Development and application of fiexible sucker rod anti-attrition unit

In recent years, many anti-eccentric wear technologies have made some achievements in Jidong Oilfield. In the highly deviated wells with sucker rod pump, however, the pump inspection cуcle is short and the operation and material replacement cost are high. To solve these serious problems, the mechanics model of rock rod string was established to analуze the force. It is shown that the friction applied on the sucker rod string can be reduced by replacing the conventional sucker rod with the fiexible sucker rod. Then, the fiexible sucker rod anti-attrition unit was developed. Its upper and lower parts can rotate relatively within a small angle. After the fiexible sucker rod anti-attrition unit is installed on the sucker rod string, the sucker rod string is accordant to the axial direction of tubing string in the process of movement, and consequently the con fiict between the sucker rod and the tubing is alleviated and the friction applied on the sucker rod is reduced. Field application results show that after its technologу is applied for 300 daуs, the tubing and the sucker rod are shortened bу 0.15 m and 0 m, respectivelу from the original length of 200 m due to eccentric wear. It is indicated that the eccentric wear of sucker rod and tubing and the pump inspection frequencу and operation and material replacement cost caused bу the eccentric wear are reduced significantly.