Assistant driller’s chair
25 July 2017
Back-up tong
25 July 2017

Annular blowout preventer

A type of BOP that uses a shaped elastomeric sealing element (“packing element”) to seal the space between the tubular and the wellbore or an open hole. There are no mechanical locking devices and, unless it is designed for wellbore assist close, it must have hydraulic pressure to remain closed.