NISOC is incorporated 1971 in Masjed Soleyman, Khouzestan as Oil Service Company of Iran (OSCO).[2][3] Currently NISOC is Iran's biggest oil producer, and produce 3 million barrels of oil per day. the company is active in a land area more than 400,000 km² with headquarters in Ahvaz. NISOC is producing about 83% of all crude oil and 17% of natural gas produced in Iran[4] and ranks as the Iran's biggest oil company.[5]