Workover well control. Part 5. BOP equipment controls downhole pressure. [Blow-out preventers]

To control kicks and prevent blowouts, many factors of workover well control must be mastered. One of the more important parts is the proper selection and use of the equipment for pressure control. This equipment encompasses not only the production trees and surface blowout preventers but other items such as the mud monitoring equipment, degassers, and the mud mixing systems. When all of these systems are functioning, proper procedures can be executed simply in efforts to maintain control of the well and prevent blowouts. Annular preventers prevent or control formation fluid flow in the annulus of the well bore. These preventers include as components the spherical, pipe and/or blind rams, and spools. Each is discussed separately since their methods of operation vary.