Saturday, April 30, 2011

Global shale gas reserves

Shale gas is fast emerging as the next big global energy source. Marginal Revolution points to this graphic of global shale gas reserves from an assessment of 48 shale gas basins in 32 countries made by the US Energy Information Agency. The EIA estimates that over 6,600 Tcf of shale gas resources are estimated to be technically recoverable.

To lend some perspective, 1,000 Tcf of natural gas contains the equivalent energy to 166 billion barrels of oil. Note that India does not have anything to cheer from this source too, atleast from this set of data. It is possible that exploration for shale gas is at its nascent stages in Asia and Africa.

The only real issue with shale gas is whether its costs - by way of hydraulic fracking causing pollution of aquifers and methane leakages from shale wells - exceed the benefits arising from lower carbon releases. However, the final verdict may not come anytime soon. Over the next few years, there will surely be significant improvements in technologies aimed at curbing pollution.

Update 1 (7/10/2011)

FT has this article on the potential of shale gas, especially in the north eastern rust belt in the US. Natural gas is much cheaper in the US at about $3.60 per million British thermal units compared with about $8 in the UK and $16 in Japan. More importantly, the US gas price works out at the equivalent of $22 a barrel, about one-fifth of the Brent crude price of more than $100.

Update 2 (7/12/2011)

WSJ has a story on concerns about water consumption associated with hydraulic fracturing, or fracking, in parched South Texas. Energy companies blast rocks far below the surface with enormous amounts of water-about six million gallons at a time-mixed with sand and chemicals at high pressure in order to release oil and natural gas, sometimes depleting local water supplies.

It takes 407 million gallons to irrigate 640 acres and grow about $200,000 worth of corn on the arid land. The same amount of water, he says, could be used to frack enough wells to generate $2.5 billion worth of oil.

To date, criticism of fracking has focused mainly on concerns that the chemicals energy companies are mixing with the water could contaminate underground aquifers. Oil industry officials regard that issue as manageable. The biggest challenge to future development, they say, is simply getting access to sufficient water.

Update 3 (24/2/2012)

A report by the US EIA of 48 shale gas basins in 32 countries estimates "technically recoverable" global shale gas resources at 6,600tn cubic feet, roughly equal to today’s proved reserves. Martin Wolf writes on the benefits of natural gas

Gas emits slightly more than half as much carbon dioxide as coal and 70 per cent as much as oil, per unit of energy output. Emissions from gas of carbon monoxide are a fifth as much as from coal. Emissions of sulphur dioxide and particulates are negligible. In any plausible scenario for managing emissions of greenhouse gases, natural gas will have to substitute for other fuels, though development of cheap carbon capture and storage would also strengthen the case for coal.

He argues that the wisdom of proceeding rapidly with this technology globally will depend on several considerations:

First, the local opportunity costs of water; second, the abilities and reliability of the operators; third, the capacity of the regulators; fourth, the benefits of any extra gas, compared with those of alternative fuels (or conservation), including for security; and, fifth, better knowledge of the impact of the technologies.
Update 4 (23/4/2012)

Good FT article on shale gas is available here. 

Update 5 (8/5/2012)

A Cornell study finds that the carbon emissions footprint from shale gas is much higher than conventional fuels.
Natural gas is composed largely of methane, and 3.6% to 7.9% of the methane from shale-gas production escapes to the atmosphere in venting and leaks over the life-time of a well. These methane emissions are at least 30% more than and perhaps more than twice as great as those from conventional gas...

The footprint for shale gas is greater than that for conventional gas or oil when viewed on any time horizon, but particularly so over 20years. Compared to coal, the footprint of shale gas is at least 20% greater and perhaps more than twice as great on the 20-year horizon and is comparable when compared over 100 years.

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