If you fill a vertical pipe with water, the weight of the water produces pressure at the bottom of the pipe. That’s why we have water towers. A typical water tower is about 100 feet tall and produces about 40 to 50 pounds of pressure at ground level.
Imagine if you could build a water tower 10,000 feet (2 miles) high. The pressure would be 4,000 to 5,000 pounds. A deep well is like a tall water tower. The pressure at the bottom is equal to about half a pound a foot for each foot. That is the kind of pressure it takes to fracture rock layers. Deep disposal wells create that sort of pressure in the rock without the help of pumps because of the sheer weight of the water poured in at the top. Unlike the fracking process which last hours or days, the disposal well pressure is unrelenting. Over months and years and decades and centuries it is still there. The consequences are unpredictable. But Oklahomans have a pretty good idea what some of them are.
Think about a hydraulic jack. A small piston or pump produces a high pressure per square inch. My travel trailer weighs 12,000 lbs. Yet I can lift it with a little bottle jack. (Click the picture to learn how it works.)
The deep well shaft is analogous to the pump part of the jack. The miles of subterranean porous rock surrounding that well are like the lifting piston. The drilling company would like us to believe that nothing will happen when they add tons of polluted frack waste water to the well. Good luck with that. Their little company, all its owners, and all its employees may be long dead, but that well will still be there trying to lift the miles of earth around it.