水力加压装置活塞密封失效故障诊断方法

Fault Diagnosis of Piston Seal Failure in Hydraulic Thruster

水力加压装置是以循环泵压为动力,把液体的压能转化为钻压的一种井下钻井工具,用于获得稳定的钻 压,解决跳钻问题,提高机械钻速、钻具寿命和钻井质量。该装置在现场应用中表现出了使用寿命差异大的问题,分 析其主要原因是活塞密封失效。采用压力诊断方法对水力加压装置的密封保持情况进行了诊断。通过对压力信号故障 诊断曲线的分析,以及对水力加压装置现场使用寿命的跟踪调查统计,发现了压力波动与密封情况的关系,验证了压 力信号故障诊断结果与工具现场使用寿命的相关性与一致性,进而采取了消除故障隐患的有效措施,保证了水力加压 装置的使用寿命。该故障诊断方法准确、实用,是一种较为有效的诊断方法,可推广应用于其它类似工具的密封诊 断。

A hydraulic thruster is a down hole drilling tool that transforms hydraulic pressure into weight- on-the bit （WOB） powered with pump pressure, which can achieve steady WOB to solve the problem of bit bouncing, increase the ROP, extend the working life of drill string and improve the drilling quality. Applications of such tools in oilfields show big working life difference. Analyses indicate thruster life is mainly decided by piston seal condition. Thus, the packing situations of hydraulic pressurization equipment is diagnosed by means of pressure-diagnosis method. After analyzing pressure-diagnosis curves and field working life of such device, relation between pressure fluctuation and piston packing situations are detected, which validated the relativity and coherence between pressure-diagnosis results and field working life, and then effective measures to eliminate hidden troubles are employed which guarantee working life of thrusters. Being accurate and practical, the diagnosis method is a effective one, and can be applied for other similar packing diagnosis.