Friend of a friend died awhile back snubbing on top of a pulling unit. Damn near a half-mile of casing came out of the hole and almost took out everyone on location. A BOP ain't stopping that shite.
Nope. I've only seen it happen once. We had the TIW in and the annular closed on a kick. Well started pushing the pipe out the hole The TIW wedged in one of the derrick girts and the pipe still kept coming out and curled all over the pipe rack like spaghetti. They were eventually able to get the pipe rams shut along with the annular and that held.
After the well was dead they still had all that gas filled pipe all over the rig. To get it off they would freeze it with nitrogen and cut it at the frozen section. The ice would temporarily hold the gas in.
I was on a rig in ST after a perf job and we took a hell of a big kick. The entire choke manifold was covered in ice all the way up to the top of the bleed off line in the derrick. Straight clear LNG was coming out the choke and down the ditch. There weren't many people sleeping that night.