A couple months back, I did a tank job for a tank farm in New Haven, CT, a port and distribution point for much of New England.
Trucks loaded fuel out of there day & night. There were independents, Mobil, Shell, Hess and a bunch of others picking up gasoline at the rack. They all sell product from the same tank. Some add a 5-gallon bucket of some special crap so they can say their product is different, but it's all from the same source.
It's the same deal with heating oil and diesel.
Same deal with the crap running through the pipelines. It's a commodity. Company x puts in so many barrels and expects to get the same out at the end of the line. They don't care if it came from their operations or anyone elses, just as long as the quantity is correct.
There is no way a consumer can say with any reasonable level of certainty that the fuel came from Texas of Saudi or Alaska.
Well, Citgo is Venezuelan oil and ironically, the refinery at Lake Charles that will get the bulk of the SPR oil also belongs to Venezula.