Meet the Frackers - Part 1

“Meet the frackers” has become a popular name for news articles, TV documentaries and campaign groups linked to fracking. Over the next few weeks I am focus on fracking for my blog posts. Firstly lets introduce the process of hydraulic fracturing for oil and gas and address two of the key issues the process has raised.

Hydraulic fracking is a process where fluid is pumped into rock at high pressure which causes the rock to fracture. This creates more space within the rock and allows oil and gas to percolate through the formation therefore it can be pumped to the surface and extracted. It has been used in the USA, extracting gas from areas such as the Marcellus Shale, for the last decade and has recently been given the green light by the UK government.

Video: BBC Horizon programme "Fracking: The New Energy Rush" 

Issue One: Does fracking cause earthquakes?

The honest answer: yes it can. The more the more important question is do these earthquakes matter and can they be avoided? Recorded earthquakes induced by hydraulic fracturing have a magnitude in the range of 1.0 – 3.8. This causes comparable ground shaking to a large articulated lorry driving past your house. Much higher magnitude earthquakes have been recorded from the use of controlled explosions in mining, up to 5.1, and from reservoir impoundment where the weight of the water causes ground fracturing, up to 7.9. (Davis et at 2013). So the earthquake damage cause by earthquakes induced by fracking doesn't even come close to other anthropogenic causes. 

Even if the earthquakes are small, it is important that oil and gas companies do all they can to avoid it in the first place. This can be achieved by improved research and method in the operations. A review of fracking in the UK was carried out which addressed the earthquakes causes in Blackpool (Royal Society and Royal Academy of Engineers 2012). They recommended that better fault plane analysis could help minimise risk of earthquakes by avoiding injecting fluid directly into fault planes. Overall they gave fracking the go ahead in the UK. 

Issue Two: will fracking contaminate groundwater?

 Image courtesy of John Cole Cartoons (The Times Tribune, Pennsylvania) 

Water contamination has been a huge issue for some US fracking operations. Using geochemical isotropic tracers at a fracking site in Pennsylvania, it was shown that increased levels of methane, chlorine and potassium in groundwater are “related to stray gas contamination directly linked to shale gas operations”. (Darrah et al 2012, Procedia of Earth and Planetary Science). This maybe a case where improved technology and processes can prevent this occurring again however for some communities fracking has already had a severe impact on quality of life.