دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a drilling tool that, when placed in the drill stem just above a roller cone bit, delivers high-frequency percussion blows to the rotating bit. Hammer drilling combines the basic features of rotary and cable-tool drilling (i.e.. bit rotation and percussion).

n: a kind of satellite drilling tool which is installed in bottom of the pipe and the top of cone bit and which can create high frequency impact effect