You are correct! I call it earth’s blood. I also think it functions like a hidraulic shock absorber, cusioning shifting land, and perhaps causing shifts like magma does. Its hard to say how long it takes to make oil in the earth, but as long as it isn’t used up faster than it can be made, it will last a long time. It’s renewable.
Dang erf is always tossin’ a monkey wrench in to things.
I would believe it fairer to ascribe the shock absorber role to the magma, which is hot enough that oil in contact with it would decompose even with no oxygen available. The oil we know of would exist in pools in cooler regions of the earth’s crust, closer to the surface than is the magma. Not a literally infinite amount, but perhaps lots, lots more than anybody has dreamed of. Well enough to tide humanity over until the Lord ends history.