Natural-gas processing at ambient conditions (i.e., pentane and heavier) are called "natural-gas condensate" (sometimes also called "natural gasoline" or simply "condensate"). Natural gas is called "sweet gas" when relatively free of hydrogen sulfide; gas that does contain hydrogen sulfide is called "sour gas". Natural gas, or any other gas mixture, containing significant quantities of hydrogen sulfide, carbon dioxide or similar acidic gases, is called "acid gas." Raw natural gas can also come from methane deposits in the pores of coal seams, and especially in a more concentrated state of adsorption onto the surface of the coal itself. Such gas is referred to
Natural gas in the United States barrels per day in 2014. The US has been the world's leading producer of natural gas liquids since 2010, when US NGL production passed that of Saudi Arabia. Although the United States leads the world in natural gas production, it is only fifth in proved reserves of natural gas, behind Russia, Iran, Qatar, and Turkmenistan. The United States oil and gas industry is often informally divided into "upstream" (exploration and production), "midstream" (transportation and refining), and "downstream" (distribution and marketing). Petroleum and natural gas share a common upstream (exploration and production) sector, but the midstream and downstream sectors are largely