The first use of hydraulic fracturing was in 1947. The modern fracturing technique, called 'horizontal slickwater fracturing', was first used in 1998. It made the extraction of shale gas economical. The energy from the injection of a highly pressurized fluid creates new channels in the rock, which increases the extraction rates and recovery of hydrocarbons. In 2010 it was estimated that 60% of all new oil and gas wells worldwide were being hydraulically fractured. As of 2012, 2.5 million hydraulic fracturing jobs have been performed on oil and gas wells worldwide, more than one million of them in the United States.
Proponents of hydraulic fracturing point to the economic benefits from the vast amounts of previously out of reach hydrocarbons. Opponents point to potential environmental effects, such as contamination of ground water, risks to air quality, the migration of gases and hydraulic fracturing chemicals to the surface, surface contamination from spills and flowback and the health effects of these. For these reasons hydraulic fracturing has come under scrutiny, with some countries suspending or banning it.
However, some of those countries, including most notably the United Kingdom, have recently lifted their bans. Now they have regulations instead of outright prohibition. It turns out that the UK has huge gas reserves if fracking is used.
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