Like I said, those are guaranteed cuantities of oil. The stuff that is unreachable isn't recorded in the data.
Still, that makes my point even more relevant. Of that oil, not all of it will be used, thus limiting the time-line.
My point was just to show how over-the-top we are in our consumption. How long have we using crude en masse? 60 years?
That's not a very long time, considering how many million years it takes the make the stuff.