A SYSTEM FOR CONTROLLING WELLBORE PRESSURE DURING PUMP SHUTDOWNS

摘要

The present disclosure contemplates a method and apparatus for maintaining well pressure control despite fluctuations arising due to mud pump speed changes during startup and shutdown of a mud pump. More particularly, the present disclosure relates to a method and apparatus for closely coordinating changes in mud pump speed, or the flow rate of drilling mud, with the operation of choke valves for the maintenance of a constant drilling fluid pressure during drilling breaks such as the addition of drill pipe sections to the drill string.