How did oil last so long?

Question

It is known there are more than one kind of bacteria that degrade petrleum. This being true, how could the componenets of the oil not be digested by bacteria before it was stored in the earth?

Answer 1

Was never "Stored" in the earth it became oil from organic material deep in the earth where there is no "that we know of" bacteria or any life.

Answer 2

The places where oil formed were thought to be anaerobic because of so much organic matter falling down into the sea.  There are conditions like that in currently in parts of the gulf of Mexico.  There is so much plankton that bacteria use up all the oxygen and there is not enough at the bottom to digest the molecules.

Answer 3

because of d**k and balls.