The link above will help explain how the relief wells get close. But even when they got down to 20, even 5 foot of separation, they are still separated by 20~5 feet of rock. There is no way to test the integrity of the original casing at that point. Magnetic sensors are used to detect the casing and used to help with the steering, but it doesn't give pressure, flow or any data like that.
This following is the transcript that went with the above slide show presentation on June 28th.
The link above will help explain how the relief wells get close. But even when they got down to 20, even 5 foot of separation, they are still separated by 20~5 feet of rock. There is no way to test the integrity of the original casing at that point. Magnetic sensors are used to detect the casing and used to help with the steering, but it doesn't give pressure, flow or any data like that.
I went to the link. Surely the magnetic sensor can give a rough idea if the gusher's steel well casing has been abraded to less thickness.
From the diagram it looks like the relief well will not be punching through the gusher well. It will just pump in mud like crazy when it finds the end of the gusher well casing and hopes the mud will crowd out the oil surging upward