The Japan export is basically a false legend. Look at a map.
It is 3,577 miles from Valdez, Alaska to Tokyo, Japan.
It is 1,274 miles from Valdez, Alaska to Anacortes, Washington. (largest Washington refineries)
It is 2,253 miles from Valdez, Alaska to El Segundo, California (major refinery near Los Angeles)
Until 1996 it was illegal to export Alaskan North Slope Crude oil because of the Congressional Approval used to create the pipeline.
In the mid-late 1990’s, because of a glut of oil on the West coast, this was relieved and less than 5% of ANS crude was exported. That quit by 2000.
I am not talking about the physical product but figures on paper, or a screen. It does not vary even if you are talklng about crude of different gravity. Like gold that stays in the vault, it still changes hands.