Oil India Limited (OIL) is the second largest hydrocarbon exploration and production Indian public sector company with its operational headquarters in Duliajan, Assam, India. The company is a state-owned Navratna under the administrative control of India's Ministry of Petroleum and Natural Gas with its corporate offices in Noida in the New Delhi-NCR region.
OIL is engaged in the business of exploration, development and production of crude oil and natural gas, transportation of crude oil and production of liquid petroleum gas. The company's history spans the discovery of crude oil in the far east of India at Digboi, Assam in 1889 to its present status as a fully integrated upstream petroleum company.