Tar Sands Oil

Tar sands is a petroleum product that is collected off sands in Alberta and other places up North.

The fields are described here:

https://en.wikipedia.org/wiki/Western_Canadian_Sedimentary_Basin#Oil_sands

https://en.wikipedia.org/wiki/Cold_Lake_oil_sands

It resembles the bitumen that is used to make asphalt, a very low-quality petroleum product. Extraction is complicated process that uses at least five times as much energy as conventional oil. It is made to flow in early part of production with steam or a solvent. It tends to solidify in equipment, or at least becomes so thick that it does not flow. To transport it in tank cars, a solvent such as pentane is added. The mixture is then very flammable. A train derailed and six cars burned up in one incident. The disaster left 42 people dead.

https://en.wikipedia.org/wiki/Lac-M%C3%A9gantic_rail_disaster

The desired transport of these low-quality oils is a pipe line, simply because it does not make much money. Some years the price is almost the cost of getting it and transporting it to the refinery. It does make a very low-grade diesel fuel eventually, only used in very large diesel engines. The companies want to transport it by pipe because this is the cheapest way.

The business of heavy crude and its costs is explained here. The Nebraska pipe line was not approved across the Ogallala aquifer. It is to go through the Eastern part of Nebraska.

https://oilprice.com/Energy/Crude-Oil/Keystone-XL-Is-Far-From-Certain.html

Why make such bad oil product? Well, it just fills in the bottom end of oil supply, and more oil is available for making diesel to run trucks (from normal sources of crude oil). And technically, the tar sands oil can be refined. You can "pull" hydrogen from other sources of fossil fuel (natural gas etc.) and add that to tar sands oil. That is not cheap, and you are wasting hydrogen from the natural gas. The website Narwhal explains:

Also from their website: "In the US, 59 of the 134 refineries are equipped with coker units. Approximately 30% of the US's bitumen refining capacity is in the nine Gulf of Mexico refineries TransCanada seeks to supply through its controversial Keystone XL pipeline. "

The pipes are some 18-42 inches in diameter and made by welding the pieces together. There is also a seam along the length when the pipe itself was manufactured. The pipe is unlike the 6 inch pipe used to transport conventional oil that flows much more easily. The most famous disaster is a rip in the 30 inch pipe that went near Kalamazoo, Michigan.

Political deals made the pipe exempt from a tax that is normally collected to take care of possible spills. If the product is diluted with an organic solvent, that quickly evaporates and the heavy bitumen sinks, usually polluting the water table underneath. Details of the spill are found here.

http://priceofoil.org/content/uploads/2012/05/Irrational-exemption_FINAL_14May12.pdf

Why is an 18 inch or 36 inch pipe more likely to break? The pipes are relatively thin metal compared to their diameter:

Pumping stations pose some risk, but as they are manned, a leak there would be quickly shut down. A Youtube video describes a pump station. Link below

https://www.youtube.com/watch?v=4HQIK_OUDzY

We are getting into chemical engineering here, and I do not have access to the journals, but bits of science are found on the Internet free. The summary is that there are two spills so far, Arkansas and Kalamazoo, about 4 times the incidence of conventional oil spill, per mile of piping. The tar sands bitumen contains dilute sulfuric acid (corrosive). This and the higher temperature and pressure in the pipes contributes to corrosion.  Some studies dispute the corrosion at anywhere below 100C (boiling point of water), but companies have nevertheless added epoxy coatings to prevent corrosion.

Whatever the cause of spills, they continue in these pipes. Fourteen more minor incidents are catlogues in this document.

http://blog.nwf.org/wp-content/blogs.dir/11/files/2011/06/320115006H_CAO_06032011.pdf

My guess on the study of future ruptures is that the higher pressure used will be the main culprit. The risks and each pipeline plan needs community input. Do you need the jobs that badly that you want the pipeline? States, the US government and Canadian companies should not overrule the local interests. After a spill, your land is worthless.