Natural gas before the natural gas can be transported. Natural gas extracted from oil wells is called casinghead gas (whether or not truly produced up the annulus and through a casinghead outlet) or associated gas. The natural gas industry is extracting an increasing quantity of gas from challenging resource types: sour gas, tight gas, shale gas, and coalbed methane. There is some disagreement on which country has the largest proven gas reserves. Sources that consider that Russia has by far the largest proven reserves include the US CIA (47 600 km³), the US Energy Information Administration (47 800 km³), and OPEC (48
Natural gas prices deal between the U.S. and Europe opens up access to cheap American natural gas, which allow Europe to diversify its supply base, but may threaten the Renewable Energy transition. Currently, Europe's main natural gas supplier is Russia. Major pipelines pass through Ukraine and there have been several disputes on the supply and transition prices between Ukraine and Russia. In September 2013, it was reported that multiple factors have conspired to cause Europe as a whole to decrease its use of natural gas and make more use of coal. The report also contains updated price trends. In South America, the second