India Shale Gas: Environmental Concerns

Shale gas is natural gas trapped in very fined grained sedimentary rocks like shales. These rocks are not very permeable. To release the gas trapped in the tiny pore spaces, the rock is fractured by injecting water, sand and various chemicals into it at very high pressure. Several million gallons of fresh water is needed for such ' fracking' activity at any one site. 

Shashikant Yadav, Gopal K Sarangi and M P Ram Mohan in an essay in the Economic and Political Weekly explain the environmental concerns that shale gas production poses in India.

Regarding the guidelines for environmental management released by the government -

Further, the guidelines mention that water management is one of the key concerns. They state that the major and prime difference being in the hydraulic fracturing technologies requiring a large volume of water; the activities are likely to deplete water sources and cause pollution due to the disposal of produced water. However, instead of dealing with the water-specific issues, the guidelines (apart from explaining existing provisions) stated that the generic environment clearance process adopted by the Ministry of Environment, Forest and Climate Change (MoEFCC) will suffice to ascertain water-related issues posed by fracking. But, MoEFCC has not laid down any specific guidelines, policies, or manuals differentiating between conventional and unconventional gases to grant environment clearance.  More recently, despite the gaps, on 1 August, 2018, the cabinet approved a policy allowing companies to exploit shale gas in contract areas that were primarily allocated to exploit conventional gas.

..and this in the context of the ambiguous legal framework surrounding groundwater -

Considering the limited water legislation in India, the implementation of fracking may result in geopolitical and legislative complexities. For instance, shale rocks are usually adjacent to rocks containing useable/drinking water known as “aquifers.” While implementing the hydraulic fracking, the shale fluid can easily penetrate to aquifers leading to groundwater contamination. This contamination may result in methane-poisoning of water used for drinking and irrigational purposes. To avoid such contamination, as per industry standards, a project proponent must maintain a distance of 600 metres between aquifers and fracture zones (Davies et al 2012).

The Indian water legal regime is far away to make such specific observations, as aquifers are not defined in any of the Indian environmental regulatory or legal regime leading to a free pass for unregulated mixing of shale fluid and aquifers. Moreover, the landless have no right to groundwater, and accordingly peasants and tribal communities who have no ownership rights over land have no right on groundwater. Also, a project proponent may easily exploit groundwater while implementing the hydraulic fracking process with none or limited accountability of their actions.  In such a situation, the intent of “Public Trust Doctrine” is defeated, and the precautionary principle will be non-implementable.

Open Access.

Report: Global Shale Gas Development And Water Availability

This is something that I have written about before in the context of shale gas development from Indian sedimentary basins. The availability of fresh water might set up conflicts with agriculture demands and limit exploitation of shale gas.

A report by the World Resources Institute on the global situation points out the same problem elsewhere in many areas of the world.

38 percent of shale resources are in areas that are either arid or under high to extremely high levels of water stress

19 percent are in areas of high or extremely high seasonal variability; and

15 percent are in locations exposed to high or extremely high drought severity.

Furthermore, 386 million people live on the land over these shale plays, and in 40 percent of the shale plays, irrigated agriculture is the largest water user. Thus drilling and hydraulic fracturing often compete with other demands for freshwater, which can result in conflicts with other water users. This is particularly true in areas of high baseline water stress, where over 40 percent of the available water supplies are already being withdrawn for agricultural, municipal, or industrial purposes.

China, Mexico, South Africa and India all have sedimentary basins with shale gas potential located in areas of high water stress i.e. extraction of either surface water and/or groundwater exceeds natural replenishment.

WRI Full Report On Shale Gas and Water Availability
WRI Executive Summary On Shale Gas and Water Availability

The report relies on EIA estimates of technically recoverable shale gas and tight oil. These numbers may be subject to revision as more detailed studies are taken up in sedimentary basins in India and other countries as well.

India is still some way away from exploitation of shale gas. It faces many other problems besides availability of water. This earlier post summarizes these issues.

Earthquakes Triggered By Fluid Injection Along Faults

A friend sent me this abstract published in the Seismological Society of America 2014 annual meeting-

Triggered Earthquakes Far From the Wellbore: Fluid Pressure Migration and the 2008-2014 Jones Swarm, Central Oklahoma

KERANEN, K. M., Cornell University, Ithaca, NY, USA, keranen@cornell.edu; WEINGARTEN, M., University of Colorado, Boulder, CO, USA, matthew.weingarten@gmail.com; BEKINS, B., USGS, Menlo Park, CA, USA, babekins@usgs.gov; GE, S., University of Colorado, Boulder, CO, USA, Ges@colorado.edu; ABERS, G. A., Lamont-Doherty Earth Observatory, Palisades, NY, USA, abers@ldeo.columbia.edu

Earthquake relocations and hydrogeologic modeling show that the Jones earthquake swarm, occurring near Oklahoma City since 2008, is linked to disposal wells injecting high volumes of water along the Nemaha Fault. Felt and recorded earthquakes in the Jones swarm began in 2008, approximately 15 km from four high-volume wastewater disposal wells. These wells dispose of ~2-3 million barrels per month (4-5 million barrels per month cumulatively) in two adjacent locations on the downthrown side of the Nemaha fault. Earthquakes are observed to migrate away from these high-volume disposal wells up the structural dip and down hydraulic gradient. Hydrogeologic modeling shows that the increase in subsurface pore pressure resulting from the fluid injection is of sufficient magnitude to trigger slip on pre-existing faults. The region of increased pore pressure grows outward through time with injection. The larger, mapped faults in the subsurface may act as conduits or guides to fluid flow, and may transmit fluid pressure into basement. Our results demonstrate that wastewater disposal can raise fluid pressure and trigger earthquakes at tens of kilometers from the wellbore on existing faults.

Fracking for shale gas by itself has not been shown to trigger biggish earthquakes but the wastewater disposal that follows fracking has.

How does increasing pore pressures increase the chances of slip along a fault? High pore pressures reduce the effective normal stresses acting perpendicular to faults. These normal stresses resist shear movements i.e. fault blocks from sliding past each other. With increased pore pressure the effective normal stresses decreases, allowing shear movements.  Geophyicist Mark Zoback explains in more detail about the risks and management of seismic risk posed by wastewater disposal.

India Energy Report- Some Rambling Thoughts

The latest from the U.S. Energy Information Administration. For those who follow the energy sector, nothing terribly new here, but it is a useful document to keep bookmarked for quick reference.

Meanwhile, Swaminathan Aiyar takes an optimistic look at the future of methane hydrate deposits which he thinks can provide significantly to India's energy needs. These deposits are formed when methane is trapped within a crystalline cage of water molecules. They occur in cold deep sea sediments and also onshore in permafrost settings.There are estimates that resources in sediments in India offshore basins on both the west and east coast may be around 1800-1900 trillion cubic meters.

My take is that whatever the estimates, we may be decades away from successfully exploiting them. Of more relevance over the short to medium term is onshore shale gas. Estimates for those vary wildly from an earlier EIA estimate of about 63 trillion cubic feet to a revised USGS estimate of only 6-7 trillion cubic feet to a figure often quoted in the India media of about 500 trillion cubic feet to 300-1200 trillion cubic meters! These disparate estimates only underscores the need for a more detailed exploration of Indian sedimentary basins.

Some Good Readings About U.S. Oil In Shale Resources

I go over to the Oil Drum often to catch up on news and analysis on oil and natural gas. A few that caught my eye over the holiday period:

1) Does the U.S. Really Have More Oil than Saudi Arabia? - some fundamentals about the difference between shale oil and tight oil, and resources and reserves cleared up.

2) Bill O'Reilly Is Misinforming Americans About Oil Supplies - U.S oil exports and imports and the link to gasoline prices and jobs.

3) Shale Oil: The Latest Insights -  Development of "shale oil" resources and impacts on the shale gas production.

4) Gas Boom Goes Bust: On the future of the shale gas industry.

The Oil Drum has generally been giving a more cautious and conservative long term perspectives on the recent elation over shale gas and new discoveries of "shale oil".

Geophysicst Mark Zoback On Fracking

Another terrific geology related talk on Generation Anthropocene. Geophysicist and shale gas expert Mark Zoback attempts to clear up the many misconceptions about fracking. He doesn't minimize or take lightly the negative impact of shale gas drilling, but rather puts it in a broader context. The greater risk of contaminating overlying aquifers is not from the act of hydraulic fracturing itself but from improper well construction and from leaky ponds which are constructed to store waste water that flows back out of the formation. This water may contain metals like iron or arsenic flushed by reaction with the shale. So actually according to him, there is nothing in the fracking fluid that is dangerous. But that fluid after reacting with the rock may become toxic.

Shale gas drilling companies don't have to disclose the exact composition of the fracking fluid as they have an exemption under the Clean Water Act. But perception does matter. As Mark Zobeck points out, there was growing support for nuclear power in the U.S. until the accident at Fukushima occurred. Public perception about risk can reverse major energy policy decisions regardless of the actual risk. If that is so, then why slow down or kill the shale gas goose? Perhaps it will be wiser to change policy and to come clean about fracking fluids.

Meanwhile, on the topic of shale gas in India,  a reader wrote in a comment on an earlier post I had written about Indian shale gas prospects:

US geological survey says the total shale gas reserves to be 6.1 Tcf, contrary to 63 Tcf by EIA. What are your views on this?

That is a major downgrade for Indian shale gas prospects. I could only suggest this possibility:

thanks Dakshina.. yeah.. i saw those figures.. hard to say but downward revisions are going on in many other basins around the world.. perhaps the actual recovery rates observed from shale gas wells i.e. their performance over a longer term have not been as good as initially projected..leading to downward revision of technically recoverable resources in other areas as well.. or maybe it has to do with the reassessment of the basic geological data.. can't say for sure without reading more details.. ///

Also worth reading is another article by Mark Zoback on the seismic risk posed by shale gas drilling and waste water disposal.

Indian Baked Beans And American Natural Gas

This bean is an annual legume. The New York Times has an interesting article on the sudden demand from U.S. shale gas drillers for the guar bean grown in the arid state of Rajasthan. The bean powder is used in making fracking more effective.

Guar, a modest bean so hard that it can crack teeth, has become an unlikely global player, and dirt-poor farmers like Mr. Singh have suddenly become a crucial link in the energy production of the United States.

For centuries, farmers here used guar to feed their families and their cattle. There are better sources of nutrition, but few that grow in the Rajasthani desert, a land rich in culture but poor in rain. Broader commercial interest in guar first developed when food companies found that it absorbs water like a souped-up cornstarch, and a powdered form of the bean is now widely used to thicken ice cream and keep pastries crisp.

But much more important to farmers here was the recent discovery that guar could stiffen water so much that a mixture is able to carry sand sideways into wells drilled by horizontal fracturing, also known as fracking. 

The worry is that guar production in Rajasthan depends entirely on a good monsoon. So far this year rains have been deficient. Based on previous years surging sales, farmers have suddenly come into money and are spending freely. Hope the monsoons are normal this year too and one also hopes that poor farmers who have money to spend take sensible advice on managing their new found incomes.

A second worry and one for Indian agriculture is - will excessive demand for Guar, not just from the U.S., but from other countries including eventually from India start eating into farmland currently growing food crops?..Unless off course an alternative to Guar is found.. a possibility that Rajasthan farmers should also acknowledge and prepare for.

Estimating Coal Bed Methane Volume And Some Other Energy News

Via Geology.com I came across this short tutorial on estimating available coal bed methane. Gas is adsorbed in the micro-pores within the coal with smaller amounts available as free gas in fractures. The gas content available is estimated using a Langmuir isotherm:

Source: Baker Hughes Reservoir Blog

Short but effective presentation I thought.

In other energy news, India is ready to open up bidding for exploration of shale gas in six basins, namely Cambay, Assam-Arakan, Gondawana, KG onshore, Cauvery onshore and the Indo Gangetic basin by end of 2013. Early estimates suggest that four of these basins, Cambay, KG onshore, Cauvery and part of the Gondwana (Damodar valley basin) contain up to 63 trillion cubic feet of technically recoverable shale gas. These numbers are sure to be modified as these and other basins are probed in more detail.

Finally, Amol Sharma at India Real Time takes a closer look at "Coalgate", a controversy over the Indian government allocating coal mining blocks to companies instead of auctioning them in an open bidding process. The loss to the exchequer according to the Comptroller and Auditor General calculation is about $200 billion.

What all the media hype though has missed is that the report has a lot to say about the shortfall in coal production:

The lion’s share of the report doesn’t deal with any of the issues above that have caused such an uproar, but rather India’s coal production shortfall. There’s plenty of blame for Coal India, which produces 81% of the coal in the country and is a lifeline for power generation firms. Between March 2008 and March 2011, Coal India failed to supply 54 million tons of coal it had promised companies. The report also asks why the private companies that have been “captive mines” – the so-called windfall gainers – have been so slow to get going with production. It says only 28 captive coal blocks are producing out of 194 allocated by the government. It is fair to ask why this is the case. Are there delays in getting government clearances, or are companies being inefficient?

Indian potential coal reserves are about 350 billion tons, making it the fourth largest reserves in the world, but according to coal market consultants Wood McKenzie, the future marketable reserve i.e. marketable production by 2030 is just 18 billion tons. That estimate might reflect a complex mix of conditions such as a lack of confidence in India sorting out issues related to regulatory clearances and land acquisition problems along with shortage in skilled manpower and advanced technology.  India has to import coal to meet shortfalls in domestic supply.

The Economic Times reports that coal imports could increase substantially in the future from 80 million tons per year in 2011 to 400 million tons per year by 2030, especially if domestic prices are raised to be on par with international prices.  Australia and Indonesia are major suppliers of coal to India.

World Water Day: Water Water Everywhere ...And Shale Gas

Its World Water Day.

Near my house a big site is being developed. The builder excavated a huge pit about 40-50 feet deep for underground parking only to find he had hit a prolific aquifer.

My rough calculations suggest that the hole contains on the order of 15 -20 million liters of water. That sounds a lot but I was struggling to give it a context. Then this morning I read an article on Fracking, Methane and Food Security. Fracking or hydraulic fracturing is the process of injecting shale rock with a mixture of water, sand and chemicals to pry open the shale and release the tightly bound natural gas.

Here is what the article says about the amount of water used by each well being fracked -

 “Every time a gas well is fracked, 4 to 9 million gallons of water are injected into the ground. A single well can be fracked up to 12 separate times, adding up to over 100 million gallons of freshwater used in the lifetime of a well.” (waterdefense.org)

4-9 million gallons injected every time a gas well is fracked. That's on the order of 20 odd million liters of water, as much as is contained in that hole near my house.

My neighborhood is not depending on groundwater right now, but may have to in the not so distant future. Shale gas though will be extracted in the future from wells drilled in rural India, which depends a lot on groundwater. Farmers use it for drinking purposes as well as irrigating their fields. The gas will be in sedimentary formations a couple of kilometers below the surface, but the water for fracking will be taken from much shallower aquifers that the farmers rely on for their livelihood.

Each time a gas well is fracked, 20 million liters of water will have to be diverted from aquifers underlying their fields for getting the natural gas out. Over the lifetime of a well over 400 million liters of water may be consumed by one well and in an area few tens of sq km, there may be scores of such shale gas wells.

Its early days in our goal to exploit shale gas from various Indian sedimentary basins. Let us quantitatively assess the state of our aquifers besides exploring for shale gas. Let's educate our farmers on how much water shale gas drilling is likely to use up. The residents of central Pune can afford to pump all of 20 odd million liters of groundwater away and still see water gushing out of their taps.

Farmers in the dusty hinterlands may not afford that luxury.

Natural Gas: Expectations Fulfilled?

Couple of articles on the expectations surrounding natural gas -

Over at the Barrel, John Kingston points to an article by Mriganka Jaipuriyar on the delays and production problems at India's giant natural gas field KG-D6 in the east coast Krishna Godavari basin.

Across the continents, Ian Urbina of the New York Times dives into industry memos and internal emails expressing skepticism about the potential of shale gas in the U.S to remain a vast and profitable source of energy in the future. 

India Basin-Wise Shale Gas Estimates

Sometime back I had posted a graphic of Indian sedimentary basins and the potential of shale gas from these basins. Currently India has reserves of about 38 trillion cubic feet (Tcf) of conventional natural gas i.e. gas stored in pore spaces of coarser permeable sedimentary rocks like sandstones.

I had mentioned that shale gas i.e. natural gas trapped in very fine grained, impermeable shales might add substantially to the existing conventional natural gas reserves. I did not have any numbers to put out at that time.

Now the U.S Energy Information Administration (EIA) has come out with a report (51 mb) on global shale gas potential that includes some Indian sedimentary basins as well. The report has been prepared for the EIA by Advanced Resources International, a company based in Virginia, U.S.

About 70 shale formations from 48 basins in 32 countries were studied. Here is the global summary in terms of shale gas potential. The report only partially estimates shale gas resources since it excludes Russia and the Middle East. It also excludes offshore basins and many other onshore basins for which data is not available:

Although the shale gas resource estimates will likely change over time as additional information becomes available, the report shows that the international shale gas resource base is vast. The initial estimate of technically recoverable shale gas resources in the 32 countries examined is 5,760 trillion, cubic feet, as shown in Table 1. Adding the U.S. estimate of the shale gas technically recoverable resources of 862 trillion cubic feet results in a total shale resource base estimate of 6,622 trillion cubic feet for the United States and the other 32 countries assessed. To put this shale gas resource estimate in some perspective, world proven reserves of natural gas as of January 1, 2010 are about 6,609 trillion cubic feet, and world technically recoverable gas resources are roughly 16,000 trillion cubic feet, largely excluding shale gas. Thus, adding the identified shale gas resources to other gas resources increases total world technically recoverable gas resources by over 40 percent to 22,600 trillion cubic feet.

Global consumption of natural gas was estimated to be about 100 Tcf in 2009 and is projected to increase to about 156 Tcf by 2035.

Do read the summary and the report (51 mb) to get an idea about the methodology for estimating shale gas resources. 

For India, data adequate enough to generate estimates of shale gas was available from 4 sedimentary basins. These were from the Cambay Basin, the Krishna Godavari Basin, the Cauvery Basin and the Damodar Valley Basin. These basins are estimated to contain about 63 Tcf of recoverable shale gas.

There are many other sedimentary basins which remain relatively unexplored for their shale gas potential.

Image below shows the assessed sedimentary basins along with other basins which are though to contain shale gas but for which adequate data is not yet available.

Below is a basin-wise breakdown of the shale gas estimates along with graphics of the basin structure and prospective blocks within the basins.

Cambay Basin:

This is an elongate intra-cratonic rift basin of late Cretaceous-Cenozoic age situated in western Indian state of Gujarat. The formation of interest is the Palaeocene-Eocene Cambay black shale. Technically recoverable shale gas is estimated to be about 20 Tcf.

Krishna Godavari Basin:

A Late Permian to Tertiary age basin in eastern India consisting of a series of horst and graben. The prospective formation is the Permian age Kommugudem shale. Technically recoverable resources are estimated to be about 27 Tcf.

Cauvery Basin:

The Cretaceous-Cenozoic Cauvery basin in south eastern India is another basin with horst and graben structures and prospective shales. The formations of interest are the early Cretaceous Andimadam Formation and the Sattapadi shale. Technically recoverable resources are about 9 Tcf.

Damodar Valley Basin:

This basin is part of the "Gondwana" basins of India characterized by their mostly non-marine sedimentary fill and narrow graben structures. Although filled with mostly Late Permian to Triassic terrestrial sediment, there is a significant thickness of a marine shale known as the Barren measures, so called as it is barren of coal. The technically recoverable resources from this shale are estimated to be 7 Tcf.

Below is a table summarizing the geological and shale gas attributes of the basins of interest.

As the report makes clear, these are initial estimates (not proven reserves) based on available data on shale formations from basins that already have seen substantial exploration for oil and conventional natural gas. As more focused exploration for shale gas continues from these basins and as more basins are explored these estimates of shale gas resources will likely change.

Update [ May 17 ]: [ Just a quick clarification on terminology. In the table above three estimates of gas are given. GIP is Gas in Place and it refers to the total gas content of the shale formation as estimated from geological attributes. Risked GIP is a fraction of GIP after applying certain success factors i.e. using information available of the productivity of the formation and other factors that might limit its development. Finally, Risked Recoverable is the fraction of Risked GIP that can be technically recovered. That is the amount - 63 Tcf- I have used in this post.

There are reports in the media claiming for example that shale gas in India has been estimated to be about 600 - 2000 Tcf. These refer to Gas in Place estimates and are comparable to the GIP estimates in the EIA report. They are sometimes improperly referred to as reserves (amount of resource that can be exploited economically at any given time). These large amounts mentioned in some media reports are not proven reserves but an estimate of the total gas content stored in the formation. Out of that only a fraction will be technically recoverable.]

India produced about 1.4 Tcf in 2009 and consumed about 1.8 Tcf.  These shale gas resources as they are realized will add significantly to India's hydrocarbon reserves.

Some broad issues to think about:

1) Will a shale gas policy allowing for exploration and exploitation be put in place quickly?

2) Will concerns about leakage of fracking fluids and methane into groundwater be addressed thoroughly and transparently.

3) Besides contamination of groundwater, there is also a concern of water usage. Wells drilled into shale require large amounts of water to be pumped in during the process of fracking i.e hydraulic fracturing of the rock.  How will conflicts of water use with farmers and affected communities be resolved?

Update Jan 5 2012: In a recent assessment (USGS Fact Sheet India Shale Gas 2011) of the Cambay, Krishna Godavari and Cauvery provinces of India, the United States Geological Survey has downgraded shale gas resources from 63 tcf estimated by the Energy Information Agency to 6.1 tcf. Downgrading shale gas resource estimates is not unique to India. Revisions are going on all over the world and is probably due to the observation that production from shale gas wells falls significantly after the first year or so of extraction. So their performance over the long term may not be able to match up the initial surge.  For example, the prolific Marcellus Shale from eastern U.S initially estimated to contain 410 tcf of gas again estimated by the EIA has been downgraded to contain about 84 tcf of technically recoverable gas by the USGS.

The India revision is analogue data and was developed using estimates of ultimate well recovery and success ratios from various U.S. data. This figure might itself be open for revision as more focused exploration is undertaken in these various basins.

Indian Sedimentary Basins And Shale Gas

Over the last few months, several articles and papers have emphasized the potential role shale gas will play in India's hunt for energy. Shale gas is natural gas trapped in fine grained sediment.

Update May 18 2011: [ See post India Basin-Wise Shale Gas Estimates for estimates of shale gas from various Indian sedimentary basins.] 

These articles did not have any graphics so I am putting up a map of Indian sedimentary basins and a graphic depicting shale gas geological reservoirs.

Indian Sedimentary Basins

 Source: Geotimes

The basins of interest in terms of shale gas potential are the mostly marine Mesozoic and Cenozoic basins in Rajasthan and Gujarath and the Cenozoic basins of Assam. The Gondwana basins of central and eastern India are continental interior rift basins and are coal rich and have associated coal bed methane which if tapped could also play an important role in India's energy mix.

Shale Gas Geological Reservoirs

Unlike gas reservoirs in coarser materials like sands, natural gas in shale is trapped in micro pores which may not be connected to each other i.e. they have low permeability and the gas is quite difficult to extract.

India's conventional natural gas reserves are growing with new discoveries mostly along the east coast Krishna Godavari offshore basins. Early estimates of these gas resources if proved correct may more than double in terms of energy equivalence India's proven reserves of about 5.6 billion barrels of oil. Unconventional resources like shale gas have the potential of adding substantially  more to these resources. Currently natural gas makes up a small portion of India's energy consumption pie (see fig on left) and the chance to move towards a cleaner emissions profile by substantially displacing coal in power generation (coal makes up about 70% of electricity generation) and eventually as fuel for transport makes these unconventional sources a critical energy resource of the future.

I don't know how much shale gas resources India has because there has not been a systematic evaluation of shale gas. India's current energy policy prohibits exploitation of shale gas and coal-bed methane. The sooner that policy changes the better for energy starved India.  

[Update Sept 3:] As a reader pointed out in the comments there is recent movement from the government on the exploitation of shale gas and coal bed methane. See this article. A policy on shale gas is likely to be out by next year, while the government has already auctioned of several blocks for exploration of CBM from various basins.

Still, there is one aspect of exploiting these resources that has not been touched upon by any of the articles I have come across and that is the environmental costs of extracting shale gas. Since this gas is locked up in impermeable layers one of the common methods of extracting it is by hydraulic fracturing of the rock. This involves injecting the shale with fluids and gels mixed with particulates like sand to keep the induced fractures open and enable migration of the gas along open fractures.

A new film "Gasland" discussed on Science Friday last month looks at some of the problems of hydraulic fracturing or "fracking" of the Marcellus shale that underlies large parts of Pennsylvania, New York and Ohio and West Virginia.  Chemicals used in the injecting fluid has been reported to contaminate groundwater in Pennsylvania. At least according to the film, the energy companies have been less than forthright about the chemical composition of the injecting fluids which the film claims includes carcinogens and neurotoxins.

All this should send warning signals about the way and means by which India goes about exploiting these shale gas resources.  Groundwater is as important a resource for India's economic development as is natural gas. Almost all drinking water needs in rural areas are met by groundwater. A significant majority, about 2/3, of arable area in India is irrigated by groundwater.  Contamination of large portions of the overlying aquifer will be nothing short of a catastrophe for farmers who have no other water supply but groundwater.

The exploitation of coal bed methane offers another avenue for social conflict. The Gondwana basins which are coal rich are forested regions and home to many tribal communities. There has been a long history in India of the government and private mineral companies riding roughshod over tribal rights. The current violent insurgency that is taking place along tribal regions of Chattisgarh, Maharashtra and Jharkhand has its roots in the rampant exploitation and callous indifference shown by the state and private companies towards tribal communities.

So, shale gas and coal bed methane offer a significantly large energy source but also open up the possibility of more environmental and social disruption.

Update May 18 2011: For latest estimates of shale gas see - India Basin-Wise Shale Gas Estimates.