Shale gas exploration calls for use of two major stressed resources — land and water — and experts have been repeatedly cautioning about India becoming overenthusiastic about shale.
It takes about 3-4 million gallons of water to be put into each well for the ‘hydraulic fracturing’, to release the gas locked in shale deposits. This water comes back to the surface contaminated and needs to be treated before it is let out.
In a report it brought out in June, The Energy and Resources Institute (TERI), underlined the dangers of using groundwater — needed for ‘hydraulic fracturing’ to release gas from shale. TERI raised a question: ‘Should we further endanger a rapidly depleting resource (water) on which all life depends?’ Its answer was “a resounding NO”.
A few months ago, the Director-Exploration of ONGC, N.K. Verma, told
To start with the potential is “moderate”— around 80-90 trillion cubic feet of gas. (A United States Geological Survey report puts India’s shale resources at a more modest 65 trillion cubic feet.)
Comparatively, another source of non-conventional natural gas, coal bed methane, has a much larger potential and the TERI report called for more attention on this. India’s CBM potential is estimated at 450 tcf.
Eco problems
India has 293 billion tonnes of coal lying under its soil, but, as is now well known, there are environmental problems with its exploitation. However, if you do ‘underground coal gasification’, you are looking at a potential of 6,900 trillion cubic feet of gas. Shale pales in comparison.