Oil and gas production has been the mainstay of the UAE economy since production began in the early 1960s. Abu Dhabi is the biggest oil producer in the UAE, controlling more than eighty-five per cent of the total oil output capacity and over ninety per cent of its reserves. Abu Dhabi also has the fourth largest natural gas reserves in the world; the Khuff Reservoir beneath the oil fields of Umm Shaif and Abu al-Bukhoosh ranks among the world's largest single gas reservoirs. These vast gas and oil accumulations are contained in ancient subterranean reservoirs. This map shows the structural trend of oil and gas fields in onshore and offshore areas of the UAE.
Anticlines and synclines are folded rock layers (due to compression) that are often associated with oil fields; however, anticlines, which are arch-shaped rock formations, form natural traps for hydrocarbons and are more commonly associated with oil and gas fields, as displayed on this map. Synclines, or trough-shaped rock layers, form natural traps for water and are usually associated with underground water supplies. The Emirate's principal offshore oil fields include Umm Shaif, Zakum, Mubarraz, Bunduq and Abu al-Bukhoosh, while the primary onshore oil fields are Asab, Bab, Bu Hasa, and Sahil.
