دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a special bit nozzle, often used on large bits, that lengthens the nozzle and therefore places the jet of drilling fluid exiting the nozzle close to the bottom of the hole. With large bits, where regular nozzles can be relatively distant from the bottom of the hole, the cleaning power of the jet of drilling fluid may be lost because the velocity, or speed, of the jet diminishes rapidly after it exits the nozzle. By extending the length of the nozzles, the jets are placed closer to bottom for maximum cleaning.

n: the spray head which is longer than ordinary spray head