Oil sands: a different kind of reservoir
Oil sands are deposits of sand, clay and water saturated with bitumen, a very heavy and viscous form of petroleum that will not flow at reservoir temperature. The largest deposits lie in the Athabasca, Cold Lake and Peace River regions of northern Alberta, Canada, and similar extra-heavy crude is found in Venezuela's Orinoco Belt.
Because bitumen is so thick, it is either upgraded into synthetic crude oil or blended with a lighter diluent (producing "dilbit") before it can move through pipelines to refineries.
Surface mining
Where deposits are close to the surface, overburden is removed and the oil sand is dug up with shovels and haul trucks. Hot water separates the bitumen from the sand, and the remaining tailings are managed in ponds and reclaimed over time.
In-situ recovery
Most oil sands reserves are too deep to mine. Steam-assisted gravity drainage (SAGD) uses paired horizontal wells: steam from the upper well heats the bitumen, which drains to the lower well and is pumped to surface. Cyclic steam stimulation (CSS) uses a single well.
What operators measure
Steam-to-oil ratio, well-pair temperatures and pressures, water recycling rates, tailings volumes, land reclamation progress and greenhouse gas intensity are tracked continuously, and much of this data starts on a tablet or a handheld in the field.
3 depositsAthabasca, Cold Lake and Peace River, across about 142,000 km² of northern Alberta
Since 1967when the first commercial oil sands plant opened near Fort McMurray
About 80%of the recoverable resource is too deep to mine and is produced in situ, mostly by SAGD
Largest sourceof Canada's crude oil production, shipped by pipeline to the U.S. and the Pacific coast