Saudi Aramco, officially the Saudi Arabian Oil Company, is a Saudi Arabian multinational petroleum and natural gas company based in Dhahran, Saudi Arabia.
It is one of the largest companies in the world by revenue, and according to accounts seen by Bloomberg News, the most profitable company in the world. Saudi Aramco has both the world's second-largest proven crude oil reserves, at more than 270 billion barrels (4.3×1010 m3), and largest daily oil production of all oil producing companies.
Saudi Aramco operates the world's largest single hydrocarbon network, the Master Gas System. Its 2013 crude oil production total was 3.4 billion barrels (540,000,000 m3), and it manages over one hundred oil and gas fields in Saudi Arabia, including 288.4 trillion standard cubic feet (scf) of natural gas reserves. Saudi Aramco operates the Ghawar Field, the world's largest onshore oil field, and the Safaniya Field, the world's largest offshore oil field.
According to wikipedia