It's not just a matter of building more refineries to process it. The different API Gravities of the oil are used to output different products. Gasoline, jet fuel, etc.
So yes, you could modify refineries (at significant expense) to process different grades of crude, but in order to target different outputs we still need to import the different grades of oil because the refineries end up mixing/matching to get the levels they need. The US produces a lot of light oil, but less of the medium/heavy grades you'll find in Canada or the Middle East.
So yes, you could modify refineries (at significant expense) to process different grades of crude, but in order to target different outputs we still need to import the different grades of oil because the refineries end up mixing/matching to get the levels they need. The US produces a lot of light oil, but less of the medium/heavy grades you'll find in Canada or the Middle East.