The world production of conventional oil was projected parabolically using preliminary data posted on the Web by the U.S. Geological Survey in advance of the formal publication of the Year 2000 Assessment (DDS-60) of undiscovered oil resources. This major study was released at the time of the 16th World Petroleum Congress held in Calgary, Alberta, 11-15 June 2000. This technique was employed to estimate the timing and magnitude of the peak in conventional oil production for the world as a whole. The Mean Value of the assessment was employed in the parabolic calculation to derive two boundary cases due to the uncertainty concerning a large quantity of oil termed `reserves addition.' Oil in this category was assumed to contribute to output only after the peak has passed at one extreme (Case 1) and to be continuously available throughout the production period at the other (Case 2). The actual production is likely to lie between these limiting cases.

In two sensitivity tests, oil production based on the smaller oil resources at 95% probability was calculated in Case 3 and the larger resources at 5% probability in Case 4 which represent two extremes of the assessment values. In Case 1, world conventional oil production peaked at 29.38 gigabarrels (GB) per year in 2017.1; in Case 2 - 31.1 GB/yr in 2026.9; in Case 3 - 28.53 GB/yr in 2012.1; and in Case 4 - 30.60 GB/yr in 2024.1. Cumulative and per capita data were also calculated from these four projections.