Applying blowout prevention concepts that have been developed for drilling operations to a completion/workover situation is improper in many cases. In fact, application of all rules required by drilling well control courses and manuals will result in dangerous situations on many workovers. Furthermore, the majority of class time in a typical well control school is devoted to minimizing surface casing pressure during a kick, a principle that has almost no application in a completion/workover situation.
There are at least sixteen key differences between workover wells and drilling wells that demand a different set of requirements for safe well control. These important differences continue to be revealed in the form of surprises as workover crews struggle to comply with a multitude of very strict rules, all of which have evolved from situations encountered while drilling. This paper will emphasize these key differences and will introduce an idea for replacing current Completion and Workover Blowout Prevention Specifications with just a few easily understood specifications based on the Barrier Concept.