I have been keeping up with some interest with the situation in the Gulf. All attempts to staunch the flow of oil from the damaged riser from the well have failed, and as we speak, another attempt is being tried, cutting off the riser to find unbent metal and essentially pushing a straw with a cork on it into the interior of the riser.
That might work, but I suspect that the pressure from the methane dissolved in the oil will make it difficult. Perhaps if a pair of flanges could be welded onto the riser and the pipe, and then bolted down to secure them, it might work.