Oil sands
sands naturally soaked with petroleum / From Wikipedia, the free encyclopedia
Oil sands, or tar sands are an unconventional source of petroleum. The oil sands are a mixture of sand, clay and water in a dense and extremely sticky form of petroleum called bitumen.
Natural bitumen is found in many countries, with the largest quantities in Canada, Kazakhstan and Russia.[1]
The worldwide deposits may be over two trillion barrels (320 billion cubic metres).[2] These estimates include deposits that have not yet been discovered. Around 70% of all known reserves are in Canada.
Oil produced from bitumen sands is often said to be unconventional oil. The production process takes energy, so the net energy gain is smaller than traditional oil. Making liquid fuels from oil sands makes 12 percent more greenhouse gases per barrel of oil than traditional oil.[3] Oil sands have only recently been needed. Higher prices allow this more expensive type of oil production to sell.