Subsea BOP dropped on the seafloor Complement
Main cause: Riser failures (Balljoints; Telescopic joint bolts failure, 1993¸ Vortex Induced Vibrations VIV –Rx: Helical strakes, K/C lines helically disposed, …)
1980 – Off Norway Pentagone 89 “Alexander L. Kielland” turned turtle, 123 killed. Misuse of 1 of the 2 false legs. ssBOP drop.
(1984 The above BOP was fished and reused on ODECO´s “Ocean Voyager”)
1982 Pelikan, off Tunísia. Slip joint failure: ssBOP on seafloor, fracturing subsea low pressure wellhead.
1982 UKOOA Ageing of BOPs tests
1983 Deep Sea SAGA Drop ssBOP, fished in 3 pieces
1984? Discoverer Seven Seas ELF, ssBOP adding Vetco Tie down Rods
1985? IADC/SPE 23901 Subsea BOP inspection, CHEVRON
1985 Exxon´s 18 ¾” 15K BOP test results
1985 ssBOP incidents, SINTEF Norway
1986? NIT (Norwegian InstituteTrondheim)
1987 ssBOP Reliability, SINTEF
1991 December SPEDC Sintef report
1994 Shell UK BOP QRA?
No track records of such
incidents to my knowledge, reason as I understand is that stakeholders were/are shy about it.
I can share the publication reference below which explains briefly cause of a lost BOP case but more interesting is about how it was recovered.
I was involved on this 1999 case on the Operator’s side as drilling superintendent when the lost BOP incident occurred.
This paper written by the drilling contractor is unique to my knowledge and really good as basis approach for any recovery attempt.
I take the opportunity to congratulate Paul Contarini at Al for their outstanding leadership in this case. THANKS Paul!
SPE/IADC 67808 - Pride Africa - Successful BOP and Riser Recovery Offshore Angola
P.Contarini, A.Zanchetta, P.Jeannet, M.Choquet, D.Sauteron, J.L Puyaubran/Pride Foramer-Sonamer, T.Duhen/Pride Int'l