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'Oil shale' is fine-grained sedimentary rock containing significant amounts of kerogen (a solid mixture of organic chemical compounds), from which liquid hydrocarbons can be manufactured. The name ''oil shale'' is somewhat misleading as it need not be shale, and the hydrocarbon in it is not oil. In addition to the oil shale, there are other groups of organic-rich sedimentary rock—bitumen-impregnated rocks (tar sands and petroleum reservoir rocks), humic coals and carbonaceous shale.WEC, p. 74

The kerogen in oil shale can be converted to synthetic crude oil through the chemical process of pyrolysis. When heated to a sufficiently high temperature a vapor is driven off which can be distilled (retorted) to yield a petroleum-like shale oil—a form of non-conventional oil—and combustible shale gas (''shale gas'' can also refer to gas occurring naturally in shales). Oil shale can also be burnt directly as a low-grade fuel for power generation and heating, and be used as a raw material in the chemical and construction materials industries. Currently oil shales are used commercially for oil production in Estonia, Brazil and China, for power generation in Estonia, China, Israel and Germany, for cement production in Estonia, Germany and China, and for chemical industry in Estonia and Russia.
WEC, p. 73



World deposits of oil shale are estimated to equal 2.9–3.3 trillion barrels of recoverable oil, 1.5–2.6 trillion barrels of which are in the United States.WEC, p. 81-82




Attempts to develop these reserves, over a period of over 150 years, have had temporary success.^[1]
Although still seen as a potential future alternative to conventional oil, world production reached a peak of 46 million tons in 1980 before falling to about 16 million tons in 2000 due to the lower cost of conventional petroleum.^[2]
As the oil shale industry has a number of environmental impacts, environmentalists have expressed concern over the extraction of shale oil, and protests appear to have contributed to the halting of the developing industry in Australia.^2[3]

Contents

Geology

Reserves

Industry

History

Applications

Extraction

Products

Economics

Environmental considerations

See also

Footnotes

References

External links

Geology

Main articles: Oil shale geology

Outcrop of Ordovician kukersite oil shale, northern Estonia.

Fossils in Ordovician kukersite oil shale, northern Estonia.

Oil shales vary considerably in mineralogical and chemical composition. Different types of oil shales show a range of mineral content, type of kerogen, age, and depositional history, including the organisms from which they were derived.

Depending on their composition, oil shales have been divided into three categories: carbonate-rich shale, siliceous shale and cannel shale.

Oil shales could be classified also according to their kerogen type, which is a function of the hydrogen, carbon and oxygen content of the organic matter.
Based upon environment of deposition, oil shales are terrestrial, lacustrine, or marine.

Reserves

Main articles: Oil shale reserves

The world deposits of oil shale are estimated to be equal to 2.9-3.3 trillion barrels of potentially recoverable oil. Although oil shale resources occur in many countries, only 33 countries possess deposits of possible economic value.
Total resources of these countries are estimated at 411 gigatons, which is enough to yield 2.9 trillion U.S. barrels.
Among those, the USA accounts for 62 % of the world resources, and the USA, Russia and Brazil together account for 86 % in terms of shale oil content.
The above mentioned figure of total reserves is tentative because several deposits have not been explored sufficiently to make accurate estimates, and other deposits were not included.
WEC, p. 77

Industry

Currently oil shale is used industrially in Brazil, China, Estonia and to some extent in Germany, Israel and Russia, while several other countries research their reserves, have experimental production or have phased-out their oil shale industry.
WEC, p. 75-77

Estonia accounts for about 70 % of the current world's oil shale production.

The oil shale is mined either by traditional underground mining or surface mining. There are several mining methods, but all of them fragment the oil shale and transport it to a power plant or retort. Main methods of surface mining are open pit mining and strip mining. The main sub-surface mining method is the room-and-pillar method.

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History

Main articles: History of the oil shale industry

Oil shale has been used since ancient times. Modern industrial oil shale mining began in 1837 in Autun, France, followed by Scotland, Germany and several other countries.

The first oil shale retort was constructed in the United States in 1855.

The second wave of oil shale industry started just before World War I, but was phased-out in most of countries after World War II because of high processing costs and cheap conventional petroleum.


Due the 1973 oil crisis, oil shale industry was restarted in several countries, but was for the most part shut down in mid of 1980s. The global oil shale industry started to increase again slightly only in mid-1990s. In 2003, an oil shale development program was restarted in the United States, and the commercial leasing program for oil shale and tar sands was introduced in 2005.
Nominations for Oil Shale Research Leases Demonstrate Significant Interest in Advancing Energy Technology. Press release

What's in the Oil Shale and Tar Sands Leasing Programmatic EIS

Applications

Oil shale can be used as a fuel for thermal power plants, where the shale is burned like coal to drive steam turbines. Currently there are oil shale-fired power plants in Estonia (2967 MW installed capacities), Israel (12.5 MW), Germany (9.9 MW), and China.


While some countries have closed their oil shale-fired power plants (e.g. Romania) or converted to other fuels (e.g. Russia), some other countries are looking for construction of these power plants (e.g. Jordan and Egypt), or burn oil shale at the power plants together with coal (e.g. Canada and Turkey).

WEC, p 85-90

Extraction

Main articles: Oil shale extraction

Oil shale extraction is a process of converting kerogen to synthetic crude and shale gas through the chemical process of pyrolysis. Most extraction technologies involve heating shale to the temperature at which kerogen is decomposed or pyrolysed in the absence of oxygen into gas, condensable oil, and a solid residue. Other technologies are based on the solvent processes of reactive fluids.

Oil shale extraction may involve either ''ex-situ'' (above-ground) or ''in-situ'' (subsurface) processing.

Products

Shale oil also is or could be used for production of products such as specialty carbon fibers, adsorbent carbons, carbon black, cement, bricks, construction and decorative blocks, soil additives, fertilizers, rock wool insulating material, glass, and pharmaceutical products.
However, oil shale use for production of these products is still small or only in experimental stages.
Some oil shales yield byproduct sulfur, ammonia, alumina, soda ash, uranium, and nahcolite production as shale oil extraction byproducts. In 1946-1952, a marine type of Dictyonema shale was used for uranium production in Sillamäe, Estonia, and in 1950-1989 alum shale was used in Sweden for the same purpose.
Oil shale gas could be used as a substitute for natural gas; however at the current price level this is not economic.

Economics

Main articles: Oil shale economics

Medium-term prices for light-sweet petroleum, 2005-2007 (not adjusted for inflation).

According to a survey conducted by the RAND Corporation, a surface retorting complex (mine, retorting plant, upgrading plant, supporting utilities, and spent shale reclamation) is unlikely to be profitable unless crude oil prices are at least US$70 to US$95 per barrel.
Once commercial plants are in operation and experience-based learning takes place, costs are expected to decline to US$35–US$48 per barrel after 12 years. After production of 1000 million barrels, costs are estimated to decline further to US$30 – US$40 per barrel.

Royal Dutch Shell has announced that its in situ extraction technology could be competitive at prices over US$30 per barrel, while some other technologies at full scale production claim to be feasible at the oil price even less than US$20 per barrel.
Shell's ingenious approach to oil shale is pretty slick Linda Seebach


Analysis: Israel sees shale replacing oil Leah Krauss


To increase efficiency of oil shale retorting, several co-pyrolysis processes have been proposed or tested.
A critical measure of the viability of oil shale is the ratio of energy produced by the shale divided by the energy used in mining and processing (Energy Returned on Energy Invested - EROEI). A 1984 study estimated the EROEI of the different oil shale deposits to vary between 0.7-13.3.

Royal Dutch Shell has reported an EROEI about three to four on its in-situ development, Mahogany Research Project.

Tapping the Rock Field Spencer Reiss

Water is also needed in the oil shale retorting process, which may pose a problem in areas without surplus water supply.

Environmental considerations

Main articles: Environmental effects of oil shale industry

The oil shale industry can leave environmental footprints on the land, atmospherically and in the groundwater, if the risks are not managed correctly. Opposition to one oil shale program has resulted in it being put on hold in Australia.^[3]
Surface-mining of oil shale deposits has all the environmental impacts of open-pit mining. In addition, the combustion and thermal processing generate waste material, which must be disposed of, and atmospheric emissions, including carbon dioxide, a major greenhouse gas. Experimental in-situ conversion processes and carbon capture and storage technologies may reduce some of these concerns in future, but may raise others, such as groundwater pollution.^[5]

See also

★ Oil reserves

★ Non-conventional oil

★ Abiogenic petroleum origin

★ World energy resources and consumption

★ Future energy development

★ Mitigation of peak oil

★ Core research center

★ Mahogany research project

★ Synthetic Liquid Fuels Program

★ Green River Basin

★ Tar sands

★ Bituminous coal

Footnotes

1.

2.

3.
Climate-changing shale oil industry stopped Greenpeace Australia Pacific

4.
Climate-changing shale oil industry stopped Greenpeace Australia Pacific

5.

References

★ Survey of energy resources, , , , World Energy Council (WEC), ,

External links

★ Oil Shale. A Scientific-Technical Journal. Estonian Academy Publishers. ISSN 0208-189X

★ Selected online oil shale publications by the U.S. Geological Survey

★ Oil Shale: Toward a Strategic Unconventional Fuels Supply Policy, by Daniel Fine, Ph.D.Heritage Foundation 2007-03-08

★ Oil from Shale could meet need, UPI Dr. Daniel Fine Ph.D.

★ WorldOil.com - Oil shale back in the picture

★ Statement Of Thomas Lonnie Assistant Director for Minerals, Realty & Resource Protection, Bureau of Land Management, U.S. Department of the Interior before the Senate Energy and Natural Resources Committee Oversight Hearing on Oil Shale Development Efforts, Bureau of Land Management, 2005-04-12

★ "The Scandinavian Alum Shales" by Astrid Andersson, Bertil Dahlman, David G. Gee and Sven Snall, 1985 ISBN 91-7158-334-3

★ 27th Oil Shale Symposium

★ Estonian oil shale

★ Ullmann's Encyclopedia of Industrial Chemistry article on oil shale Retrieved on 2007-08-04