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 in the United States natural gas and natural gas liquids. The exploration for and production of natural gas and petroleum form a single industry, and many wells produce both oil and gas. Because of the greater supply, consumer prices for natural gas are significantly lower in the United States than in Europe and Japan. The low price of natural gas, together with its smaller carbon footprint compared to coal, has encouraged a rapid growth in electricity generated from natural gas. Between 2005 and 2014, US production of natural gas liquids (NGLs) increased 70%, from 1.74 million barrels per day in 2005 to 2.96 million