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What's the current situation?

Q&A: shale gas and fracking

How does fracking work, what are the environmental concerns and how much could it contribute to the UK's energy demands?

Shale gas has been transformational in the US, one of the world's biggest energy markets. Photograph: Bloomberg/Bloomberg via Getty Images

What are shale gas and fracking?

  • Shale gas is natural gas trapped in rocks deep underground
  • It's extracted by "fracking": pumping water, sand and chemicals into the rocks
  • Concerns have been raised about pollution, climate change and safety impacts

Shale gas is natural gas stored deep underground in fine-grained sedimentary rocks. It can be extracted using a process known as hydraulic fracturing – or "fracking" – which involves drilling long horizontal wells in shale rocks more than a kilometre below the surface. Massive quantities of water, sand and chemicals are pumped into the wells at high pressure. This opens up fissures in the shale, which are held open by the sand, enabling the trapped gas to escape to the surface for collection (see graphic).

Advocates argue that exploiting the world's potentially vast shale gas deposits will help keep energy affordable and cut consumption of dirtier coal. But sceptics claim fracking is dangerous and polluting, and that tapping into extra natural gas supplies will boost rather than reduce planet-warming carbon emissions.

Fracking is a nightmare! Toxic and radioactive water pollution. Tap water you can set on fire. Earthquakes. Runaway climate change. To produce expensive gas that will soon run out.
Campaign group Frack Off

Shale has changed the equation. Abundant, relatively low-priced supplies now make natural gas a highly competitive alternative to both nuclear and wind power and even to coal generation. It has the added advantage of being relatively low-carbon.
Energy commentator Daniel Yergin

What's the current situation?

  • Shale gas production is rising quickly in the US
  • Fracking has begun in the UK, Australia, China and other nations
  • France and Bulgaria have banned fracking amid concerns

In the US, shale gas has scaled up rapidly to account for around a quarter of the country's natural gas extraction. Fracking is also now underway in many other countries, including China, Poland and the UK, where drilling company Cuadrilla Resources claims to have found vast reserves at its site near Blackpool.

But as fracking sites have multiplied so have the controversies. A 2010 film showed people near one US site setting tap water on fire and in 2012 a whistleblower claimed fracking could poison New York's drinking water. Meanwhile, Cuadrilla's UK operation was put on hold after causing tremors (tiny earthquakes), but a report by the UK government's advisers published in April 2012 gave the green light to fracking despite acknolwedging the link between the process and 2011's earthquakes.

Such concerns have seen France and Bulgaria ban fracking and campaigners are calling for other countries and US states to follow suit. But Australia recently gave fracking the go-ahead.




Date: 2016-01-14; view: 702


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