Oil is supposed to be non renewable resource but it's too important for many to abandon. Coal and kelp just can't meet the energy demands and building massive farms for it is isn't possible for many so those people use oil, however it doesn't Regen and it'll be harder and harder to get.

I have seen chunks gets regened and terrain rolled back but the oil doesn't so if oil is regenerated it shouldn't apply to the terrain as far as I know, I could be wrong.

I propose the oil in the oceans should get regenerated bc it's not as accessible on land so the over flooding of oil issue won't be there.