[Ernest_at_the_Beach]

two drill strings

[justa-hairyape]

Saw a comment on the Oil Drum that sometimes when the drill pipe gets sent upward due to a blowout, it can break at points. Where it breaks there can be and area where the broken pipe gets pushed up around the other section it broke free from. So two drill strings could be one that was broken in two and overlapped due to the incredible forces of a blowout. At any rate, if the shears did fire and fail to completely close the pipe, the main pipe above the wellhead within the BOP has a compromised integrity.