Aramco’s proved reserves are equal to the annual production divided by Aramco’s definition of annual depletion rate. Thus, total reserves are equal to 175Gb (3.5 Gb/2%), which is about half of their stated number of an extremely optimistic 359 Gb.

Finally, assuming that total reserves are 175 Gb and that these reserves are produced at a conventional depletion rate of below 5.5%/year, the oil production rate of Saudi Arabia is forecast to Dec 2020.  This forecast shows that production follows an exponential decline curve down to 4.5 million barrels/day in Dec 2020 and that it is highly likely that the world's crude oil and lease condensate production has passed a peak of 74.2 million barrels/day on May 2005.