What happens to an oil field after the oil is pumped out? Does it just leave a void/cavern? Isn’t it today to leave that because it could collapse?
In: Engineering
Isn’t it today? Yes it is today. Ow my brain hurts!
All the other explanations are good, but are missing the small point that when oil is pumped up to the surface, the liquid coming out is maybe 10 percent oil and 90 percent salt water. The oil is separated out and the saltwater is pumped back underground.
Oil isn’t in a big cavern underground. It’s seeped into the rock, and when a hole is drilled through the pressure of the Earth compressing the rock squeezes the oil out. So when there’s no oil left, there’s still plenty of rock down there.
In some formations depleting the oil/gas can cause some ground subsidence, but usually nothing dangerous.