Good point. But hydro-fracking involves subjecting well casings and grout to a good deal more positive pressure than simply pumping oil, does it not?
If it leaks during the hydro-frac process, I suspect it is going to leak afterwards during production.
I don’t see the chemicals that exist in the initial process a greater problem than the years of oil/gas that follows.
No, the casing isn’t under pressure.
There is tubing inside the casing the fluid flows through and at the bottom of the tube there is a packer that keeps the fluid from coming back up the casing and only going through the perforations into the production zone.