State the importance of petroleum as an energy resource. Mention any four oil fields of India.
Petroleum or mineral oil is the next major energy source in India after coal. It provides fuel for heating and lighting, lubricants for machinery and raw materials for a number of manufacturing industries.
Four major oilfields of India are
(i) Mumbai High
(ii) Gujarat — Ankeleshwar and Kalol
(iii) Assam — Digboi, Naharkatiya and Moran
(iv) Rajasthan, Mangala, District Barmer