دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

v: to lower the bit continuously or intermittently by allowing the brake to disengage and the drum to turn. The feed-off rate is the speed with which the cable is unwound from the drum.

n: The act of unwinding a cable from a drum. Also a device on a drilling rig that keeps the weigh on the bit constant and lowers the drilling line automatically. See also Automatic driller.