Annular blowout preventer

The annular blowout preventer (also called a universal blowout preventer or ball blowout preventer) is a core well control device in drilling well control systems. Compliant with API 16A and GB/T 20174 standards, it is installed at the top of the wellhead blowout preventer assembly. Relying on the radial contraction of the rubber core, it can seal drill pipe, tubing, and casing of different sizes, as well as the empty wellhead, achieving a soft seal under various operating conditions. It is a key piece of emergency well control equipment. Main functions:
1. Sealing various tubing strings and empty wellheads, including drill pipe, drill collars, tubing, and wire ropes of different outer diameters, without requiring replacement of seals;
2. Allowing for the tripping of drill strings under pressure during tripping operations, and also enabling a complete seal of the wellhead when there is no tubing string in the well, preventing blowouts.
3. In conjunction with choke and kill operations, after closing the annular blowout preventer, kill and choke measures are implemented through the gate blowout preventer side door or kill manifold, establishing a circulation channel to control well pressure.
4. Emergency safety protection: In the event of overflow or well kick, the well can be quickly shut off hydraulically to achieve emergency well sealing; it can form a multi-level well control barrier with the gate blowout preventer.