A barrel of light Texas crude weighs 384 lbs (source). 4 billion barrels weighs 768 million tons. How are they going to turn 600 million tons of some stuff into 768 million tons of some other stuff? Where does the extra 168 million tons come from? And furthermore, the stuff they start with is mostly water, and the other stuff they end up with has essentially no water. Where does the water go, and how do they make up the deficit?
I think that you don't know the size of a barrel of oil. Try using forty two gallons/barrel. It works out better.
But...but...but you're confusing the pipedream (or bong-dream) with facts!
As another astute observer (who must have learned arithmetic in school, so it couldn't have been a public school) pointed out in a letter to the WSJ, to replace just the ANWAR oil with turkey poo-oil, we'd need about 35 turkeys for every living American, we'd be importing more grain than we do oil now, and the resulting product would cost more per gallon than Dom Perignon.
Otherwise, there's no reason a technologically savvy nation like the USA couldn't do it!
(We 'mericans were the first and only to put a man on the moon! Why couldn't we run our cars on $250/gal turkey-poo oil?)
They're not making crude oil. They are making the equivalent of #2 fuel oil. Considerably lighter.