RECENT SITUATION AND FUTURE OF ANTI-GALLING TECHNIQUE FOR API ROUND THREAD

The thread galling is a familiar failure of oil tubing and casing as an object of petroleum and metallurgical researchers. The galling failure of oil casing and tubing connection thread, and the anti-galling technique are discussed and analyzed. The galling failure mechanism, optimized parameters of pipe thread, thread grease and surface treatment for coupling thread, special nipple, the operation standard of makeup and breakout are summarized. The existing problems are pointed out, and the research direction is discussed.