提高MWD仪器在特深小井眼水平井测量可靠性的方法

Methods to improve MWD measurement reliability in ultra-deep horizontal slim-holes

顺北油气田油藏深度7 300~8 600 m,井底温度160~210℃,钻井作业定向仪器故障频繁。高温环境下MWD仪器测量影响因素主要包括仪器自身因素(脉冲及探管)及外部施工环境因素(振动、操作、腐蚀等),而后者可以通过采用适当的工艺措施进行改善。为提高仪器测量可靠性和定向轨迹控制时效,从振动、抗温、操作及工作环境等方面分析了不同因素对仪器信号质量的影响,提出了针对性技术措施。研究及应用证明,通过优化动力钻具尺寸、定向剖面、脉冲发生器间隙值、排量等工艺技术,可以利用合适的工艺措施提高高温MWD测量可靠性,有效降低特深定向/水平井仪器故障率,提高特深水平井轨迹控制效果。SHB1-4HCH等井应用上述工艺措施取得了明显的效果,进一步验证了改进措施的实用性,为同类区块的作业提供了有益的借鉴。

The oil reservoir depth of the Shunbei oil and gas field is 7 300~8 600 m,associated with bottomhole temperatures of160 ℃~210 ℃,and failure of the drilling steering device occurs frequently.At high temperatures,the factors affecting the measurement of an MWD device mainly include the device factor(mud pulse and MWD probe) and external factors of the operating environment(vibration,operation,corrosion,etc.).The latter can be improved or mitigated via proper measures.To improve the measurement reliability and trajectory control time-efficiency of the tool,this research investigated the effects of various factors on the device signal quality,such as vibration,thermal tolerance,operation and service environment,and developed specific technical measures.The research and field application shows the measurement reliability of MWD at high temperatures can be improved via proper technical measures by optimizing the mud motor drill dimensions,well trajectory,pulse generator time interval and mud circulation rate.This effectively reduces the device failure rate in ultra-deep directional/horizontal wells and enhances the well trajectory control performance of ultra-deep horizontal wells.The application of the presented technology to wells(e.g.SHB1-4HCH)delivers excellent performance,which validates the practicability of the proposed measures and provides valuable references for operations in analogous areas.