Where does oil come from?
Oil is commonly believed to come from decaying vegetable and other organic matter.
A new voice says it comes from METHANE. Apparently Methane, when super hot, and under immense pressure, as it would be far below(and deeper than known old vegetation,etc.), becomes molecularly re-structured. – Into OIL.
A further production from this oil is natural gas.
This oil, and gas, is constantly bubbling up into pockets, thus continually replenishing itself.
Therefore we should not worry unduly. Just give it chance to re-accumulate.
I hope this new voice is right.