硬岩破岩滚刀密封失效原因分析与结构改进

Causal analysis on sealing failure of hard rock broken cutter and structural improvement

硬岩钻井破岩使用的大都是球齿滚刀,随着井深的增加,滚刀所处的工作环境压力随之增加,当滚刀旋转密封耐压强度小于工作环境压力时,密封失效,洗井液进入滚刀油液密封腔内部,洗井液中含带的岩屑会导致滚刀轴承的破坏。针对某型国产滚刀,研究分析其密封失效的主要因素,提出改进其密封结构的技术措施并加以改进,改进后进行的滚刀密封压力试验结果表明,其旋转密封效果得到改善,较原滚刀使用寿命显著提高。

The ball-toothed cutter is mostly used for hard rock breaking. With the increase in drilling depth, the pressure of the cutter rises. While the rotating sealing compression strength of the cutter is lower than the surrounding pressure, the sealing fails, then the flushing fluid enters the sealing chamber of the cutter. Thus the rock debris in the flushing fluid damages the bearing of the cutter. In the paper, a home-made cutter was taken as the study object, main factors leading to its sealing failure were studied, and measures to improve its sealing structure were offered to conduct improvement. The results of the test for the sealing pressure of the improved cutter showed the rotating sealing effects improved and its service lifespan enhanced remarkably.