Unconventional Oil Reserves in and Around the US
Given total world conventional oil reserves of around 1.3 trillion barrels, the recoverable estimates for tar sand oil would increase world reserves by over 25 percent.
Is it practical to produce oil from tar sands? Yes—Canada has been doing so for years. In 2006, it produced over 1.1 million barrels per day, and could produce 3 million barrels a day by 2020.
How are the tar sands mined? Either by underground or open-pit mining, with open-pit mining currently more common. Sand is scooped out of a huge hole in the ground by giant shovels and carried away by dump trucks for processing.
What happens after tar sands are mined? The sands are trucked to an extraction plant, where hot water is used to separate the bitumen from the sand. Then the bitumen needs to be further refined into usable distillates, such as diesel, gasoline, number 2 home heating oil, etc. Of course, all crude oil has to be refined to be usable—there’s a reason it’s called “crude oil” and not “ready-to-use oil”—but bitumen, being thicker and more sludgy, needs additional refinement compared to conventional crude.
What are the costs of extracting oil from tar sands? Compared to conventional crude, producing oil from tar sands is dollar, energy, and water intensive. To begin with, mining the sand requires giant machinery. Trucking it to the extraction plant requires huge trucks (some can carry up 320 tons—that’s equal to two 1,600 sq. ft homes!).
Massive quantities of water are used in separating the bitumen from the sand—several barrels of water are required for each barrel of oil. The water has to be heated for the extraction process, and the additional refinement that bitumen requires needs more energy still. Overall, it takes the equivalent of 1 barrel of oil to create 5 – 6 barrels from tar sands. This is roughly double the energy used to produce a barrel of crude by conventional means.
As a result of the additional steps in the process, the extra fuel, water, and machinery required, it costs around $25 to produce a barrel of oil from tar sand, as opposed to around $5 from conventional drilling or $15 from deep water drilling.)
What Pollution or Waste Is Given Off? There is solid waste—for example, sand sans bitumen—which is the least troublesome waste. It can be trucked back to the mine and used to fill it in when done.
More serious are the greenhouse gases (primarily carbon dioxide) given off, since they are implicated in global warming. Producing oil from tar sands releases around 1.5 times as much greenhouse gas as producing it from conventional crude oil.
Also, remember all that water used in the process? Well, large amounts of water contaminated with naphthenic acid are produced—entire lakes worth. Right now, there is no means to permanently clean up this liquid waste.