a) blowout preventers (BOPs);
b) choke and kill lines;
c) choke manifolds;
d) control systems;
e) auxiliary equipment.
The primary functions of these systems are to confine well fluids to the wellbore, provide means to add fluid to the wellbore, and allow controlled volumes to be withdrawn from the wellbore.
Diverter and rotating head systems (rotating control devices) are not addressed in this standard (see API 64 and API 16RCD respectively); their primary purpose is to safely divert or direct flow rather than to confine fluids to the wellbore. Procedures and techniques for well control are not included in this standard.