Fracking is a technique involving pumping water and chemicals into shale rock at high pressure to extract gas.

BBC: Lancashire's shale gas estimated at ?136bn by Cuadrilla

Fracking is a controversial process that involves pumping water and chemicals into shale rock at high pressure to extract gas.

BBC: Cuadrilla bids to resume Westby and Banks fracking

Fracking is a technique of shale gas extraction that involves pumping water and chemicals into shale rock at high pressure to extract gas.

BBC: Lancashire shale gas 'could be worth billions'

It extracts oil from the ground using a method called fracking - pumping down a mixture of sand, water and chemicals at high pressure.

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Under the process of fracking, oil or gas is extracted from shale rock by pumping a mixture of sand, water and chemicals into the rock at high pressure.

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