Galling resistant drill pipe tool joint and corresponding drill pipe

• Main Authors: Ono, Tatsuo, Kobayashi, Nobuo, Sato, Nobuhide, Yoshida, Motohisa, Sakura, Koji, Kuwano, Takeshi, Fukui, Toshihiko, Narikawa, Tomoyuki
• Format: Patent
• Language: English
• Published: 01.03.2018
• Subjects: APPARATUS THEREFOR; BLASTING; CHEMISTRY; EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; ELECTROFORMING; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; ENGINEERING ELEMENTS AND UNITS; FIXED CONSTRUCTIONS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; JOINTS OR FITTINGS FOR PIPES; LIGHTING; MEANS FOR THERMAL INSULATION IN GENERAL; MECHANICAL ENGINEERING; METALLURGY; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS; PIPES; PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTIONOF COATINGS; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; THERMAL INSULATION IN GENERAL; WEAPONS

A drill pipe tool joint comprising:a pin including a male threaded portion at an outer surface; and a box including a female threaded portion at an inner surface, the female threaded portion to be screwed and fastened to the male threaded portion in a contacting zone consisting of a male threaded contacting surface and a female threaded contacting surface, wherein at least a portion of the male threaded contacting surface or a portion of the female threaded contacting surface is a surface layer consisting of a hard metal and respectively at least a portion of the female threaded contacting surface or a portion of the male threaded contacting surface is a surface layer consisting of a soft material and where said both surface portions are contacting surfaces after screwing.