I caught a certain amount of flack from NPR about using an undergound nuclear explosive to seal this well. But the datum are well documented. At the depths we are talking about , a mile or so down a "relief well" a properly placed charge would seal the well and collapse the pipe to the reservoir.

www.cddc.vt.edu/host/atomic/images/enw77b25.gif


You might also be interested in :
http://www.livescience.com/technology/russia-nuke-gulf-oil-well-100512.html