When recently-appointed Energy Minister John Hayes showed his lack of fracking knowledge last month this political huckster inadvertently highlighted a troubling fact: at Cuadrilla’s site in Balcombe, West Sussex, fractures could reach within 720 feet of the surface.
Hayes claimed a Durham’s study “categorically refuted” suggestions that fracking fluids could get into aquifers. This sort of convenient untruth is commonly touted by the fracking industry; Hayes’ mistake was to make it public. It was quickly picked up by anti-fracking campaigners and reported in the Daily Telegraph.
In fact, applying the minister’s study to Balcombe would mean that fractures could reach the surface – and even – theoretically – 400m further.
Cuadrilla’s Balcombe plans show the company intends to drill at 2667 feet (810m). Professor Richard Davies, who led Hayes’ study, held that a maximum fracture could be 1928 feet (584m), and that the safety limit should be around 4000 feet (1200m) – a maximum fracture, therefore, would bring frack fluid to within two football pitches of the surface – Davies’ safe fracking distance would be 400m above the surface.
In November 2011 Cuadrilla admitted that faults such as the one that caused earthquakes in Lancashire may extend 2000 ft upwards (see p50 of linked pdf). Were the company to hit a similar structure in Balcombe this would bring fluids and gas even closer to the surface than man-made fractures. The fault that caused the earthquakes in Lancashire remains unidentified, despite two studies. The report provides yet more evidence that fractures can extend close to the surface.
In a ‘shallow frack’ such as Balcombe, the risks of fluid and gas migration are high. In their submission to parliament last year, Cuadrilla claimed fracking takes place at 5000 feet below the surface (see 6.3.11). No mention was made of Balcombe, which is scheduled to be be fracked at nearly half that depth. Durham’s study undermines those who claim that Balcombe’s unique geology makes it exempt from comparisons with other frack sites. In fact every frack site is unique: the Durham study is important because it shows fracture lengths averaged across many different types of terrain.
Meanwhile John Hayes and his DECC officials need to study the science better – instead of listening to the vested interests whispering in their ears.