The crude petroleum is a mixture of combustible hydrocarbons in solid, liquid and gaseous forms. Petroleum products are used as fuel, lubricant, material for manufacturing synthetic derivatives and chemicals required in industries. Petrol, kerosene, diesel, detergents, synthetic fibres, plastics, cosmetics, etc. are important products derived from petroleum.


Petroleum occurs in anticlines and fault traps. In India, it is found in the sedimentary rock formation. Most of such areas lie in the Assam, Gujarat and off shore areas along the western coast.

Oil Refineries

Oil extracted from the wells is crude oil and contains many impurities. It cannot be used directly. The crude petroleum taken from oil fields needs to be refined before it can be used. Oil refining is really a big chemical engineering industry involving a complicated process.

There are two types of refineries in India: (a) field based and (b) market based. Digboi is an example of field based and Barauni is an example of market based refinery.