The thing is that refineries are designed around refining specific types/qualities of crude. The US produces a lot of light (low viscosity) and sweet (low sulfur) crude oil, but a lot of our refineries are actually set up to refine heavy (high viscosity) and sour (high sulfur) crude, because it's cheaper to buy and more advanced refineries can make a larger profit on it. And as you might have guessed, most of the crude produced is Canada is heavy sour crude. A lot of the majors/super majors will pump light and sweet US crude and then export a good portion of it overseas to countries that don't have the same refining capabilities and then buy the cheap and dirty stuff that they know how to handle. I'm not a down stream expert, but I would imagine going from heavy sour crude to light sweet crude is probably going to be costly, even if it's easier than going in the other direction. What I expect is more likely is that refineries won't stop buying Canadian crude and will just raise prices, instead.
The thing is that refineries are designed around refining specific types/qualities of crude. The US produces a lot of light (low viscosity) and sweet (low sulfur) crude oil, but a lot of our refineries are actually set up to refine heavy (high viscosity) and sour (high sulfur) crude, because it's cheaper to buy and more advanced refineries can make a larger profit on it. And as you might have guessed, most of the crude produced is Canada is heavy sour crude. A lot of the majors/super majors will pump light and sweet US crude and then export a good portion of it overseas to countries that don't have the same refining capabilities and then buy the cheap and dirty stuff that they know how to handle. I'm not a down stream expert, but I would imagine going from heavy sour crude to light sweet crude is probably going to be costly, even if it's easier than going in the other direction. What I expect is more likely is that refineries won't stop buying Canadian crude and will just raise prices, instead.