HOW is there so much crude oil left?

Question

In grade school I remember learning that the creation of crude oil in the Earth’s crust was a rare event. How was so much created?

In: 19

Answer 1

It is rare, and in any given year only small deposits (i.e., deposits that would become oil in the future) were laid down. However, the Earth is very old, and over time those rare events accumulated. We have to use pretty sophisticated science to find oil, you can’t just randomly dig a hole in the ground to find it.