Shale gas firms should set a minimum distance of 600 metres between their fracking process and water aquifers, according to new research released today which suggests this would be both “safe” and “prudent”.
Researchers from Durham, Cardiff and Norway’s University of Tromsø looked at thousands of natural and induced fractures from the US, Europe and Africa. Of the thousands artificially induced, none were found to exceed 600 metres, with the vast majority being much less than 250 metres in vertical extent.
The fracking or hydraulic fracturing process is where gas firms pump a mixture of highly pressurised water, sand and chemicals underground to force open tight shale rock, letting the gas flow out more freely.
Health concerns have been raised in some quarters with environmentalists worried the gas released or the fracking fluid could contaminate local water aquifers.
The new findings could potentially provide an answer to these concerns, as they show the chances of rogue fractures due to shale gas fracking going beyond 600m is a fraction of 1%.
Professor Richard Davies, Director of Durham Energy Institute at Durham University said: “Based on our observations, we believe that it may be prudent to adopt a minimum vertical separation distance for stimulated fracturing in shale reservoirs.
“Such a distance should be set by regulators; our study shows that for new exploration areas where there is no existing data, it should be significantly in excess of 0.6 km.”
He said setting a “maximum vertical distance” to frack would be “important” for the “safe” exploitation of unconventional hydrocarbons such as shale gas and oil.
Last week, a report for the Government gave the go ahead for fracking in the UK.