Shale gas is overrated .In its dry form its expensive to extracti.e. dry gas. costs around minimum 3.5$/per mcf . But if it is NGL's then its very lucrative. At least this is what the drillers at Eagle Ford,Texas say. Then you have the Bakken , where there is massive light oil shale which is even better.
Marcellus shale is a failure and Chesapeake's investments are ruined due to McClendon's Ego and his disastrous investment in those zones. Overall I see a lot more scope for deep gas in India , but GOI will never try to drill into the crystalline basement rocks in WB,Kashmir like how the soviets,vietnamese did.GOI is on the payroll of Saudi Wahabbis to keep india dependent.