دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: the speed reached by an engine or rotating system that corresponds to a resonant frequency of the engine or system. Often, in combination with power impulses, critical speed can cause damaging shock waves.

n: The rotary speed leading to cooscillation of drill pipe under any bit load.

n: weight placed on the bit that results in tension on the drill string, which causes the mill string to vibrate at tile rotary speed being used. A drill stem operating with critical weight and at the critical speed for that weight will have stresses develop that cause very rapid failure.