Fracking 'Not Significant' in Causing Earth Tremors
New research has found that hydraulic fracturing (fracking) is "not significant" in causing earth tremors. Released Wednesday by the UK's Durham University, the results of a study of hundreds of thousands of fracking operations showed that the process only caused earth tremors that could be felt on the surface in three cases.
The research, titled Induced Seismicity and the Hydraulic Fracturing of Low Permeability Sedimentary Rocks, found that almost all of the resultant seismic activity was on such a small scale that only geoscientists would be able to detect it. It also discovered that the size and number of tremors is low compared to other manmade triggers such as mining, geothermal activity or reservoir water storage.
However, Durham University's report does establish beyond doubt that fracking has the potential to reactivate dormant faults and describes the probable ways in which the pumping of fracking fluid underground triggers this.
"We have examined not just fracking-related occurrences but all induced earthquakes - that is, those caused by human activity – since 1929. It is worth bearing in mind that other industrial-scale processes can trigger earthquakes including mining, filling reservoirs with water and the production of oil and gas. Even one of our cleanest forms of energy, geothermal, has some form in this respect," Professor Richard Davies, of the Durham Energy Institute, commented in a statement.
“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. 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.
"By comparison, most fracking-related events release a negligible amount of 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, even the largest ever, in the Horn River Basin in Canada in 2011 had a magnitude of only 3.8. That is at the lower end of the range that could be felt by people. The widely-reported quake at Preese Hall near Blackpool in 2011 had a magnitude of 2.3."
Cuadrilla Resources, which carried out the shale gas fracking activity that was believed to have caused the Preese Hall quake, has since installed seismic monitoring equipment at two of its sites near Blackpool in the northwest of England. The firm is hoping to recovere some of the 300 trillion cubic feet of natural gas that is believe to be held within shale rocks in the region's Bowland Basin. In a recent interview with Rigzone, Cuadrilla Development Director Mark Miller said that be believed Cuadrilla could be producing commercial gas from the basin before 2016.
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