Over the last few years, as the price of natural gas and oil became more expensive, the extraction industry investigated new methods for getting fuel out of the ground from sites which were previously thought uneconomical.  We have all heard of fracking by now, a controversial method of breaking up channels in bed rock to release shale gas.  (causing earthquakes in Blackpool). http://www.telegraph.co.uk/finance/newsbysector/energy/8864669/Cuadrilla-admits-drilling-caused-Blackpool-earthquakes.ht