In January last year, the US Energy Information Administration estimated that India held 38 trillion cubic feet of proven natural gas reserves.
That was good enough for the needs of the nation for 29 years, it was said.
What if that figure was upped to a fantastic 527 trillion cubic feet?
Yes, 527 trillion cubic feet of gas, of which 50%, or over 260 tcf, were recoverable?
That amount of fuel could last for at least 200 years and would potentially be the fifth biggest hoard in the world.
China has the most, followed by US and Argentina.
A M Dayal, an emeritus scientist with the National Geophysical Research Institute (NGRI) in Hyderabad, said his scientists have identified 28 sedimentary basins of shale gas (natural gas found trapped in shale formations under the ground), including ten potential producing basins, across India.
These have been classified according to their hydrocarbon potential, and hold an estimated 527 trillion cubic feet (tcf) of reserves, he said.
With government policy framework on shale gas exploration expected in the next 18-24 months, and given industry’s keenness to get into exploration of the clean non-conventional energy source that is also less expensive — no processing is necessary — India can look forward to commercial production of shale gas in the next five years or by 2017, Dayal said.
Shale gas is being increasingly tapped across the world as conventional energy sources like oil and coal turn scarce and expensive.
For instance, the US has been recovering shale gas for several years. Its reserves at 2009-end were estimated at 60.6 trillion cubic feet. By 2011, the figure rose to 827 trillion cubic feet. Shale production is projected to increase from 23% of total US gas production in 2010 to 49% by 2035. Unconfirmed data even suggest that shale gas usage has helped reduce the cost of gas in the US. China is among the countries that are now looking at shale gas as source of energy.
According to scientists working on Indian shale gas, recovery rate of up to 50% is much higher than the 30% in oil and gas reserves. “Unlike conventional hydrocarbon traps, shales cover large areas and they remain a source of gas for a very long time,” said Dayal.
With the US getting into shale gas in a big way, oil and gas exploration companies in India are “ready to get into shale gas sector. They all know India is a big market”, said Dayal.
A stumbling block could be lack of a clear policy framework. Shales are available equally in the blocks already allotted to oil exploration companies. But they can’t touch the shale yet. Shale gas blocks have to be separately allotted for exploration.
However, the NGRI scientists can work on developing shale gas in India, independent of the guidelines.
“Under the 12th Five-Year Plan, we are planning to work in the Canbay basin, the Assam-Arakan basin, the K-G basin and the Damodar basin. When the exploration companies are given the blocks, they have to get the core of the shale and analyse it for geo-chemistry and petro-physics results. That will decide whether or not it is economic to take the project forward. That’s where we plan to play a role since we have the infrastructure and the grant of the Oil Industry Development Board,” said Dayal.
A potential problem in India could be that shales are mostly found about 2,000 metres deep on shore, in areas of human habitation, unlike oil drilling that takes place offshore. Specially designed water borewells may be needed in such areas to tackle escaping methane gas. Use of high-power compressors and other equipment could also unsettle local populations, while shale drilling could affect ground water reserves.
But all such challenges are not insurmountable, scientists said.
“There is an immediate need for us to tap the shale. Conventional sources are either expensive or drying up. After Bombay High, there is no big discovery on the conventional front. Even the reserves in D6 are proving to be uncertain,” Dayal said.