دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a special well-control tool made up in the drill pipe usually just above bubble, of gas enter the annulus, the bubble chopper allows mud in the drill string to be diverted into the gas bubble by means of an opening, or port, in the tool. The mud from the drill string mixes with and spreads out the large gas bubble so that the gas cannot expand to a great extent as it nears the surface. Reducing the amount of bubble expansion reduces pressure on the casing near the surface and thus minimises the chances of formation fracture and an underground blowout.