Can We Use a Thread-Making Machine to Seal a Leaking 20 Offshore Pipe?

[jackmell]

Hello. May I ask if we have the technology to run a thread-making machine on the end of that 20" pipe in the Gulf leaking oil and then screw a 20" cap on it? Is there even a commercially-available 20" threader? Largest I've seen is 6". Granted the oil pressure would initially prevent putting the cap on, but the cap could actually be a 20" valve (with threads), that is initially wide open, then screw it on, then turn the valve off. Even if it was cross-threaded being put on, that would still have probably been satisfactory.

Have to cut the end nice and square, and have a nice straight section of it to run the threader. Was this even considered? Certainly seems doable in hindsight although perhaps they initially thought that would have taken quite a bit of time.

Another question about it: what is the minimum number of threads we would have to put on this pipe to hold the valve sufficiently? I'm thinking run the threader just five times around the pipe would be enough. Maybe as few as three would do it.

Also for the uninitiated, the threader is usually an open device, kinda' like a donut with teeth on the inner surface to cut threads into the pipe so I don't think the gushing oil would interfere with the cutting action once the threader is placed on the pipe.

 

[Baluncore]

Cutting the thread might just be possible, as would screwing on a 20” open gate valve, then closing the valve. But it would be difficult and dangerous as water is induced to circulate strongly where the escaping fluid enters the sea water from the pipe.

Threads are not usually employed on large diameter pipe. Bolted flanges are preferred above 6 inches because one diver can tighten the bolts without tangling lines or being swept away.

It would probably be easier and safer to clamp a pipe extension with an open valve onto the open pipe. That would move the exit turbulence away from the connection while the seal and clamp were completed. Once the joint was secure the valve could be turned off.