coated drill rod unit for underground rotary drilling operations, and method for reducing friction on a coated drill rod unit

摘要

Provided are drill stem assemblies with ultra-low friction coatings for subterraneous drilling operations. In one form, the coated drill stem assemblies for subterraneous rotary drilling operations include a body assembly with an exposed outer surface including a drill string coupled to a bottom hole assembly or a coiled tubing coupled to a bottom hole assembly and an ultra-low friction coating on at least a portion of the exposed outer surface of the body assembly, wherein the coefficient of friction of the ultra-low friction coating is less than or equal to 0.15. The coated drill stem assemblies disclosed herein provide for reduced friction, vibration (stick-slip and torsional), abrasion and wear during straight hole or directional drilling to allow for improved rates of penetration and enable ultra-extended reach drilling with existing top drives.