Oil and Natural Gas Corporation Limited is an India-based company, which is engaged in exploration, development and production of crude oil, natural gas and value-added products. Its segments include Exploration and Production; and Refining and Marketing. The Company's geographical segments include operations in India, which includes Onshore and Offshore, and Outside India. It is also involved in acquisition of oil and gas acreages outside India for exploration, development, and production, downstream (Refining and marketing of petroleum products), petrochemicals, power generation, liquefied natural gas (LNG) supply, pipeline transportation, special economic zone (SEZ) development and helicopter services. It is involved in offshore extraction of crude petroleum, offshore extraction of natural gas and services incidental to offshore oil extraction. Its subsidiaries include Mangalore Refinery and Petrochemicals Limited, ONGC Videsh Limited and Petronet MHB Limited.