe, that there is only a “very small” risk of damage from fracking-induced quakes, and shale exploration will not cause rumbles greater than those we already experience from coal mining, at about 3.0 on the Richter magnitude scale of seismic activity. They add that this was due to the unusual nature of the site, and that “there is a very low probability” of quakes at other locations.
The potential for upward leaks is also low, thanks to the thousands of feet of impermeable rock between the shale and the surface.
They also explain that slightly more conservative drilling techniques – such as lowering the volume of liquid going down – would mitigate the risk. That’s good news for the gas industry, and the UK economy, which like the US could enjoy a manufacturing revival powered by cheap energy.
On the stop side, the department's bureaucrats have added a recommendation that any seismic activity over 0.5 on the scale that may be related to fracking should cause the fracking to stop. That’s very bad news for the gas industry and the UK economy
Why? The seismic scale is logarithmic, and 0.5 is equivalent to 3oz (85g) of TNT – or one-third of the energy released by a hand grenade - being detonated underground. The British Geological Survey doesn’t record earthquakes below 2.0M, the equivalent of 1 imperial ton of TNT, considered to be the smallest quake people can feel.
Quakes below 3.5 on the scale are “generally not felt but recorded”. Exploratory drilling 9,000ft down in the Bowland Basin in Lancashire by consortium Cuadrilla caused two quakes, of magnitude 2.3 and 1.5, prompting the company to halt the operation as a precaution.
The geology experts say: “An event of this size [2.3] at an expected depth of 2-3km is unlikely to cause structural damage.” That’s fairly clearly cut, then. So why do DECC staff recommend magnitude 0.5? They don’t say.
By recommending a threshold so low, it is hard to see how any continuous exploration can take place at all. Cuadrilla says it isn’t worried – but in its response it doesn’t mention the 0.5-magnitude stop condition. This is just a recommendation, however – a consultation runs until 25 May.
The analysis [PDF, 1MB] was carried out by Dr Brian Baptie, head of seismology at the British Geological Survey; Professor Peter Styles of Keele University; and independent consultant Dr Christopher Green, GFRAC.
The Independent newspaper wants all shale gas exploration halted, to save the planet.
“A new age of shale gas holds the risk that the decarbonisation of the UK energy system, essential if we are to meet our demanding climate change targets, will be pushed back and back,” the paper declares in an editorial. “Mass use of shale gas would make these targets unattainable.”
But two recent economic studies prove the opposite. The UK and Europe could meet their own carbon dioxide reduction targets by replacing dirty coal with cleaner gas and nuclear energy capacity.
So where does DECC sit? Well, the 'E' part of DECC serves the wider UK economy and wants cheap, safe, reliable energy. The 'CC' part of DECC serves Gaia, the Earth Goddess, and wants renewable energy even if the economy takes a hit. It appears the CC is still overruling the E. ®