Oil and Natural Gas Corporation Limited is an Indian company engaged in the exploration, development and production of oil, natural gas and value-added products. Its segments include Research and Manufacturing; and processing and marketing. The company's geographic segments include operations in India, which includes onshore and offshore areas, and outside India. It is also engaged in acquiring oil and gas acreage from outside India for exploration, development and production, downstream (refining and marketing of petroleum products), petrochemicals, power generation, liquefied natural gas (LNG) supply, pipeline transportation, SEZ. . (SEZ) development and helicopter services. It is engaged in offshore oil extraction, offshore natural gas extraction and offshore oil extraction services. Its subsidiaries include Mangalore Refinery and Petrochemicals Limited, ONGC Videsh Limited and Petronet MHB Limited.