It is very important for the development of a country because it makes industrialisation possible.The below mentioned fact supports it's importance:
97% of the energy required for transportation is provided by crude oil. A product called Premium Motor Spirit that is derived from crude oil is essential for vehicles.
U.S.A. still depends on crude oil and gas for the generation of 20% of its electricity.
Crude oil is also essential for the production of plastics, paints, petrochemicals and synthetic fabrics.
The economies of several nations also depend on the export of crude oils.