September 11, 2012
Oil sands are found in about 70 countries in the world, from Venezuela and Trinidad/Tobago in the Caribbean to as far north as Russia. By far, the main deposits are hosted within Cretaceous rocks of Venezuela and Canada, and among these, the largest is the Athabasca oil sands of northeast Alberta.
Oil sands consist of bitumen (soluble organic matter, solid at room temperature) and host sediment, with associated minerals, and excluding any related natural gas. The crude bitumen within the sands is a naturally occurring viscous mixture of hydrocarbons (generally heavier than pentane), often with sulphur compounds, that will not flow to a wellbore in its natural state. Upon heating, the bitumen will flow, and on a hot summers’ day, bitumen oozes from the outcrops along the river valleys in northeast Alberta.
Since the 1990s, bitumen has evolved as a major source of energy in Canada, largely a result of three major factors:
In Canada, the oil sands occur in Cretaceous fluvial-estuarine deposits of northeastern Alberta, covering an area >140,000 km2. Bitumen is also found in Devonian carbonates (most notably within the Grosmont Formation) but this bitumen has not been commercially produced.
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