Figure 12: Shale oil and gas basins of India

Krishna Godavari basin, located in eastern India, is considered to hold the largest shale gas reserves in the country. The basin is estimated to have around 27 Tcf of technically recoverable gas. The Cauvery basin in Tamil Nadu state is estimated to have recoverable shale gas reserves of 7 Tcf. The Cambay basin in Gujarat is the largest basin in the country, spread across 51,800 sq km. As per the initial studies, around 20 Tcf of gas is estimated as technically recoverable reserves in the Cambay basin. ONGC had drilled the country’s first shale gas well in Jambusar in the October in 2013 to exploit the natural gas trapped within the shale formations located in Cambay basin.

Methane Hydrate

Methane Hydrate is a cage-like lattice of ice inside of which are trapped molecules of methane, the chief constituent of natural gas. It is found in sea-bed that forms at low temperatures and high pressure. It is also found in onshore deposits in the permafrost of northern Canada and Russia. Heating the deposits or lowering the pressure will release gas from the solid. One litre of solid hydrate releases around 165 litres of gas.