Tar sands
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Oil_sands_open_pit_mining.jpg
Tar sands, also referred to as oil sand or bituminous sand, is a combination of clay, sand, water, and bitumen. Tar sands are mined for the oil rich bitumen which is refined into oil. Conventional oil is extracted by drilling traditional wells into the ground whereas tar sand deposits are mined using strip mining techniques. On Average Bitumen contains
83.2% Carbon 10.4% Hydrogen 0.94% Oxygen 0.36% Nitrogen 4.8% Sulphur
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Location
Tar sands deposits are found all over the world, with the largest deposits located in Venezuela and Alberta, Canada. While not a proven reserve of oil, tar sands represent as much as 66% of the world's deposits of oil, with 34% (286 km³ or 1.8 trillion barrels) in the Venezuelan Orinoco tar sands deposit, 32% (270 km³ or 1.7 trillion barrels) in Canada's Athabasca Tar Sands deposit and the remaining 33% (278 km³ or 1.75 trillion barrels) in conventional oil, much of it in Saudi Arabia and other Middle-Eastern countries.
Extraction process
Extraction_separation_cell.jpg
Hot water is added to the sand, and the resulting slurry is piped to the extraction plant where it is agitated and the oil skimmed from the top. [1] (http://www.oilsandsdiscovery.com/oil_sands_story/extract.html) Provided that the water chemistry is appropriate to allow bitumen to separate from sand and clay, the combination of hot water and agitation releases bitumen from the oil sand, and allows small air bubbles to attach to the bitumen droplets. The bitumen froth floats to the top of separation vessels, and is further treated to remove residual water and fine solids. Bitumen is much thicker than traditional crude oil, so it must be either mixed with lighter petroleum (either liquid or gas) or chemically split before it can be transported by pipeline for upgrading into synthetic crude oil.
It is estimated that around 80% of the Alberta tar sands are too far below the surface for the current open-pit mining technique. In situ mining techniques are being established to extract the oil, which requires a massive injection of steam into a deposit, thus liberating the bitumen underground, and channelling it to extraction points where it would be liquified before reaching the surface.[2] (http://www.oilsandsdiscovery.com/oil_sands_story/insitu.html) This type of extraction requires a traditional oil well working in tandem with a steam injection machine. Major disadvantages of this process include the need for a huge local water source, the energy required to boil the water, a large waste water disposal problem, as well as potential environmental damage below the surface. Critics argue that heavy water use makes scaled up production infeasible; proponents argue that water efficiency will improve as the technology is further refined.
The Canadian Athabasca oil sands deposit has an estimated reserve production capacity of 750,000 barrels (150,000 m³) of crude oil per day using the current hot water processes. As traditional or conventional sources of oil suffer from depletion, non conventional sources of oil such as oil sands will increasingly be relied upon to make up the difference in future global oil production. Canada uses the most oil in one day in the world (1.6 billion barrels a day) per capita. This synthetic crude oil takes two tons to fill one barrel of upgraded synthetic crude oil.
See also
External links
- History of Canada's Oil Sands (http://www.oilsandsdiscovery.com)
- Canadian Oil Sands (http://www.cos-trust.com) - Investment Trust in Alberta Oil Sands
- Syncrude Canada (http://www.syncrude.com) - Largest producer of crude oil from oil sands (meets 13% of Canadian oil needs)
- Suncor (http://www.suncor.com) - Canadian Energy Company that started developing Crude Oil in Alberta in 1967
- Oil Sands Production Statistics for last 6 Years (http://www.capp.ca/raw.asp?x=1&dt=NTV&e=PDF&dn=34093) (pdf)da:Tjæresand