دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: drill pipe that is manufactured with walls that are thicker than those in standard drill pipe. Special extnilength tool joints are attached to the heavier-walled tube. lYPically, 5-inch heavy wall ,.drill pipe weighs50 pounds per foot (75 kilograms per metre);5-inch conventional drill pipe weighs 19.5 pounds per foot (29 kilograms per metre). Also attached to the tube is a centre wear pad that protects the outside diameter of the pipe from abrasion. Heavy wall pipe is often used in the drill stem just above the drill coilars, in the transition zone between the stiffer collars and the more limber drill string, and in place of some drill collars to apply weight on the drill bit in smalliameter and horizontal holes. Sometimes erroneously called heavyweight drill pipe. Compare heavy- weight drill pipe.