Rickover said all kinds of stuff. Some of it was even true.
Let's check:
World proven oil reserves: 1137 billion barrels
Oil production/consumption per year: 17.6 billion barrels
Time to deplete reserves at current rate of consumption: 64.6 years
According to a little internet research I did, most oil has been formed since the pre-Cambrian period which ended 542 million years ago.
542 million / 64.6 = approx 8.4 million years to produce oil consumed in one year
So Rickover at least had the right order of magnitude.