So how do we calculate the R/P ratio for different countries? Usually, it is calculated at the end of any years when the remaining reserves are divided by the production in that year when the result is equivalent to the length of time for those remaining reserves that would last if production was supposed to continue at that rate.
The following graph clearly shows that the Middle East, CIS, and Africa are the top three contenders in the R/P ratio across the world. Also, as compared to North America, South & Central America holds a higher R/P ratio.
Source:- BP Statistical Review of World Energy 2020.