Tar sands

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Oil sands, tar sands or, more technically, bituminous sands, are a type of "unconventional" oil/petroleum deposit. The oil sands are loose sand or partially consolidated sandstone containing naturally occurring mixtures of sand, clay, and water, saturated with a dense and extremely viscous form of petroleum technically referred to as bitumen (or colloquially tar due to its similar appearance, odor and color). Natural bitumen deposits are reported in many countries, but in particular are found in extremely large quantities in Canada.[1][2] Other large reserves are located in Kazakhstan and Russia. Total natural bitumen reserves are estimated at 249.67 billion barrels (39.694×109 m3) globally, of which 176.8 billion barrels (28.11×109 m3), or 70.8%, are in Canada.[1]

Oil sands reserves have only recently been considered to be part of the world's oil reserves, as higher oil prices and new technology enable profitable extraction and processing. Oil produced from bitumen sands is often referred to as unconventional oil or crude bitumen, to distinguish it from liquid hydrocarbons produced from traditional oil wells.[3]

Greenhouse gas emissions

Making liquid fuels from oil sands requires energy for steam injection and refining. This process generates 12 percent higher the amount of greenhouse gases per barrel of final product as the "production" of conventional oil.[4]

According to Oil Change International, emissions from tar sands extraction and upgrading are between 3.2 and 4.5 times higher than the equivalent emissions from conventional oil produced in North America. On a lifecycle basis, OCI states the average gallon of tar sands bitumen derived fuel has between 14 and 37 percent more greenhouse gas emissions than the average gallon of fuel from conventional oil.[5]

In January 2013 Oil Change International released a study, "Petroleum Coke: The Coal Hiding in the Tar Sands," that found refining Alberta's tar sands will create 5 billion tons of petroleum coke, or petcoke, used by power plants, aluminum factories, and steel mills. Compared with coal, petcoke is cheaper and releases five to ten percent more carbon dioxide when burned. The report stated that 15 percent to 30 percent of a barrel of oil sands bitumen can end up as petcoke, while a lighter crude would have less than 2 percent, yet the increased pet coke has not been accounted for in calculating the overall carbon footprint of tar sands for projects like Keystone XL Pipeline. Much of the U.S. supply of petcoke is exported.

Definition

The crude bitumen contained in Alberta's tar sands is described by Canadian authorities as "petroleum that exists in the semi-solid or solid phase in natural deposits. Bitumen is a thick, sticky form of hydrocarbon, so heavy and viscous (thick) that it will not flow unless heated or diluted with lighter hydrocarbons. At room temperature, it is much like cold molasses".[6] The World Energy Council (WEC) defines natural bitumen as "oil having a viscosity greater than 10,000 centipoises under reservoir conditions and an API gravity of less than 10° API".[1] The Orinoco Belt in Venezuela is sometimes described as oil sands, but these deposits are non-bituminous, falling instead into the category of heavy crude oil due to their lower viscosity.[7] Natural bitumen and extra-heavy oil differ in the degree by which they have been degraded from the original conventional oils by bacteria and erosion. According to the WEC, extra-heavy oil has "a gravity of less than 10° API and a reservoir viscosity of no more than 10,000 API".[1]

Energy return

The average "energy returned on investment," or EROI, for conventional oil is roughly 25:1 (25 units of oil-based energy obtained for every one unit of other energy invested to extract it.) Geologist David Hughes calculated that the tar sands retrieved by surface mining has an EROI of about 5:1, and as low as 2.9:1 for tar sands retrieved from deeper beneath the earth. Hughes's figures include the energy it takes to mine bitumen as well as to upgrade it to synthetic oil that can be put into a refinery. It also includes the liquefied natural gas used to turn it into dilbit (diluted bitumen) so it can flow through pipelines, but does not include transport from the pipelines. Travis Davies, media manager at the Canadian Association of Petroleum Producers, disputes the calculations and said oil sands create 6 to 10 energy units for each energy unit used.[8]

Projects

  • Alberta's tar sands
  • Keystone XL Pipeline
  • Book Cliffs Mine
  • Asphalt Ridge, Utah - In November 2012 MCW Enterprises Ltd., a Canada-based corporation, said it had received all necessary permits to streamline tar sands extraction at its Asphalt Ridge plant located in Vernal, Utah starting in December. MCW Enterprises Ltd. owns MCW Oil Sands Recovery LLC as a wholly owned subsidiary. The company's CEO, R. Gerald Bailey is the former President of Exxon Arabian Gulf.[9] In January 2014, Kellogg Brown & Root was awarded a project and construction management contract for the project.[10]
  • Rocky Mountains - In 2012, the U.S. Department of the Interior said it was set to authorize 1,250 square miles of public land for commercial leasing of oil shale and tar sands in Colorado, Utah, and Wyoming. The land is a third of the what former President George W. Bush planned to offer, and the new administration said it was taking wilderness-quality lands off the table. Some estimates put the potential oil in the region at 1 trillion barrels — but environmental groups question the estimates, and say extraction would involve ripping up public lands and depleting scarce sources of water, including the Colorado River.[11]

Health effects

A 2013 study published in the Proceedings of the National Academy of Sciences journal found that found levels of polycyclic aromatic hydrocarbons (PAHs), a toxic carcinogen, have risen roughly at the same pace as oil sands development in six nearby lakes in Alberta. The researchers attributed the higher PAH levels to “multiple environmental factors,” including climate change, as well as nearby oil-sands development. It’s “well established” that some PAHs are carcinogenic, according to the American Agency for Toxic Substances and Disease Registry. Some types of PAHs have been linked to infertility, immune disorders, and fish mutation.[12]

Articles and Resources

Sources

  1. 1.0 1.1 1.2 1.3 (2010) "Natural Bitumen and Extra-Heavy Oil", Survey of energy resources (PDF), 22, World Energy Council, 123–140. ISBN 0-946121-26-5. 
  2. "Alberta's Oil Sands: Opportunity, Balance" (PDF) (March 2008). Government of Alberta. Retrieved on 13 May 2008. 
  3. Barbara Lewis, David Ljunggren and Jeffrey Jones. "Canada's Tar Sands Battle With Europe", huffington post. 
  4. Barbara Lewis, David Ljunggren and Jeffrey Jones. "Canada's Tar Sands Battle With Europe", huffington post. 
  5. Elizabeth Bast, "Petroleum Coke: The Coal Hiding in the Tar Sands," Oil Change International, Jan 17, 2013.
  6. "Glossary" (2010). Canada's Oil Sands. Retrieved on 23 August 2010. 
  7. Dusseault, M. B. (12-14). "Comparing Venezuelan and Canadian heavy oil and tar sands". Proceedings of Petroleum Society's Canadian International Conference 2001-061: 20p. 
  8. Rachel Nuwer, "Oil Sands Mining Uses Up Almost as Much Energy as It Produces: Thanks to high global oil prices, industry can afford the large amount of energy needed to extract the oil and turn it into a usable fuel," Inside Climate News, Feb 19, 2013.
  9. Steve Horn, "Second US Tar Sands Mine, Owned by Former ExxonMobil and Chevron Exec., Approved in Utah," DeSmog Blog, Nov. 21, 2012.
  10. " Contract awarded for first US oil sands mine: KBR to construct and manage east Utah project," tce today, Jan 21, 2014.
  11. "US limits oil-shale development in Rocky Mountains," AP, Nov. 9, 2012.
  12. "Oil sands development polluting Alberta lakes: study," The Globe and Mail, Jan. 7, 2013.

Related SourceWatch Articles

External links

Wikipedia also has an article on Tar sands. This article may use content from the Wikipedia article under the terms of the GFDL.