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Unconventional oil

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Unconventional oil is petroleum produced or extracted using techniques other than the traditional oil well method. Currently, unconventional oil production is less efficient and some types have a larger environmental impact relative to conventional oil production. According to the International Energy Agency's Oil Market Report unconventional oil includes the following sources:

These unconventional sources of oil may be increasingly relied upon as motor fuel for transportation when conventional oil becomes "economically non-viable" due to depletion. Conventional sources of oil are currently preferred because they provide a much higher ratio of extracted energy over energy used in extraction and refining processes. Technology, such as using steam injection in oil sands deposits, is being developed to increase the efficiency of unconventional oil production.

Extra heavy oil and oil sands

Main articles: Heavy crude oil, Oil sands, and cold heavy oil production with sand

Extra heavy oils are extremely viscous, with a consistency ranging from that of heavy molasses to a solid at room temperature. Heavy crude oils have a density (specific gravity) approaching or even exceeding that of water. As a result, they cannot be produced, transported, and refined by conventional methods. Heavy crude oils usually contain high concentrations of sulfur and several metals, particularly nickel and vanadium. These properties make them difficult to pump out of the ground or through a pipeline and interfere with refining. These properties also present serious environmental challenges to the growth of heavy oil production and use. Venezuela's Orinoco heavy oil belt is the best known example of this kind of unconventional reserve. Estimated reserves: 1.2 trillion barrels (190 km3).[2]

Heavy oils and oil sands occur world-wide, but the two most important deposits are the Athabasca Oil Sands in Alberta, Canada and the Orinoco extra heavy oil deposit in Venezuela. The hydrocarbon content of these deposits is called bitumen, on which the fuel Orimulsion is based. The Venezuelan extra heavy oil deposits differs from oil sands in that they flow more readily at ambient temperature and could be produced by cold-flow techniques, but the recovery rates would be less than the Canadian techniques (about 8% versus up to 90% for surface mining and 60% for steam assisted gravity drainage).

It is estimated by oil companies that the Athabasca and Orinoco sites (both of similar size) have as much as two-thirds of total global oil deposits. However, they have only recently been considered proven reserves of oil as cost to extract the oil declined to less than $15 per barrel at the Suncor and Syncrude mines while world oil prices rose to over $140 during the oil price increases since 2003.

Extracting a significant percentage of world oil production from these fossil fuels will be difficult since the extraction process takes a great deal of capital, manpower and land. Another major constraint is energy for heat and electricity generation, currently coming from natural gas, itself in short supply. A bitumen upgrader is under construction at Fort McMurray, Alberta to supply syngas to replace natural gas, and there are even proposals to build nuclear reactors using fuel from nearby Uranium City, Saskatchewan to supply steam and electricity.

At rate of production projected for 2015, about 3 million barrels per day (480,000 m3/d), the Athabasca oil sands reserves would last over 400 years.[3] The oil extraction process requires either strip mining or in-situ processing, steam and caustic soda (NaOH). The process is more energy intensive than conventional oil and thus more expensive.

Tight Sands "Natural gas from tight sands is conventional natural gas extracted from unconventional reservoirs." [4] Tight sands are characterized by their low permeability because of compaction, the nature of the fine sediments, or pore space infilling. The flow rates of tight sands are uneconomical and it takes special technologies to produce this unconventional resource. New research processes and help from the US Department of Energy have enhanced the advances in technology used to retrieve and develop unconventional gas.

Keeping up with demand of oil and gas is very difficult, and companies are now embracing alternative methods of oil and gas production, such as unconventional resources. The actual definition of unconventional resources is "natural gas resources which require greater than industry-standard levels of technology or investment to harvest" [5] As little as 10–12 years ago, unconventional resources were overlooked by natural gas companies. This is now a very important resource for natural gas companies today.

Oil shale

Main articles: Oil shale, Shale oil extraction, and Oil shale reserves

Oil shale is an organic-rich fine-grained sedimentary rock containing significant amounts of kerogen (a solid mixture of organic chemical compounds) from which technology can extract liquid hydrocarbons (shale oil) and combustible oil shale gas. The kerogen in oil shale can be converted to shale oil through the chemical processes of pyrolysis, hydrogenation, or thermal dissolution.[6][7]. The temperature when perceptible decomposition of oil shale occurs depends on the time-scale of the pyrolysis; in the above ground retorting process the perceptible decomposition occurs at 300 °C (570 °F), but proceeds more rapidly and completely at higher temperatures. The rate of decomposition is the highest at a temperature of 480 °C (900 °F) to 520 °C (970 °F). The ratio of shale gas to shale oil depends of retorting temperature and as a rule increases by the rise of temperature.[6] For the modern in-situ process, which might take several months of heating, decomposition may conducted as low as 250 °C (480 °F). Depending the exact propeties of oil shale and the exact processing technology, the retorting process may be water and energy extensives. Oil shale has also been burnt directly as a low-grade fuel.[8][9]

Estimates of global deposits range from 2.8 trillion to 3.3 trillion barrels (450×109 to 520×109 m3) of recoverable oil.[8][10][11][12] There are around 600 known oil shale deposits around the world, including major deposits in the United States of America.[13] Although oil shale deposits occur in many countries, only 33 countries possess known deposits of possible economic value.[14][15] The largest deposits in the world occur in the United States in the Green River Formation, which covers portions of Colorado, Utah, and Wyoming; about 70% of this resource lies on land owned or managed by the United States federal government.[16] Deposits in the United States constitute 62% of world resources; together, the United States, Russia and Brazil account for 86% of the world's resources in terms of shale-oil content.[14] These figures remain tentative, with exploration or analysis of several deposits still outstanding.[8][9] Well-explored deposits, potentially possessing economic value, include the Green River deposits in the western United States, the Tertiary deposits in Queensland, Australia, deposits in Sweden and Estonia, the El-Lajjun deposit in Jordan, and deposits in France, Germany, Brazil, Morocco, China, southern Mongolia and Russia. These deposits have given rise to expectations of yielding at least 40 liters of shale oil per tonne of shale, using the Fischer Assay method.[9][17]

The various attempts to develop oil shale deposits have succeeded only when the cost of shale-oil production in a given region comes in below the price of crude oil or its other substitutes.[18] According to a survey conducted by the RAND Corporation, the cost of producing a barrel of oil at a surface retorting complex in the United States (comprising a mine, retorting plant, upgrading plant, supporting utilities, and spent shale reclamation), would range between US$70–95 ($440–600/m3, adjusted to 2005 values).[19] As of 2008, industry uses oil shale for shale oil production in Brazil, China and Estonia. Several additional countries started assessing their reserves or had built experimental production plants.[8] If oil shale could be used to meet a quarter of the current 20 million barrels per day (3,200,000 m3/d) demand, 800 billion barrels (1.3×1011 m3) of recoverable resources would last for more than 400 years.[19]

Biofuels

Biofuels such as biodiesel, ethanol, and straight vegetable oil are also hydrocarbon fuels. There are non-hydrocarbon biofuels as well such as anaerobic hydrogen producers.

Thermal depolymerization

Thermal depolymerization (TDP) has the potential to recover a lot of energy from existing sources of waste such as petroleum coke as well as pre-existing waste deposits. Because energy output varies greatly based on feedstock, it is difficult to estimate potential energy production.

Coal and gas conversion

Using synthetic fuel processes, the conversion of coal and natural gas has the potential to yield great quantities of unconventional oil and/or refined products, albeit at much lower net energy output than the historic average for conventional oil extraction.

The four primary conversion technologies used for the production of unconventional oil and refined products from coal and gas are the indirect conversion processes of the Fischer-Tropsch process and the Mobil Process (also known and Methanol to Gasoline), and the direct conversion processes of the Bergius process and the Karrick process.

Sasol has run a 150,000 barrel per day coal-to-liquids plant based on Fischer Tropsch conversion in South Africa since the 1970s.

Because of the high cost of transporting natural gas, many known but remote fields were not being developed. On-site conversion to liquid fuels are making this energy available under present market conditions. Fischer Tropsch fuels plants converting natural gas to fuel, a process broadly known as gas-to-liquids are operating in Malaysia, South Africa, and Qatar.

Large direct conversion coal to liquids plants are currently under construction, or undergoing start-up in China.

Total global synthetic fuel production capacity exceeds 240,000 BPD, and is expected to grow rapidly in coming years, with multiple new plants currently under construction.

See also

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References

  1. ^ World Energy Outlook 2001: Assessing Today's Supplies to Fuel Tomorrow's Growth (PDF). Organisation for Economic Co-operation and Development/International Energy Agency. 2001. ISBN 9264196587. Retrieved 2009-06-27.
  2. ^ "Environmental Challenges of Heavy Crude Oils". Battelle Memorial Institute. 2003.
  3. ^ Department of Energy, Alberta (2006). "Oil Sands Fact Sheets". Retrieved 2007-04-11. {{cite web}}: Unknown parameter |month= ignored (help)
  4. ^ Centre for Energy
  5. ^ Unconventional Resources
  6. ^ a b Koel, Mihkel (1999). "Estonian oil shale". Oil Shale. A Scientific-Technical Journal (Extra). Estonian Academy Publishers. ISSN 0208-189X. Retrieved 2007-07-21.
  7. ^ Luik, Hans (2009-06-08). Alternative technologies for oil shale liquefaction and upgrading (PDF). International Oil Shale Symposium. Tallinn, Estonia: Tallinn University of Technology. Retrieved 2009-06-09.
  8. ^ a b c d Survey of energy resources (PDF) (edition 21 ed.). World Energy Council. 2007. pp. 93–115. ISBN 0946121265. Retrieved 2007-11-13.
  9. ^ a b c Dyni, John R. (2006). "Geology and resources of some world oil shale deposits. Scientific Investigations Report 2005–5294" (PDF). United States Department of the Interior, United States Geological Survey. Retrieved 2007-07-09. {{cite journal}}: Cite journal requires |journal= (help)
  10. ^ "Annual Energy Outlook 2006" (PDF). Energy Information Administration. February 2006. Retrieved 2008-04-18. {{cite journal}}: Cite journal requires |journal= (help)
  11. ^ Andrews, Anthony (2006-04-13). "Oil Shale: History, Incentives, and Policy" (PDF). Congressional Research Service. Retrieved 2007-06-25. {{cite journal}}: Cite journal requires |journal= (help)
  12. ^ "NPR's National Strategic Unconventional Resource Model" (PDF). United States Department of Energy. April 2006. Retrieved 2007-07-09. {{cite journal}}: Cite journal requires |journal= (help)
  13. ^ "A study on the EU oil shale industry viewed in the light of the Estonian experience. A report by EASAC to the Committee on Industry, Research and Energy of the European Parliament" (PDF). European Academies Science Advisory Council. May 2007. Retrieved 2007-11-25. {{cite journal}}: Cite journal requires |journal= (help)
  14. ^ a b Brendow, K. (2003). "Global oil shale issues and perspectives. Synthesis of the Symposium on Oil Shale. 18–19 November, Tallinn" (PDF). Oil Shale. A Scientific-Technical Journal. 20 (1). Estonian Academy Publishers: 81–92. ISSN 0208-189X. Retrieved 2007-07-21.
  15. ^ Qian, Jialin; Wang, Jianqiu; Li, Shuyuan (2003). "Oil Shale Development in China" (PDF). Oil Shale. A Scientific-Technical Journal. 20 (3). Estonian Academy Publishers: 356–359. ISSN 0208-189X. Retrieved 2007-06-16.
  16. ^ "About Oil Shale". Argonne National Laboratory. Retrieved 2007-10-20.
  17. ^ Altun, N. E.; Hiçyilmaz, C.; Hwang, J.-Y.; Suat Bağci, A.; Kök, M. V. (2006). "Oil Shales in the world and Turkey; reserves, current situation and future prospects: a review" (PDF). Oil Shale. A Scientific-Technical Journal. 23 (3). Estonian Academy Publishers: 211–227. ISSN 0208-189X. Retrieved 2007-06-16.
  18. ^ Rapier, Robert (2006-06-12). "Oil Shale Development Imminent". R-Squared Energy Blog. Retrieved 2007-06-22. {{cite journal}}: Cite journal requires |journal= (help)
  19. ^ a b Bartis, James T.; LaTourrette, Tom; Dixon, Lloyd; Peterson, D.J.; Cecchine, Gary (2005). "Oil Shale Development in the United States. Prospects and Policy Issues. Prepared for the National Energy Technology Laboratory of the U.S. Department of Energy" (PDF). The RAND Corporation. ISBN 978-0-8330-3848-7. Retrieved 2007-06-29. {{cite journal}}: Cite journal requires |journal= (help)
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