This could be bad.
And everyone: you can stop taking about BP pumping cement into the hole to plug the well. I know it’s difficult for most to envision what’s going on down there. But this isn’t a simplification of the situation: you have a pipe sticking straight up the air and it’s flowing 10 gallons per minute out the top. You stick a tube down the pipe and start pumping cement. Question: how long for the cement to harden? Answer: never. The cement is going to mix with the water and flow out the end of the pipe. Honest...I didn’t dumb down this example. That’s exactly what would happen if the pumped cmt down the blow out if it were still flowing. No one has ever set a cement plug into a flowing well in the history of the oil business. But you can shove a packer down a producing csg string and stop or at least slow a flow considerably. But can’t shove a packer down this hole: can’t get it through the BOP. And if you could there’s drill pipe in the way.
http://www.theoildrum.com/node/6516
I just finished watching most of the BP news conference at 5:30 and was struck by the fact that the rep kept talking about including “bridging material” in the mud mixture when pumping is resumed later tonight. This leads me to believe (I have no way of knowing this for sure) that they have determined that they are in fact loosing mud to the formation as well as out through the leaking BOP. If that is true then the location and size of that down hole communication will determine whether or not this procedure will, in the end, succeed or fail.
Being retired and as far away as I am from the operation and having no better information than anyone else here, I am only guessing at this point and need to make that plain.