It is?
Some theories have oil being made by organic life over hundreds of millions of years (like coal), others say it's only over a few hundred thousand years, still others have it being created with the earth itself.
One of the few things we know for sure is that the quantity of discovered available oil reserves world wide has been increasing faster than its use, which is more than we can say for geothermal sources..
Oil = lymph.
Thomas Gold's books are a great starting point.
It's important to understand as a foundation for undoing all the other lies.
See > Robert Newmans History of Oil on youtube.