Alberta's internationally recognised "tar sand" reserves are now put at the equivalent of more than 175 billion barrels of crude oil. To extract bitumen from the surface deposits of tar sand, which make up about 20% of reserves, huge excavators scrape away the topsoil and the underlying tar sands are lifted into huge dump trucks. The surficial tar sands are trucked to extraction processes, where they are steamed to extract the heavy, bitumenous oil. The resulting oil is piped to refineries. This first step of tar sand extraction is estimated to result in gasoline that carries a burden of "at least five times more carbon dioxide" then would conventional "sweet crude" oil production. According to the Canada National Energy Board engineering break throughs are anticipated to reduce this carbon dioxide emission burden.
Because the remaining 80 percent of the sands are too deep to be mined, steam is injected into these deeper oil sands, loosening the bitumen and allowing producers to draw it upward, as indicated in the graphic. The process was known as "steam-assisted gravity drainage." It is said to be more efficient than the "truck and steam" process.
Although producers recycle much of their water, about one barrel of water is lost for every barrel of oil culled, according to the Pembina Institute, a Canadian environmental group.
Developers are required to restore oil sand mining sites to at least the equivalent of their previous biological productivity, which involves revegetation and drainage restoration. None of this has yet been done on a large scale, however.
We have to say that large scale tar sand extraction has all the earmarks of being Un-TreeHugger. As they are supporting brand new, expensive technologies, investor attitudes toward Kyoto committments are naturally cynical if not outright hostile. How could they compete with carbon trades as a hedge with a 5X carbon dioxide handicap? It would take a great deal of wind turbine investment to offset those extra emissions. Which helps us to understand this.
If Canada has North America's lungs, auto owners in US are it's mouth, gobbling supersize meal after oil meal to keep the wheels rolling, which keeps the trucks driving and steam flowing underground. Reducing our gasoline consumption sounds like the best thing we can do to protect the Arboreal Forests of the northcountry.