Safer Than You Think
A Debate on Fracking
Hydraulic fracturing, or ‘fracking’, is a mining technology in which hydraulically pressurized liquid is used to crack rock, thereby allowing the recovery of hydrocarbons such as gas and oil. Almost no issue of our times has aroused as much heated debate as fracking, to the point where the real issues are almost overwhelmed by Hollywood films, lobbying groups and geopolitical arguments.
Safer Than You Think
By Dr Joe Cartwright
Too Risky by Far
By Dr Jeremy Leggett
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Safer Than You Think
By Dr Joe Cartwright
Fracking has already been used in more than two million boreholes; so it is hardly a new and unproven methodology. For instance, fracking is routinely used to enhance recovery of oil and gas from many conventional reservoirs of sandstone and shale. An example is in Europe’s largest onshore oil field in Dorset, Wytch Farm, nestled in the beautiful New Forest. The legitimate concerns relating to fracking are no greater than would apply to any industrial operation, and are addressed by the right regulatory framework. But there is huge public fear and even unrest in many countries and indeed, in the US itself, at the prospect of fracking coming to ‘our community.’
Hydraulic fracturing of a shale gas reservoir involves drilling into the reservoir and pumping fluid into it at sufficiently high pressure to overcome the natural tensile strength, plus the confining stress. There is nothing intrinsically dangerous about pumping fluid into the deep subsurface at high pressure, provided the well is monitored carefully throughout. The resulting minor ‘earthquakes’ are tiny, relative to destructive earthquakes,
‘The legitimate concerns are no greater than would apply to any industrial operation’
chemicals being incorporated with water and sand into the fracking fluid will eventually penetrate groundwater aquifers. This is a fear that rests on a failure to grasp the scale of frack-ing. A typical fracture is less than a centimetre across and no more than 200 to 300 metres tall. Because shale gas reservoirs are exploited at depths of only two to three kilometres below the surface, and groundwater aquifers are typically a few hundred metres beneath the surface, the likelihood of fractures propagating anywhere near the water supply is extremely small.
The greatest risk to groundwater comes instead from poor drilling methods, and particularly from poor quality cement lining of the borehole, which is a recognised problem for all drilling operations and for which regulations are already specifically designed. The chemicals used in fracking fluid also amount to about one per cent of the total pumped volume, and are strictly controlled in the US and UK. Methane leakage into the atmosphere is not well quantified at present, partly because of the paucity
of data on natural leakage of methane from the deep subsurface into shallow aquifers and to the surface; but this does need careful monitoring in the future.
Without a doubt, the greatest risk to communities where fracking operations would be undertaken comes not from pollution from drilling, or from induced seismicity, but from the vastly increased road traffic that would be required to supply the drill site. Only local communities can judge whether this disruption is justified by the privileges of living in a highly developed society, fuelled (at least for the time being) in large measure by oil and gas.
Dr Joe Cartwright (DPhil in rift systems, 1988) was appointed the Shell Professor of Earth Sciences at Oxford in 2012. He worked for Shell International as an exploration geophysicist, was at Imperial College as a Senior Lecturer until 1999, and was appointed Honorary Professor of the Institut Français du Petrole in 1998.
Too Risky by Far
By Dr Jeremy Leggett
I am opposed to fracking in the UK for five main reasons: economic risk, local environmental cost, global environmental cost, social cost and opportunity cost. All the evidence for what follows is in the log of events on my website, www.jeremyleggett.net.
First, the economic risk. The US ‘shale boom’ looks as though it will turn into a bubble. The oil and gas industry is losing cash by the tens of billions of dollars, because high drilling costs mean most companies are spending more than they are earning from fracked gas and oil. Wider US industry may have benefited from cheap gas in the short term; but production from all shale gas regions save the Marcellus has peaked already, and many of us watching the detail see little prospect of the gas industry delivering growing production far into the future.
Second, the local environmental cost. Once Dick Cheney freed fracking from scrutiny under the Safe Water Act (the so-called ‘Halliburton Loophole’), bad news about contamination and health impacts should have been predictable. It has been slow to emerge, in part because of widespread use of gagging orders by the industry as part of compensation payments for wrecked farms and impaired health. But now a regular drip of bad news has started and is
‘Fracked gas may well be worse than coal in greenhouse terms, over the full-life-cycle’
soon likely to snowball as ever more people realize the reality behind the industry’s insistence that all is well.
Third, the global environmental cost. Gas industry operations can leak methane, a potent greenhouse gas, from wellhead to hob. Early research findings by the rare university teams not cowed by oil-industry funding are very worrying when it comes to frack-ing. Fracked gas may well prove to be worse than coal, in greenhouse terms, over the full-life-cycle. And British shale basins are far more faulted than US shale basins.
Fourth, the social cost. It is likely that few British people as yet fully appreciate the industrial infrastructure, waste disposal challenges and lorry movements that are required for a typical US shale ‘sweet spot’, and what the social cost of that
would be if superimposed on rural Britain. Yet already local opposition is severe, even against single vertical unfracked test wells. Planning for the first such was recently rejected by a council in Sussex for the first time, with objectors ‘weeping with relief’ in the chamber on hearing the decision.
Many such objectors are conservative voters. The prime minister says he wants to deliver sufficient shale gas to drive down the gas price enough for manufacturing to return to the UK. He has little or no chance of getting that past his own voter base without committing political suicide, even if much gas proves extractable by fracking – which the British Geological Survey clearly has doubts about.
Fifth, the opportunity cost. There is a shovel-ready alternative over time that can be developed
surprisingly quickly: a power source that is infinite and easy to tap. Politically, the government’s own opinion polls show that solar is outstandingly the most popular energy technology with the British public, year after year, miles ahead of fracking – even now, so early in the game. The opportunity cost is that many leaders in the oil and gas industry, and their supporters in government, want actively to suppress this fast-growing global industry, with its fast-falling cost base – along with other clean-energy industries – so as to not put investors in gas off.
Dr Jeremy Leggett (DPhil in earth sciences, Wolfson, 1978), author of The Energy of Nations, is founder and chairman of Solarcentury and founder and chairman of SolarAid, a solar lighting charity set up with 5% of Solarcentury’s annual profits, itself parent to a social venture, SunnyMoney, that is the top-selling retailer of solar lights in Africa. He is an Entrepreneur of the Year at the New Energy Awards.
The feature on fracking was first published in Oxford Today, the official magazine of the University of Oxford, in October 2014, and is reproduced here with the permission of the Chancellor, Masters and Scholars of The University of Oxford.
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