There are 1.65 trillion barrels of proven oil reserves in the world as of 2016.
The world has proven reserves equivalent to 46.6 times its annual consumption levels. This means it has about 47 years of oil left (at current consumption levels and excluding unproven reserves).
This means that the oil is going to run out in our lifetime
Source/more reading: https://www.worldometers.info/oil/
Update: It is infact not true (or just partially true), because it only considers already known oil reserves that can be pumped out with current technology.
There is more oil that can potentially be used as technology and infrastructure advances, so the estimate of 50 years is wrong.
For the correction thanks to Cephalotrocity@biglemmowski.win (their original comment)
I’ve heard this for my whole life. Oil runs out in X years, until they develop affordable ways to dig deeper and get at more
Cheapest oil runs out in x years. Mid cost in y years. Expensive in z years. Then we get into “manufactured” oils.
Oil isn’t going to run out, it’s just going to get more expensive.