“why are we still importing Arab oil???”
Refineries are configured for a particular kind if oil, so oil that is being refined into a particular product is sent to a refinery that is set up to handle that kind of oil, into that kind of product.
The big US refineries in the Gulf mostly handle heavy crude like you get from Venezuela and Mexico, so that is mostly what we import. You can produce asphalt with it. Arab oil tends to be very light sweet crude, so it can be better used for certain kinds of lighter petroleum products.
There is some degree of interchangability, and all the folks in the business are free to try and get the best price deal wherever they can.