There's a thing when you get to only about a mile or two down and happen to strike vastly rich oil reserves. Then you're a billionaire already so what's the incentive to continue going all the way?
If ICE vehicles fall out of fashion, oil will still be immensely useful for chemical refinement but with nowhere near the demand that burning it has. It'd still be a fortune but a slow one rather than a "drain it as fast as possible to print money" kind.
Digging deep holes for geothermal guarantees the industry a future at this scale when the move to electric inevitably happens. The alternative is for them to pass up the opportunity and solar, wind, and nuclear to eat their lunch.
What is the probability of oil getting in the way of an arbitrary hole whose position is picked for other reasons. Such as proximity to large population.
