Petroleum is a commodity that can influence geopolitical events as it is so required for survival in the 21^st century. Petroleum is used not just as a fuel, but as raw material in the production of other numerous essential commodities including food preservatives, parachutes, shoes, guitar strings, shampoo, anaesthetics, artificial limbs, yarn and many more. Thus, presence of petroleum is an indicator of prosperity of the region. No wonder petroleum is referred to as liquid gold, as it has diversified uses and is scarce just like the metal. Entire wars have been fought over control of this liquid gold.

Crude petroleum occurs in sedimentary rocks of tertiary period. Oil exploration and production, in India, was systematically taken up after the Oil and Natural Gas Commission (ONGC) was set up in 1956. Till then, Digboi in Assam was the only oil producing region. After 1956, new oil deposits have been found at the extreme western and eastern parts of the country.

In Assam, Digboi, Naharkatiya and Moran are important oil producing areas. The major oilfields of Gujarat are Ankaleshwar, Kalol, Mehsana, Kosamba and Lunej. Mumbai High which lies 160 km off Mumbai was discovered in 1973 and production commenced in 1976. Oil and natural gas have been found in explanatory wells in Krishna-Godavari and Kaveri basin on the east coast.