EGEE 101
Energy and the Environment

Oil Sands and Oil Shale

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We have three fossil fuel resources that can replace crude oil. They are oil sands (also formally known as tar sands), oil shale, and coal liquefaction or gasification. These are also known as non-conventional sources.

Oil Sands

Oil sands are important because they are abundant, and Canada has large reserves that they are upgrading to form a "synthetic" crude oil. The major importer of this fuel is the US. By now, you should realize that the stages in the formation of crude oil are as follows:

Organic   → Kerogen  → Bitumen  → Crude Oil & Natural Gas

So we will see that this is similar to the formation of oil shale. The bitumen is a viscous semisolid. It is so viscous (and often solid in cold weather) that traditional oil extraction techniques will not work. Thus, the overburden is removed, and the tar sand extracted in a similar manner to the extraction of coal from a surface mine (although I don't think they need to use explosives to break up the sand in the summer).

The origin of the oil is a controversial subject among geologists, but the predominant theory is that it evolved in highly organic Cretaceous shales in the southern portion of the Alberta Sedimentary Basin. Underground pressure forced the oil to soak into the existing silt grade sediments and localized sand bodies of the McMurray formation.

Syncrude, Canada

The bitumen forms a solid in cold weather, so the tar sands are a rock, but in summer the consistency is that of thick mud. The tar sands are either trucked to the processing plant or sent to a slurry plant, then to the processing plant via a pipeline (why?). Chemicals and heat (retorting) are used to separate the sand grains from the bitumen. The sand then goes back to reclaim the land (fills in the massive holes!), and the bitumen is refined using similar technology to that already discussed for crude oil.

The oil we're talking about extracting here is considered "heavy" oil, a term popular with the masses, but not necessarily accurate, since it refers to the oil's high density. This is in contrast to "light" oil, which is higher quality oil, and which is of lower density, yielding gasoline products more efficiently. The process of upgrading all the "heavy" oil (low H/C ratio) from the oil sands requires lots of hydrogen (usually obtained from methane and from the cooking process). The synthetic crude oil produced is sent via pipeline to refineries in Canada and the US. You might be using gasoline or products from oil sands as our closest refinery in Warren, PA uses this synthetic crude oil along with PA crude oil. The synthetic crude is rich in asphalt and so when you drive new roadways or have a new roof (asphalt shingles) you again might be using oil sand material.

This link helps explain the extraction process a bit more (surface mining and some in situ extraction: drilling, steam, pumping). Goals here are to understand how surface mining and extraction of the bitumen occurs. 

Three trucks hauling their soil sand cargos to be processed.
Trucks hauling their oil sand cargos to be processed.
Credit: Syncrude

Canadian oil sands deposit is the world's largest. To give you some idea of how large their reserve is:

  • It can supply Canada's energy needs for 475 years.
  • It can supply the world's energy needs for 15 years.
  • The reserve is 5 times the Saudi Arabia crude oil reserve.

The Canadian companies extracting the bitumen can make a profit with current oil process this is economically feasible and profitable. It is also a reasonably secure energy source given that now the US and Canada are trading partners, and are friendly. Text Version (click to reveal)

Dr. Mathews: Question, where is the capital of Canada? Well, it is not Toronto, it's not Montreal, and it certainly isn't Quebec. Of course, it is Ottawa. But it is a very strange choice to have the capital sort of far away from everything. And there is a good reason for that. Relationships between the United States and Canada have not always been friendly. Remember that you are a rebellious nation, you gave up the good guidance of the king and the queen, in favor of this democracy crap. And of course when you did the Canadians remained loyal. And so there was definitely a fear of an American invasion into Canada. And I forget what the statistic is, so please do not quote me on this, but it is something like, eighty percent of the Canadian populous lives within one-hundred miles of the Canadian border. You certainly couldn't pick Toronto because of the fear that it would be very easily captured. And you certainly do not want to have your capital city captured. And so the queen, in all of her wise ways, decided that she was going to place the capital of Canada in Ottawa just to be further away. And of course you wouldn't want to put it in Quebec because of the French influence. And that is where it stands. And you can go and see that is has a very similar parliament to the British system and by law, the two benches need to be at least two sword distances apart, also that is an interesting thing. But you haven't always been friendly with the Canadians.

Oil Shale

We also can find carbonaceous rocks that contain significant organic material in the form of Kerogen (with perhaps some bitumen). The prevailing thought regarding the formation of this material is algal blooms in lakes. There is a summer (thick) layer and a thinner winter layer that dies and settles on the bottom of the lake. This created an organic-rich sediment that eventually formed a source rock. The many layers of source rock that are formed indicated that this process might have been occurring for a few million years. Thus, there is a lot of organic material in oil shales. Unfortunately, the long time periods required for crude oil formation and high temperatures have not been obtained and so we have a source rock with very immature crude oil precursor. We can mine the oil shale, crush, and retort (heat with steam) to extract the kerogen. This can then be upgraded or gasified to supply electricity. We have large quantities of oil shale in the US (large areas of the oil shale containing land, are owned by the US Navy (why?). Worldwide the 5 to 6 times the world resource of petroleum. But have you ever heard of it? Currently, it is still cheaper to purchase crude oil than to produce oil from the treatment of oil shale kerogen. The locations in the US are out West mostly within the Green River formation of Utah/Wyoming.

Gasification of Coal

Recall that when South Africa was embargoed because of the Apartheid policy, they had to find an alternative to crude oil. They used coal to supply all of their chemical needs from gasoline, to fertilizer, and explosives. Similar approaches have been used in World War II in Germany (the birthplace of gasification technology), Britain, and Japan. So with gasification of coal, we can produce transport fuels, chemicals, and electricity.