螺杆动力钻具压耗计算方法研究与分析

Research and analysis on PDM pressure loss calculation method

随着深井、超深井和大位移井技术的发展,螺杆动力钻具(PDM)的使用越来越普遍,围绕着螺杆动力钻具压耗的计算也越来越受到钻井工作者的重视。通过对已有螺杆钻具压耗计算方法的归纳和总结,将螺杆钻具压耗计算方法分为一般法与模型法两大类,并对其进行了详细的分析比较。同时,优选罗伯逊—斯蒂夫钻井液流变模式,详细推导了圆筒模型中螺杆钻具压耗的计算方法。最后,完善了模型法中复杂模型法的螺杆钻具压耗推导过程。结果表明,当对螺杆钻具压耗计算精确度要求较高时,可选用模型法里的复杂模型方法来计算。

With the development of the deep well, ultra deep well and extended reach drilling （ERD） technologies, the Positive Displacement Motor （PDM） has been used more and more popularly. Meanwhile, the pressure loss calculation method is paid much more attention. By concluding and summarizing the present pressure loss calculation methods, the paper divided them into two categories, general methods and model methods, for comparison and analysis in detail. In addition, the Roberston-Stiff（R-S） rheological model has been selected to deduce the pressure loss calculation method in the cylindrical model. Finally, the derivation process of the complex model, one of the model methods, has been perfected. The result shows that we can choose the complex model calculation method to get a high accuracy of pressure loss.