The thread connection's root fillet radius of 0.038$ size is the greatest weakness of the API NC type joints and thread. During the slimehole drilling, especially in the deep and ultra-deep gas well, ...

A compression test conducted on a 7 5/8-in., 39-lb/ft P-110 casing joint buckled the pipe body rather than the connection. The test, conducted by Grant Prideco for Shell Offshore Inc.'s Brutus oil and ...