During drilling a long horizontal-section well,an extended reach well and multilateral wells,rotary steering system can improve drilling speed,reduce downhole accidents and decrease drilling cost greatly because it can prevent sticking and slipping,and have a good result to carry cuttings. The paper has presented the whole project of developed rotary steering motor(RSM) ,the structure and working principle of RSM control system were also be studied in detail. Rotary steering tool is driven by both downhole motor and rotary table. Well trajectory can be effectively controlled by adjusting steering pad. Steering or non-steering status and each pad are controlled by using independent electromagnetic valves,which guarantees reliability and control accuracy of RSM,also simplifies the control method. Downhole motor provides power for bit by driving inner mandril, and provides power for hydraulic system at the same time. The indoor tests show that control method of this system is simple and reliable, and easily carried out,it has laid a foundation for practical application in the future.%旋转导向钻井系统在长水平段水平井、大位移井、分支井等复杂结构井的钻井过程中,可以消除粘滑卡钻,携岩效果好,具有显著提高机械钻速、减少井下故障、降低钻井成本的优势.中国石化胜利油田钻井工艺研究院与美国AGP公司合作开发了旋转导向井下工具系统,该系统由井下专用螺杆和地面转盘双动力驱动,通过控制导向翼肋的定向支出来控制井眼轨迹.其导向和非导向状态及每个导向翼肋的支出均采用独立电磁阀控制,既保证了系统的可靠性,又保证了控制精度,并且简化了控制方法.井下专用螺杆驱动内部心轴不仅给钻头提供动力,还给液压系统提供动力.室内测试证明,该系统控制方法简单可靠,可实现性强,为以后的实际应用推广提供了依据.介绍了旋转导向井下工具系统的整体设计方案,对其控制系统及各部分的结构、工作原理进行了详细研究.
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