The original cement seal to close off the well would have been placed in the hard, “good” strong rock above the oil producing rock. (The good, hard rock that has kept that oil from floating upwards and in place for the last 100 million years or whatever).
That seal is what blew because BP rush things (IMHO from what I have read). One (or both) of the “relief” wells will be used to pump heavy mud and then cement into and around the well in the good, hard rock. I wonder if the deeper relief well might “suck” to reduce the pressures, and a shallower well could “blow” the mud and cement in?
The relief wells can use directional drilling, and they even have magnetometers now to guide the new wells to within inches of the existing iron casing.
The nuke option used by the Russkies was before this accuracy was available. They drilled down into the hard rock above the reservoir and got at close as they could to the bad well. Then set the nuke off to shift the hard rock around to block the bad well. I suppose one could be hundreds or thousands of feet away and it would work. (Or the 4 out of 5 times the russkies SAY it worked!)
They will get this well stopped. The Gulf, in time will recover. Maybe in one fishing season, maybe in 20 seasons. (I think it will be lower that feared).
And, Obama will use this terrible accident to his full advantage. (See my tagline.)
Where did you get the information that there is good strong rock down there? From what I have read, there is no rock in the seabed nor down the length of the pipe. Did I miss something?