I saw this last time and i decided to skip it, but i see it again and wanted to chime in.
1st: There is a way to compare infinite sets its called cardinality. Not sure it exactly applies here as you still have infinite numbers just each unit is 10 to 3 in size. But I think you were referring the cash generated per barrel.
2nd: There is not an infinite supply of oil in the world. It is a relatively finite resource. (It is technically renewable, but not in a convenient time frame. I.e. millions of years.) I think the estimates are Saudi Arabia has ~60 years of proven reserves if it continues to pump at current rates.
I'm making an argumentative point, not a mathematical proof.