I'm no expert, but it seemed extremely unlikely to work to me. The BOP is damaged, they're working at extreme depths, and the leak is very very large.

There's a long thread of comments at The Oil Drum with informed commentary on the various issues - http://www.theoildrum.com/node/6522

Here's an earlier post on what is believed to have caused the blowout - http://www.theoildrum.com/node/6493

They're now going to try the "LMRP" which sounds risky to me, but they've got to keep trying... http://www.theoildrum.com/node/6523

[...]

Heading Out's Thoughts on the Press Conference

BP and Admiral Landry just help a Press Conference in which they said that, based on a decision 90 minutes ago, by the “best and brightest minds” that it was time to move on the next option, the Lower Marine Riser Package (LMRP). BP was unable to block sufficient flow out of the well to make the injection of cement possible, and thus to kill the well. They had made, I believe he said three attempts to inject material (the junk shots) without being able to get that material to block the passages through the Blow-Out Preventer (BOP) . (Unfortunately I missed a large part of his opening remarks, and thus have only the question response to go on at present). The volume of mud used did not appear to have changed from earlier reports at some 30,000 barrels.

Mr Suttles said that they had given the technique every chance, but could not get it to start to provide an effective seal. They had, however, determined that the majority of the pressure restrictions to the flow of oil was coming from some resistance within the well itself, and from the BOP. Since the riser above the BOP was not contributing much to the resistance, and thus to control of the oil flow, the next plan is to remove it, using a band saw device (of which pictures will be available) and then to lower the LMRP onto the existing BOP. They intend cutting the surface that the LMRP will sit on flat, so that it will give a good, but not perfect seal. Thus there will be some leakage around the joint, and they will monitor that and use dispersant as appropriate.

The new change should take somewhere between 4 and 7 days to implement. The assembly, which has been constructed, and is not the Top Hat assembly built earlier, to fit on the bottom of a riser. Flow of oil from the LMRP will rise up a 6 7/8 inch drill pipe within the riser (the same size as the one currently fitted to the RIT). The riser will also carry hot water down to the LMRP to protect against the formation of hydrates.

He noted that their inability to stop the well “scares everybody” but is reasonably confident (no success percentage estimates) that this will collect the majority of the oil and gas. Because they do not know the flow path of the oil below the seabed it is difficult to estimate what is actually going on in terms of oil path below the BOP. Thus they are, again, trying something that has never been done before, but expect, based on the RIT, that it will work.

[...]


Every day that passes erodes the BOP and piping more (grit and rocks in the oil and gas). As bad as it is, it can still get much worse.

Cheers,
Scott.