In preparation to pick up a 3 ½” Kelly, the 5 ¼” Kelly and swivel connections were broken with pipe in the hole to lend stability to the process. The 5 ¼” Kelly was then placed in the rat-hole (Kelly shuck) with broke connections until such time that it could be laid down and the 3 ½” Kelly could be picked up for the next drilling interval.
Prior the operations getting to a point where the 5 ¼” Kelly was going to be laid down, a change of crews occurred. The new crew began preparing to test Blowout Preventer Equipment and they were having difficulty getting the cup tester to set in the casing below the BOPE. So they picked up the Kelly to help push the cup tester down into position. Not knowing that the Kelly connections were broken, the driller activated the Kelly spinner to align the cup tester with the casing opening. The swivel’s left handed threads backed out of the Kelly which separated at the break and the Kelly fell to the off-driller’s side of the floor onto the air hoist and sample house. No injuries resulted.