THREADED JOINT FOR OIL WELL PIPE

• Main Authors: YAMAMOTO, HIDEO, NAKASUJI, KAZUYUKI
• Format: Patent
• Language: English; French
• Published: 24.01.2006
• Subjects: BLASTING; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; ENGINEERING ELEMENTS AND UNITS; FIXED CONSTRUCTIONS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; 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; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; THERMAL INSULATION IN GENERAL; WEAPONS

A threaded joint for an oil well pipe, characterized as having a screw part and/or a metal-metal contacting part with no screws which have, formed thereon, 1) a lubricating coating of an inorganic polymer having a skeleton of M (metal atom)-O (oxygen) and containing a solid lubricating agent dispersed and incorporated therein, 2) a phosphate coating and the above lubricating coating of an inorganic polymer, 3) a Cu plating layer, and the above lubricating coating of an inorganic polymer or a lubricating coating of a resin containing a solid lubricating agent dispersed and incorporated therei n, or 4) the above lubricating coating of an inorganic polymer or the above lubricating coating of a resin, and a rust-inhibiting coating containing an alkali metal or alkaline earth metal salt of a carboxylic acid. The threaded joint for an oil well pipe can prevent the occurrence of galling in repeated make-up and break-out operations and at the same time secure high oil- tightness, with no use of a liquid lubricating agent such as a compounded grease.