I would weld a flange around the outside of the pipe a bit below where it's broken. This shouldn't be a problem since there's no oil under pressure coming out there.
Then I would make a contraption consisting of three parts:
1) similar flange to the one on the ocean floor that can be bolted on to the one welded on the pipe
2) a cylinder welded on top of the flange
3) some sort of closing mechanism on top of the cylinder.
Get divers (or ROV's) down to attach the contraption to the pipe by bolting the two flanges together. This should be possible since the oil will just rise out of the cylinder, so the pressure of the oil shouldn't be a problem. When the contraption is secured activate the closing mechanism.
The only requirement here is that you can weld something onto the pipe below where the leak is. I don't know whether that's possible at that depth though.
I thought the BOP was 30,000 feet down or is that the length of the bore hole? I've been fairly ignorant as to paying in depth attention to the whole debacle.
IIRC, from memory, the well head is at circa 5200 feet and the borehole extends from there circa 18,200 feet further, to a short distance below the intended production zone. (I may be mis-remembering.)
if mating the pipe with something is too hard, what if the flange were strung with some kevlar cords which loop over the broken opening. keep doing the junk shot but with bigger junk that'll get stuck at the what is now a kevlar net attached to the end of the pipe.
or seems like there should be a safety robot that grabs the end of a broken pipe, attaches a flange, then knits (like how they make socks) a pipe on the way back to the surface
Then I would make a contraption consisting of three parts:
1) similar flange to the one on the ocean floor that can be bolted on to the one welded on the pipe
2) a cylinder welded on top of the flange
3) some sort of closing mechanism on top of the cylinder.
Get divers (or ROV's) down to attach the contraption to the pipe by bolting the two flanges together. This should be possible since the oil will just rise out of the cylinder, so the pressure of the oil shouldn't be a problem. When the contraption is secured activate the closing mechanism.
The only requirement here is that you can weld something onto the pipe below where the leak is. I don't know whether that's possible at that depth though.