With crude oil prices in the country reaching stratospheric levels, (it was a whopping $ 92.17 per barrel , at the time of writing) the recent shale gas discovery is being touted as the much-needed breakthrough. On January 27, 2011, Oil & Natural Gas Corp (ONGC) announced that it had hit upon a shale gas source at Icchapur, near Durgapur, in West Bengal, at depths of 1700 m below the ground. With a view to consolidating its position in the energy market, the company now plans to explore the shale reserves of Cambay, Kaveri-Godavari, Cauvery and Assam-Arakan Basins.
The shale gas, found in pore spaces and fractures of the shale rock, is extracted by a process known as Hydraulic fracturing or simply “fracking”. It involves injection of pressurized water (hence the term hydraulic), containing sand and chemicals into rock formations to fracture it, creating perforations for the efficient release of the gas. The sand, due to its granular nature, serves to keep the cracks open, while the mixture of chemicals takes the liquid to places, inside the cracked rocks, where the water cannot reach.
This discovery of indigenous gas resources can lead to seismic shifts in the global political scenario. As India gradually becomes self-reliant in the energy sector, it will signal the end of India’s perpetual dependence on Iran, Saudi Arabia and the other oil-producing countries for crude oil and natural gas (according to IAGS, it currently imports approximately 70% of its oil from Gulf countries).
In addition to that, it will obviate the need of investing billions of dollars in overseas oilfields; also India’s frantic search for potential oil suppliers can finally end. On the domestic front, shale gas boom could produce thousands of jobs, as seen in US, where, according to Energy Tomorrow, natural gas production in the Marcellus (Appalachian Basin) added 57,000 new jobs in 2009 itself. However, one needs an almost Panglossian optimism to believe that shale gas can be the answer to our country’s domestic energy-related demands.
Apart from the extraction technology itself being complicated and expensive, the amount of shale gas present should be enough so as to make the venture economically viable. In other words, shale rock formations should be spread over extensive areas. But that is just the tip of the iceberg, as far as shale gas extraction problems are concerned.
Hydraulic fracturing process can lead to substantial groundwater contamination on account of the various chemicals used in the drilling fluid (the fluid can seep into water tables if leaks are present in the casings). While it is still unclear as to what chemicals are being used by the ONGC in its drilling fluid, but diesel fuel (which contains benzene, ethylbenzene, toluene, xylene, and naphthalene) is the substance normally used along with other substances like methanol, formaldehyde, ethylene glycol. Among these, benzene is a human carcinogen (cancer-causing agent) while an exposure to toluene can cause brain, liver and kidney damage.
Moreover, after fracking, the fracturing fluid (containing toxic substances), has to be pumped out; the fluid returns to the surface from where it is pumped to a holding pond, which in turn creates the problem of toxic waste water disposal.
It has also been reported that at places in Louisiana, US, at the site of Shell’s shale operations, wells gave off such copious amounts of methane that people in nearby houses had to be evacuated, as methane, apart from being a highly combustible gas, can cause death by asphyxiation.
Contaminated groundwater, toxic waste water, methane gas pollution – constitutes every environmentalist’s worst nightmare – a nightmare which, in the absence of assurances from the oil-companies and the government, may very well turn into reality, if the potential hazards of the extraction process continue to be ignored.