Fracking remains a highly contentious issue among environmental campaigners but is a complex engineering process for extracting shale gas
East Lancashire became the latest area in England to be earmarked for fracking this week after energy firm Osprey Oil and Gas Ltd was granted a licence to explore for shale gas
The company is now expected to apply for planning permission later this year to drill in an area including Burnley, Hyndburn and Pendle.
It is the latest firm to take firm steps towards fracking – short for hydraulic fracturing – with other firms including Ineos Shale, IGas and Cuadrilla among those holding similar licenses in North Yorkshire, South Yorkshire, Nottinghamshire, Derbyshire, Lincolnshire, Cheshire and other parts of Lancashire.
Despite being heavily used in countries including the United States, fracking is a highly controversial process, with environmentalists saying it can contaminate the water supply, cause earthquakes and destroy natural landscapes.
Scotland, Ireland, France, Germany and the Netherlands are among the European countries that have put a stop to it.
But for the wider public, this unconventional drilling process being pursued in England is a complex engineering process that many don’t fully understand.
Here, we break down what fracking involves:
What does hydraulic fracturing mean?
This is a type of drilling technique that involves fracturing rock deep underground in order to extract shale gas.
Energy firms will drill at first vertically down into the ground at between 6,000ft and 10,000ft, and then horizontally by more than a mile.
Hairline cracks with a radius of about 300ft are then opened up in the rock by pumping in water, sand and some chemicals, allowing gas to flow into the pipes.
What kind of permission does an energy firm need to begin fracking?
Oil and gas companies that hope to explore for shale gas must first obtain a Petroleum Exploration and Development Licence (PEDL) from the Government’s Oil and Gas Authority.
This allows a company to pursue a range of oil and gas exploration activities, subject to necessary drilling and development consents, and planning permission from the local authority.
Once a company has negotiated the lease of land on which it wishes to frack, it must seek planning permission for pre-fracking research.
This includes seismic surveys, which provide 3D images of the underground resources, and a vertical drilling to obtain examples of the rock.
Should the firm decide there are sufficient shale gas reserves, it must seek further planning permission.
How long is a fracking site active?
There are three stages to fracking, with the final phase lasting decades.
Drilling contractors will typically create up to 30 wells over a five-week period, using a 180ft sub-structure similar in appearance to those used on offshore oil rigs.
A fracking team will then take over the site for about two weeks to open up the fissures in the rock and collect the shale gas through pipes.
Once this work has been completed, a production unit will create a small well pad of pumps feeding into green containers to extract the gas over many years.
The containers are connected to the national grid supply system for the lifespan of the well.
What are the dangers?
Opponents believe fracking carries a significant risk of contamination with hazardous chemicals, not least the water supply – where there have been numerous complaints of tap water being discoloured, causing illnesses and even being flammable in the USA.
There are those who argue it contributes to global climate change and destabilises underground rock formations to induce earthquakes.
They also question the economic sustainability of fracking, saying it would require thousands of wells that would transform the countryside, where natural landscapes would be destroyed and organic farmers would be under threat.
What do fracking companies say?
They contend that water supplies should not be affected because the piping structure should protect gas from leaking into the aquifer, the underground layer of rock from which groundwater can be extracted using a water well.
Pipes have up to seven layers, each reinforced by concrete, as they pass through the aquifer and are reduced to one layer of steel at about 3km deep.
Supporters also claim that fracking has helped to revolutionise the energy industry in the USA and that the UK could become a net exporter of gas, rather than spending money exporting from other countries.
They also believe the industry could create tens of thousands of jobs and attract billions in investment in communities that were once dependent on mining.
What is the UK Government’s position?
Believing shale gas has the potential to provide the UK with greater energy security, economic growth and jobs, the Government is encouraging its exploration to determine the potential.
It cites research by the British Geological Survey, which says there are 1,300 trillion cubic feet of gas reserves in northern England, and has handed out PEDLs to numerous energy firms to carry out surveys.
In terms of why gas is needed, it cites how it is used in every aspect of our lives – for heating homes, transport and in industry – and how natural gas accounted for just over a third of the UK’s energy usage in 2015.
But the Government has also pledged to have strong regulations to ensure safety on site and prevent any negative environmental impact.