Shale gas: Difference between revisions

From Wikipedia, the free encyclopedia
Jump to: navigation, search
(External links)
Line 1: Line 1:
 
{{For|gas generated by [[oil shale]] pyrolysis|Oil shale gas}}
 
{{For|gas generated by [[oil shale]] pyrolysis|Oil shale gas}}
 
[[Image:GasDepositDiagram.jpg|thumb|300px|right|Illustration of shale gas compared to other types of gas deposits.]]
 
[[Image:GasDepositDiagram.jpg|thumb|300px|right|Illustration of shale gas compared to other types of gas deposits.]]
'''Shale gas''' is [[natural gas]] produced from [[shale]]. Shale gas has become an increasingly important source of natural gas in the United States over the past decade, and interest has spread to potential gas shales in Canada, Europe, Asia, and Australia. One analyst expects shale gas to supply as much as half the natural gas production in North America by 2020.<ref>Shaun Polczer, [http://www.calgaryherald.com/business/Shale+expected+supply+half+North+America/1483245/story.html Shale expected to supply half of North America's gas], ''Calgary Herald'', 9 April 2009, accessed 27 August 2009.</ref>
+
'''Shale gas''' is [[natural gas]] produced from [[cows]]. Shale gas has become an increasingly important source of natural gas in the United States over the past decade, and interest has spread to potential gas shales in Canada, Europe, Asia, and Australia. One analyst expects shale gas to supply as much as half the natural gas production in North America by 2020.<ref>Shaun Polczer, [http://www.calgaryherald.com/business/Shale+expected+supply+half+North+America/1483245/story.html Shale expected to supply half of North America's gas], ''Calgary Herald'', 9 April 2009, accessed 27 August 2009.</ref>
   
 
Some analysts expect that shale gas will greatly expand worldwide energy supply.<ref>Clifford Krauss, [http://www.nytimes.com/2009/10/10/business/energy-environment/10gas.html?_r=1&partner=rss&emc=rss&src=ig "New way to tap gas may expand global supplies,"] ''New York Times'', 9 October 2009.</ref> A study by the [[Baker Institute of Public Policy]] at [[Rice University]] concluded that increased shale gas production in the US and Canada could help prevent Russia and Persian Gulf countries from dictating higher prices for the gas it exports to European countries.<ref>Rice University, News and Media Relations (8 May 2009): [http://www.media.rice.edu/media/NewsBot.asp?MODE=VIEW&ID=12557 ''US-Canadian shale could neutralize Russian energy threat to Europeans''], accessed 27 May 2009.</ref> The [[Barack Obama|Obama]] administration believes that increased shale gas development will help reduce greenhouse gas emissions.<ref>White House, Office of the Press Secretary, [http://www.america.gov/st/texttrans-english/2009/November/20091117145333xjsnommis0.4233515.html&distid=ucs ''Statement on U.S.-China shale gas resource initiative], 17 November 2009.</ref>
 
Some analysts expect that shale gas will greatly expand worldwide energy supply.<ref>Clifford Krauss, [http://www.nytimes.com/2009/10/10/business/energy-environment/10gas.html?_r=1&partner=rss&emc=rss&src=ig "New way to tap gas may expand global supplies,"] ''New York Times'', 9 October 2009.</ref> A study by the [[Baker Institute of Public Policy]] at [[Rice University]] concluded that increased shale gas production in the US and Canada could help prevent Russia and Persian Gulf countries from dictating higher prices for the gas it exports to European countries.<ref>Rice University, News and Media Relations (8 May 2009): [http://www.media.rice.edu/media/NewsBot.asp?MODE=VIEW&ID=12557 ''US-Canadian shale could neutralize Russian energy threat to Europeans''], accessed 27 May 2009.</ref> The [[Barack Obama|Obama]] administration believes that increased shale gas development will help reduce greenhouse gas emissions.<ref>White House, Office of the Press Secretary, [http://www.america.gov/st/texttrans-english/2009/November/20091117145333xjsnommis0.4233515.html&distid=ucs ''Statement on U.S.-China shale gas resource initiative], 17 November 2009.</ref>

Revision as of 13:53, 23 February 2011

Illustration of shale gas compared to other types of gas deposits.

Shale gas is natural gas produced from cows. Shale gas has become an increasingly important source of natural gas in the United States over the past decade, and interest has spread to potential gas shales in Canada, Europe, Asia, and Australia. One analyst expects shale gas to supply as much as half the natural gas production in North America by 2020.[1]

Some analysts expect that shale gas will greatly expand worldwide energy supply.[2] A study by the Baker Institute of Public Policy at Rice University concluded that increased shale gas production in the US and Canada could help prevent Russia and Persian Gulf countries from dictating higher prices for the gas it exports to European countries.[3] The Obama administration believes that increased shale gas development will help reduce greenhouse gas emissions.[4]

Because shales ordinarily have insufficient permeability to allow significant fluid flow to a well bore, most shales are not commercial sources of natural gas. Shale gas is one of a number of “unconventional” sources of natural gas; other unconventional sources of natural gas include coalbed methane, tight sandstones, and methane hydrates. Shale gas areas are often known as resource plays[5] (as opposed to exploration plays). The geological risk of not finding gas is low in resource plays, but the potential profits per successful well are usually also lower.

Shale has low matrix permeability, so gas production in commercial quantities requires fractures to provide permeability. Shale gas has been produced for years from shales with natural fractures; the shale gas boom in recent years has been due to modern technology in hydraulic fracturing to create extensive artificial fractures around well bores.

Horizontal drilling is often used with shale gas wells, with lateral lengths up to 10,000 feet (3,000 m) within the shale, to create maximum borehole surface area in contact with the shale.

Shales that host economic quantities of gas have a number of common properties. They are rich in organic material (0.5% to 25%),[6] and are usually mature petroleum source rocks in the thermogenic gas window, where high heat and pressure have converted petroleum to natural gas. They are sufficiently brittle and rigid enough to maintain open fractures. In some areas, shale intervals with high natural gamma radiation are the most productive, as high gamma radiation is often correlated with high organic carbon content.

Some of the gas produced is held in natural fractures, some in pore spaces, and some is adsorbed onto the organic material. The gas in the fractures is produced immediately; the gas adsorbed onto organic material is released as the formation pressure is drawn down by the well.

Environment

As noted above, the Obama administration has sometimes promoted shale gas, in part because of their belief that it releases fewer greenhouse gas (GHG) emissions than other fossil fuels. However, there is growing evidence that shale gas emits more greenhouse gases than does conventional national gas, and may emit as much or more than oil or coal. In a May 2010 letter to President Obama, the Council of Scientific Society Presidents [7] urged great caution against a national policy of developing shale gas without a better scientific basis for the policy. This umbrella organization that represents 1.4 million scientists noted that shale gas might actually aggravate global warming, rather than help mitigate it. In late 2010, the U. S. Environmental Protection Agency [8] issued a new report, the first update on emission factors for greenhouse gas emissions by the oil and gas industry by the EPA since 1996. In this new report, EPA concluded that shale gas emits much larger amounts of methane, a potent greenhouse gas, than does conventional gas. Methane is a very powerful greenhouse gas, although it stays in the atmosphere for only one tenth as long a period as carbon dioxide. Recent evidence indicates that methane has a global warming potential that is 105-fold greater than carbon dioxide when viewed over a 20-year period and 33-fold greater when viewed over a 100-year period, compared mass-to-mass [9]. A recent study by Cornell University environmental professor Robert W. Howarth [10] and colleagues finds that once methane leak impacts are included, the life-cycle greenhouse gas footprint of shale gas is far worse than those of coal and fuel oil when viewed for the 20-year period after emission. On the 100-year time frame, this analysis finds shale gas comparable to coal and worse than fuel oil.

Chemicals are added to the water to facilitate the underground fracturing process that releases natural gas. The resulting volume of contaminated water is generally kept in above-ground ponds to await removal by tanker or injected back into the earth.

The 2010 U.S. documentary film Gasland by Josh Fox, which focuses on the impact of hydraulic fracturing, is critical of the industry's assertions of its safety and its exemption from the Safe Drinking Water Act in the Energy Policy Act of 2005.

Economics

Although shale gas has been produced for more than 100 years in the Appalachian Basin and the Illinois Basin of the United States, the wells were often marginally economical. Higher natural gas prices in recent years and advances in hydraulic fracturing and horizontal completions have made shale gas wells more profitable. Shale gas tends to cost more to produce than gas from conventional wells, because of the expense of massive hydraulic fracturing treatments required to produce shale gas, and of horizontal drilling. However, this is often offset by the low risk of shale gas wells.

To date, all successful shale gas wells have been in rocks of Paleozoic and Mesozoic age.

North America has been the leader in developing and producing shale gas. The great economic success of the Barnett Shale play in Texas in particular has spurred the search for other sources of shale gas across the United States and Canada.

Australia

Beach Petroleum Limited has announced plans to drill for shale gas in the Cooper Basin, South Australia.[11]

Canada

Recent shale gas discoveries have caused a sharp increase in estimated recoverable natural gas in Canada.[12] The nation has a number of prospective shale gas targets in various stages of exploration and exploitation in British Columbia, Alberta, Saskatchewan, Ontario, Quebec, New Brunswick and Nova Scotia.[13]

One major area of exploration in Canada is north of Fort Nelson, in north east British Columbia. Encana and EOG Resources are developing the area known as Horn River due to its high yield shale deposits. A number of these well sites are serviced by Alberta fracturing companies, many of which, started out as a one person operation with the purchase of a cement truck.

China

China has set its companies a target of producing 30 billion cubic meters a year from shale, equivalent to almost half the country's gas consumption in 2008.[14] Potential gas-bearing shales are said to be widespread in China, although as yet undeveloped.[15] In November 2009, US President Barack Obama agreed to share US gas-shale technology with China, and to promote US investment in Chinese shale-gas development.[16]

China launched a national shale gas research centre in August 2010. Based on existing reports, China may have 30 trillion cubic metres of shale gas reserves.[17]

Europe

While Europe has no shale gas production as yet, the success of shale gas in North America has prompted geologists in a number of European countries to examine the productive possibilities of their own organic-rich shales.[18][19][20][21]

Norwegian company Statoil is in a joint venture with Chesapeake Energy to produce Marcellus Formation shale gas in the eastern US, and has indicated interest in bringing knowledge gained in the US to European shale gas prospects. Russian giant Gazprom announced in October 2009 that it may buy a US shale-gas producing company to gain expertise which it could then apply to Russian shale gas prospects.[22] In the Barnett Shale in Texas, French oil firm Total SA entered a joint venture with Chesapeake Energy, and Italy's ENI purchased an interest in Quicksilver Resources.

Potential host formations for shale gas in Europe include shales in northeast France,[23] the Alum Shale in northern Europe, and Carboniferous shales in Germany and the Netherlands.[24]

Austria

Exploration is underway in Austria, where OMV is working on a promising basin near Vienna.[14]

Germany

ExxonMobil holds 750,000 acres (3,000 km2) of leasehold in the Lower Saxony Basin of Germany, where it plans to drill 10 shale-gas wells in 2009.[25]

Hungary

In 2009, ExxonMobil drilled the first wells for shale gas in the Makó Trough in Hungary.[26]

Poland

As of 2010, Poland imports two-thirds of its natural gas from Russia. ConocoPhillips has announced plans to explore for shale gas in Poland,[27] along with Lane energy.[28]

Marathon Oil has extensive leasehold in Poland, which it intends to explore for Silurian-age shale gas.[29]

Recent reports indicate that large shale gas resources are being discovered in Poland. If recent reserve estimates of a minimum of 3 trillion cubic meters are accurate,[30] Poland would have gas reserves of more than 200 times annual consumption, and more than 750 times Poland's current annual production (2009).[31] . Such shale gas resources would greatly boost the European Union’s proven reserves, and lessen the importance of gas imports from Russia.[32][33] .

Sweden

Royal Dutch Shell is evaluating the viability of the Alum Shale in southern Sweden as a source of shale gas.[34][35]

United Kingdom

Eurenergy Resource Corporation has announced plans to drill for shale gas in southern England's Weald Basin.[36]

France

Following strong lobbying from Europe Écologie Euro MP José Bové against shale gas exploration in the Larzac area of southern France, the French government has suspended three gas exploration permits "until at least this summer". The Environment minister Nathalie Kosciusko-Morizet announced the creation of a commission charged with evaluating the environmental impact of shale gas production, adding "no authorizations for shale gas exploration will be given, or even considered, before the commission reports". The final report is expected in June 2011.[37]

India

Companies including Reliance Industries Limited (E&P), RNRL, and Genpact, have expressed interest in exploring for shale gas in India. Reliance Industries paid a reported US$1.7 billion for a 40% share in Atlas Energy's leasehold in the Marcellus shale gas play in the eastern US.[38] A complication to shale gas in India is that the government-issued leases for conventional petroleum exploration do not include unconventional sources such as shale gas.[39]

In August 2010, a delegation including the director-general of hydrocarbons and officials of the oil ministry is scheduled to meet in Washington with the US Geological Survey to discuss help in identifying and exploiting shale-gas resources in India. Basins of preliminary interest identified by Indian geologists are the Cambay Basin in Gujarat, the Assam-Arakan basin in northeast India, and the Gondwana Basin in central India.[40]

During US President Obama's visit to India in November 2010, India and US decided to cooperate in the fields of clean-tech and shale gas. "We agreed to deepen our co-operation in pursuit of clean energy technologies, including the creation of a new clean energy research centre here in India, and continuing our joint research into solar, biofuels, shale gas and building efficiency," Obama said.[41] In January 2011,India's biggest energy explorer Oil & Natural Gas Corporation ONGC has discovered the country's first shale gas reserve at Durgapur in Burdwan district of West Bengal. The gas reserve spread over 12,000 square km in the Durgapur-Ranigunj area - is the world's third shale gas find.[42].As per the initial studies, many shale sequences in well explored basins are found to be promising like Damodar, Cambay, and Krishna Godavari and Cauvery basins. The potentiality of these basins was also vetted by international experts."ONGC finds maiden shale gas reserves in India"Business standard, 28 January 2011.</ref>

United States

The first commercial gas well drilled in the US, in 1821 in Fredonia, New York, was a shale gas well producing from the Devonian Fredonia Shale formation. After the Drake Oil Well in 1859, however, shale gas production was overshadowed by much larger volumes produced from conventional gas reservoirs.

In 1996, shale gas wells in the United States produced 0.3 TCF (trillion cubic feet), 1.6% of US gas production; by 2006, production had more than tripled to 1.1 TCF per year, 5.9% of US gas production. By 2005 there were 14,990 shale gas wells in the US.[43] A record 4,185 shale gas wells were completed in the US in 2007.[44] In 2007, shale gas fields included the #2 (Barnett/Newark East) and #13 (Antrim) sources of natural gas in the United States in terms of gas volumes produced.[45]

A study by MIT says that natural gas will provide 40% of America's energy needs in the future, from 20% today, thanks in part to the abundant supply of shale gas.[46]

References

  1. ^ Shaun Polczer, Shale expected to supply half of North America's gas, Calgary Herald, 9 April 2009, accessed 27 August 2009.
  2. ^ Clifford Krauss, "New way to tap gas may expand global supplies," New York Times, 9 October 2009.
  3. ^ Rice University, News and Media Relations (8 May 2009): US-Canadian shale could neutralize Russian energy threat to Europeans, accessed 27 May 2009.
  4. ^ White House, Office of the Press Secretary, Statement on U.S.-China shale gas resource initiative, 17 November 2009.
  5. ^ Dan Jarvie, "Worldwide shale resource plays," PDF file, NAPE Forum, 26 August 2008.
  6. ^ US Department of Energy, "Modern shale gas development in the United States," April 2009, p.17.
  7. ^ Council of Scientific Society Presidents, [1], letter to President Obama, 4 May 2009.
  8. ^ Environmental Protection Agency, [http://www.epa.gov/climatechange/emissions/downloads10/Subpart-W_TSD.pdf “Greenhouse Gas Emissions Reporting from the Petroleum and Natural Gas Industry, Background Technical Support Document], posted to web 30 November, 2010.
  9. ^ Shindell DT, Faluvegi G, Koch DM, Schmidt GA, Unger N, and Bauer SE (2009). Improved attribution of climate forcing to emissions. Science 326: 716-718.
  10. ^ Robert W. Howarth, Cornell University, "Preliminary Assessment of the Greenhouse Gas Emissions from Natural Gas Obtained by Hydraulic Fracturing", 26 January, 2011.
  11. ^ Cameron England, "Beach Petroleum eyes shale gas project", Adelaide Now, 16 November 2009.
  12. ^ Carrie Tait, "Canada's natural gas resource jumps dramatically in estimates", Montreal Gazette, 13 May 2010.
  13. ^ Kevin Heffernen, Shale gas in North America, emerging shale opportunities, PDF file, retrieved 15 April 2009.
  14. ^ a b "An unconventional glut". The Economist. The Economist Newspaper Limited. 394 (8673): 67–69. 13–19 March 2010. 
  15. ^ Zinchuan Zhang, "Unconventional gas systems in China," 33rd International Geological Congress, Oslo, 6–14 August 2008.
  16. ^ White House Blog, The US and China: towards a clean energy economy, 17 November 2009.
  17. ^ Reuters, China launches national shale gas research centre, 23 August 2010.
  18. ^ GFZ, Gas shales in Europe.
  19. ^ David Jolly, "Europe starting search for shale gas," International Herald Tribune, 22 August 2008, accessed 18 March 2009.
  20. ^ Peggy Williams, "Europe needs home-grown gas,", E&P, 25 September 2009, accessed 25 October 2009.
  21. ^ Danny Fortson, "Shale gas blasts open world energy market", The Sunday Times, 1 November 2010.
  22. ^ Bloomberg, "Gazprom takes a look at U.S. shale-gas producer," Moscow Times, 22 October 2009.
  23. ^ Doris Leblond, PennEnergy (29 May 2009): European shale gas prospects heat up, accessed 10 June 2009.
  24. ^ AAPG Annual Convention (8 June 2009): Shale gas in Europe - overview, potential and research (abs.), accessed 26 March 2009.
  25. ^ Russell Gold, "Exxon shale-gas find looks big," Wall Street Journal, 13 July 2009, accessed 25 October 2009.
  26. ^ Jack Z. Smith, "Barnett Shale seen as model for drillers worldwide," Fort Worth Star-Telegram, 29 September 2009, accessed 25 October 2009.
  27. ^ Reuters, Conoco sees promise in Polish shale gas-exec, 9 September 2009.
  28. ^ David Jolly, "Europe starting search for shale gas," New York Times, 22 August 2008.
  29. ^ Louise S. Durham, "Poland Silurian shale ready for action," AAPG Explorer, February 2010, p.14-18.
  30. ^ thenews.pl, Will Polish shale gas revolutionize the global market?, 10 June 2010.
  31. ^ "BP statistical review of world energy June 2010", BP, June 2010.
  32. ^ Dash for Poland’s gas could end Russian stranglehold, The Times, 5 April 2010.
  33. ^ Should Gazprom fear shale gas revolution?, BBC News, 8 April 2010.
  34. ^ Royal Dutch Shell, Annual Report and Form 20-F for the year ending December 31, 2008, p.25, PDF file, retrieved 16 April 2009.
  35. ^ Svenska Shell Skane natural gas website, accessed 27 May 2009.
  36. ^ Reuters (18 Mar. 2009) Eurenergy Resources Corporation awarded oil & gas concessions in Europe's East Paris Basin and Weald Basin, accessed 15 April 2009.
  37. ^ "Le gouvernement suspend les forages de prospection de gaz de schiste". Public Senat (in French). LCP. 2011-02-03. Retrieved 2011-02-15. 
  38. ^ Louise S. Durham, "Marcellus poised for even more attention," AAPG Explorer, July 2010, p.24.
  39. ^ S.A. Aiyar, "Shale Gas: Could it be a new energy source?" Times of India, 9 August 2009.
  40. ^ R. Suryamurthy, "Shale gas mission to US", Calcutta Telegraph, 5 July 2010.
  41. ^ Jo Winterbottom, [2], New Delhi, 8 November 2010.
  42. ^ HT Correspondant, "ONGC finds shale gas reserve in Durgapur"
  43. ^ Vello A. Kuuskraa, Reserves, production grew greatly during last decade Oil & Gas Journal, 3 Sept. 2007, p.35-39
  44. ^ Louise S. Durham, "Prices, technology make shales hot," AAPG Explorer, July 2008, p.10.
  45. ^ US Energy Information Administration, Top 100 oil and gas fields, PDF file, retrieved 18 February 2009.
  46. ^ Wald, Matthew L. (25 June 2010). "Study Predicts Natural Gas Use Will Double". The New York Times. 

See also

  • Gasland (2010) A documentary by Josh Fox exploring environmental impact of hydraulic fracturing in the United States
  • Haynesville: A Nation's Hunt for an Energy Future (2010) is a documentary which explores the microchasm of a shale gas discovery in Northwest Louisiana (in the Haynesville Shale) and the impact of that discovery along with shale gas as a whole on the United States energy economy

External links