[bert]

The effort will be made using the bop as an entry point below where the fallen riser connects. The weight of the drill mud will eventually overcome the pressure and can then be capped with some unnamed type of cement/concrete

[Steve Van Doorn]

No doubt about that a full size drill rig will work but that is going to take a long time to set up. My method would could be done in a week I would guess.

I would add one thing to my method... using that simple drill once you get it down to optimum depth then use the balloon and then the bell or long heavy pipe at the same time. I would also use some kind of hammer to force the pipe/bell down as far as possible.

if the balloon doesn't hold at all the bell might not either I would use the heavy pipe as a funnel to direct the oil to a tankers or something.