| Oil-sucker rod coupling and oil tubing constitute sliding friction pair in the work state in the oil wells, meanwhile withstands corrosion and alternate load, which cause wear, corrosion and fatigue failure. With the exploiting of the oil deposit, the composite water cut of the oil wells is ascending drastically, the eccentric wear condition in oil wells is becoming worse and worse in most oil fields of China. Amount of maintenance work and the fabricating cost are ascending with the service interval of the wells becoming shorter caused by eccentric wear. Centering device and antiseptic wear proof coating are used for prohibiting eccentric wear, and the problems such as complex operation and environmental contamination exist with some effectiveness. In order to solve the problems of the side wear between the oil tubing and coupling in the oil wells, a 5kW transverse-flow CO2 laser is applied for laser cladding coupling and laser hardening the oil tubing inwall. The paper mainly studied the following three aspects of the partial rod and tubing wear issues:The change of the major organization after laser surface modification is studied; specimen's macro-hardness and micro-hardness are tested. The results showed: the organizational transformation hardening area is black and fine needle small amount of quenching martensite and residual austenite, ferrite white, continued to show a zonal distribution; Cladding is composed by theγ-Ni based solid solution and distributed on the mesh or the needle of the boride, carbide and silicid; ordinary tubing hardness is HRC24, the hardness of common coupling is HRC18.8; hardness of laser-enhanced processing pipeline inner wall surface is 1.6 times than the ordinary tubing; the coupling surface hardness of Ni35 laser cladding alloy is 1.95 times than ordinary hoop; The coupling surface hardness of laser cladding Ni60 package 30% WC is three times than the hardness of ordinary coupling; the hardness that is 0.46mm from surface of laser Cladding Ni35 hoop is the highest , 460HV0.3 around; The highest hardness of transformation hardening tubing is 550HV0.3 around, the depth of the surface with the distance larger, the hardness decreases.Rod wear under water is mainly studied. The wear test revealed that transformation hardening tubing and Ni60 package 30% WC clad hoopisthe better combination of friction pair, whether tubing or coupling trends in the overall wear is lower, and after five days of wear and tear ,the tubing phase hardened still exist in large numbers, lower wear rate, better wear resistance, then laser transformation hardening tubing with the Ni60 package 30% WC clad coupling interaction, the sucker rod friction's anti-bias mill capacity can be improved. It is showed that in the process of friction and wear, oxide film formed on wear contact layer constantly falling off, abrasive wear caused by the formation of wear debris, then between the rod and tubing wear is mainly abrasive wear, by SEM analysis.Rod abrasion performance under 3.5%NaCl is mainly studied. The abrasion test was found that combined with friction pair as a whole with the weight loss, transformation hardening tubing and Ni60 package 30% WC clad combination of friction pair coupling is better, sucker rod Friction's ability to prevent partial wear can be improved. The paper is validation obtained that transformation hardening tubing with the Ni60 package 30% WC coupling is the better combination of frictional pairs.
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