Union Ministry of Petroleum and Natural Gas has amended Petroleum and Natural Gas Rules 1959 to include shale in the definition of petroleum.
This change will allow private companies to explore and produce the resource in the blocks they already operate.
Earlier, definition excluded shale and therefore barred companies from exploiting it from fields that are producing conventional oil and gas or coal-bed methane.
Shale is distinguished from other mudstones due to laminated and fissile nature.
Shale gas is natural gas formed from being trapped within shale formations.
Shale gas is cheaper than natural gas, releases 50% less CO2, hence better source for generating electricity.
In India, potential shale gas sites are Cambay, Gondwana, Krishna-Godavari and Cauvery Basins.