دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a heavy, thick-walled tube, usually steel, used between the drill pipe and the bit in the drill stem to provide weight to the bit.

n: A heavy, thick-walled steel tuve that provides weight on the bit to improve penetration rates. A number of drill collar may be used between the bit and the drillpipe.

a very heavy wall pipe used to add weight over the bit during drilling.