Videosifts own @arvana posted this :)
Trying to cap the pipe is inherently difficult because of the pressure pushing the cap off. Ted Funger had the idea of stopping the leak with a cone-shaped plug that can drop INTO the end of the pipe, just above the blow out preventer. We've tested it at a small scale with a hose pipe, and it works very well; it should just take a bit of engineering analysis to scale it up.
