摩阻与扭矩分析在水平井钻井设计中的运用

摩阻与扭矩对水平井钻井施工的影响非常大，决定了起下钻及钻进施工能否正常进行，因此，在钻井设计中提前进行摩阻与扭矩分析，对成功完成钻井作业具有积极作用。文章就摩阻与扭矩对钻具屈曲、当量米塞斯应力、侧向载荷和扭矩等进行了校核，即在滑动钻进时不发生屈曲:当量米塞斯应力校核的安全系数需要在1.67以上、低于屈服极限的60%;侧向载荷必须低于1 000 N/m;扭矩必须低于IADC推荐钻杆最大扭矩的90%。文章通过实例阐述了摩阻扭矩分析在造斜段螺杆钻具组合滑动钻进、复合钻进及水平段旋转导向钻进时的钻具屈曲校核、当量米塞斯应力校核、侧向载荷校核和扭矩校核的具体作法和步骤，以及滑动钻进的极限井深。通过实例井实钻效果分析，认为摩阻扭矩分析是钻井设计阶段水平井钻具组合可行性论证的不可或缺的重要步骤，是安全、优质、高效钻井的基本保证，可以为国内钻井设计部门和定向井技术服务公司在水平井设计中提供参考和借鉴。

Application of Drag and Torque Analysis in the Design of Horizontal Wells

The influence of drag and torque on horizontal well drilling is very great, which determines whether tripping and drilling can be performed normally. Therefore, the drag and torque analysis in advance in the design of a horizontal well plays a positive role in the successful drilling operations. This article introduces main research contents involved in drag and torque analysis. The effects of drag and torque on buckling, Von Mises stress, side force and torque of drilling tool are checked in this paper. That means that no buckling occurs during sliding drilling if the safety factor for Von Mises check is above 1 . 67, that is, less than 60% of the yield limit, the side force must be within the allowable range, that is, less than 1 000 N /m, and the torque must be less than 90% of the maximum torque limit of drill pipe recommended by IADC. The article uses actual cases to illustrate the specific methods and steps for the drilling tool buckling check, Von Mises stress check, side force check and torque check during slide drilling and rotary drilling with PDM in the curve section, and rotary steerable drilling in horizontal section during the drag and torque analysis. Additionally, how to calculate the maximum well depth that the PDM drilling assembly can accomplish slide drilling is also stated. Through the analysis of actual drilling effect of cases, it is considered that the drag and torque analysis is an indispensable tool for the feasibility demonstration of the drilling assembly of horizontal well in the drilling design stage, and is the basic guarantee of safe, high-quality and efficient drilling. It can provide references significance for domestic drilling design departments and directional well technical service companies in horizontal well design.