Engineering news
A study by researchers at Durham University has concluded that hydraulic “fracking” operations to recover shale gas do not cause significant earthquakes.
The desk study, reviewed hundreds of thousands of hydraulic fracturing operations over a period of 83 years, found only three cases of seismic activity resulting from the activity and that it “was on such a small scale only geoscientists would be able to detect it”.
Furthermore, the study found that other industrial activity, such as mining, geothermal energy and reservoir water storage causes more and larger earth tremors. Earthquakes caused by mining can range from a magnitude of 1.6 to 5.6, reservoir-filling from 2.0 to 7.9 and waste disposal from 2.0 to 5.7.
Professor Richard Davies from Durham Energy Institute, said: “In almost all cases, the seismic events caused by hydraulic fracturing have been undetectable other than by geoscientists. It is also low compared to other manmade triggers.
“By comparison, fracking-related events release energy roughly equivalent to or even less than someone jumping off a ladder onto the floor.”
Of the three fracking-related quakes that could be felt, the largest ever, in the Horn River Basin in Canada in 2011 had a magnitude of only 3.8, at the lower end of the range that could be felt by people. The widely-reported quake at Preese Hall near Blackpool on April 1 last year had a magnitude of 2.3.
Davies added: “Hydraulic fracturing is not a significant mechanism for inducing felt earthquakes. It is extremely unlikely that any of us will ever be able to feel an earthquake caused by fracking. But theoretically, it cannot be ruled out completely; we cannot see every fault underground and therefore cannot completely discount the possibility of the process causing a small felt earthquake.”
The study also concluded that fracking has the potential to reactivate dormant faults and described the probable ways in which the pumping of fracking fluid underground could trigger this.
This most recent study by Durham Univesity, titled “Induced Seismicity and the Hydraulic Fracturing of Low Permeability Sedimentary Rocks”, follows research published last year by the same researcher group that reached similar conclusions.
Despite the apparent success of fracking in the US, many environmentalists remain opposed to the activity. Tax incentives announced by the government in the budget last month to encourage fracking were condemned by Greenpeace. Lawerence Carter, and energy campaigner from Greenpeace, said: “Everyone from the energy regulator Ofgem to BP to the Energy Secretary says UK fracking won’t bring down bills. George Osborne needs to stop playing Britain’s JR Ewing and instead back the shift to carbon free energy, which will create jobs and be cleaner, safer and cheaper over time.”