Anyone have a similar experience or possible explanation for the following: Trying to avoid leaving this an oilfield mystery.
13â…œ"68# N-80 BTC casing ran on semisub to 4350' in vertical hole section. Landed out and cemented with no issues. Bumped plug and began pressuring to planned casing test of 3500 psi. At 2100 psi the string jumped and pressure went to 0 psi. POH and found pin on 15”² pup joint below SS hanger had released from BTC coupling on 1st full joint of casing.
Exactly the same like what I encountered before...specially when I read that casing string jumped after bumped plug :). Hopefully this wont be your mystery of oilfield again....
In my case, casing string parted from the bottom of ECP which we incorporated into the casing string. No sign of any damage whatsoever on the bottom connection of the ECP.
After incident we sent that ECP to one of the machines shops who has a BTC gauge and that machine shop confirmed that the BTC was out of spec. Well... you can figure out the rest of story yourself.
Visually that BTC connection has no different with other BTC connections.