The South Pars/North Dome field is a natural-gas condensate field located in the Persian Gulf. It is by far the world's largest natural gas field, with ownership of the field shared between Iran and Qatar. According to the International Energy Agency (IEA), the field holds an estimated 1,800 trillion cubic feet of in-situ natural gas and some 50 billion barrels of natural gas condensates. On the list of natural gas fields it has almost as much recoverable reserves as all the other fields combined. It has significant geostrategic influence.

Natural gas is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane (97%) in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbon dioxide, nitrogen, hydrogen sulfide, and helium are also usually present. Methane is colorless and odorless, and the second largest greenhouse gas contributor to global climate change after carbon dioxide. Because natural gas is odorless, odorizers such as mercaptan are commonly added to it for safety so that leaks can be readily detected.