How the fracking process works
13 December 2012 Last updated at 10:46 GMT
The government has given the go-ahead for a firm to resume the controversial technique known as fracking to exploit gas in Lancashire.
The company, Cuadrilla, was stopped from fracking after two tremors near Blackpool.
Huw Clarke, a geologist with Cuadrilla, explained the fracking process to the BBC's John Moylan on site in Lancashire.