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| Map of 48 major shale gas basins in 32 countries. Source: EIA. Click to enlarge. |
Initial assessments of 48 shale gas basins containing almost 70 shale gas formations in 32 countries suggest that shale gas resources, which have recently provided a major boost to US natural gas production, are also available in other world regions. A new EIA-sponsored study by Advanced Resources International, Inc. reports initial assessments of 5,760 trillion cubic feet (Tcf) of technically recoverable shale gas resources in 32 foreign countries.
Adding the estimated US shale gas technically recoverable resources (862 Tcf) to the assessments in the study gives a total of 6,622 Tcf. For comparison, most current estimates of world technically recoverable natural gas resources include few if any of the resources assessed in this study and total about 16,000 Tcf.
Adding identified shale gas resources to current estimates of other gas resources increases total world technically recoverable resources by over 40 percent, to more than 22,000 trillion cubic feet.
—EIA Administrator Richard Newell.
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| Estimated recoverable shale gas resources by country. Data: EIA. Click to enlarge. |
The technically recoverable resource estimate for shale gas in the report is established by multiplying the risked gas in-place by a shale gas recovery factor, which incorporates a number of geological inputs and analogs that are appropriate to each shale gas basin and formation. The risked gas in-place estimate is derived by first estimating the amount of ‘gas in-place’ resource for a prospective area within the basin, and then de-rating that gas in-place by factors that account for the current level of knowledge of the resource and the
capability of the technology to eventually tap into the resource.
The basic recovery factors used in this report generally ranged from 20% to 30%, with some
outliers of 15% and 35% being applied in exceptional cases. The consultant selected the
recovery factor based on prior experience in how production occurs, on average, given a range of
factors including mineralogy, geologic complexity, and a number of other factors that affect the
response of the geologic formation to the application of best practice shale gas recovery technology.
Estimates of shale gas resources in other parts of the world are highly uncertain, the EIA notes. The practicality of using such resources has only recently become apparent, and many countries are just now beginning to understand how to conduct assessments of how much shale gas they may have. Nonetheless, the aggregate estimate is probably quite conservative, the EIA says, since the study excluded several major types of potential shale gas resources:
- Nations outside the 32 countries studied. These include Russia and the Middle East, which have very large resources of conventional gas.
- Some shale basins in the countries studied. In many cases, no estimates are possible yet for these basins.
- Offshore resources.
Of the countries covered in the EIA-sponsored study, World Shale Gas Resources: An Initial Assessment of 14 Regions Outside the United States, two groups may find shale gas development most attractive.
The first is those countries that currently depend heavily on natural gas imports but that also have significant shale gas resources. These include France, Poland, Turkey, Ukraine, South Africa, Morocco, and Chile. The second group is those countries that already produce substantial amounts of natural gas and also have large shale resources. In addition to the United States, this group includes Canada, Mexico, China, Australia, Libya, Algeria, Argentina, and Brazil.
In terms of recoverable shale gas resources, China takes the top spot, with an estimated 1,275 Tcf. The US is second, with 862 Tcf, followed by Argentina with 774 Tcf and Mexico with 681 Tcf.
Background. The use of horizontal drilling in conjunction with hydraulic fracturing has greatly expanded the ability of producers to profitably produce natural gas from low permeability geologic formations, particularly shale formations. In 2010, US shale gas production reached 4.87 Tcf (23% of total US natural gas production), compared with 0.39 Tcf in 2000. This shows both the rapid growth and absolute importance of the shale gas resource to the United States. Rising production from shale gas resources has been credited with both lower natural gas prices and declining dependence on imported natural gas.
The growing importance of US shale gas resources is also reflected in EIA’s Annual Energy Outlook 2011 (AEO2011) energy projections, with technically recoverable US shale gas resources now estimated at 862 trillion cubic feet. Given a total natural gas resource base of 2,543 trillion cubic feet in the AEO2011 Reference case, shale gas resources constitute 34% of the domestic natural gas resource base represented in the AEO2011 projections and 50% of lower 48 onshore resources. As a result, shale gas is the largest contributor to the projected growth in production, and by 2035 shale gas production accounts for 46% of US natural gas production.
The successful investment of capital and diffusion of shale gas technologies has continued into Canadian shales as well. In response, several other countries have expressed interest in developing their own nascent shale gas resource base, which has lead to questions regarding the broader implications of shale gas for international natural gas markets.
As is often the case with resource development, the EIA notes, shale gas production also has raised local environmental concerns, largely centering on the amount of water used in the fracturing process and the need to handle, recycle, and treat fracturing fluids in a manner that addresses the risk of spills that can potentially affect water quality.
(A hat-tip to John!)
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