دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: an expendable substitute device made up in the drill stem to absorb much of the wear between the frequently broken joints (such as between the kelly or top drive and the drill pipe). See kelly saver sub.

n: The sub between the drill string ,which be used to decrease the wear when make up and breakout.