中短半径水平井弯壳螺杆钻具造斜率预测方法研究

Study on prediction methods of build-up rate of PDM with bent housing for middle-short radius horizontal well

准确的造斜率预测是侧钻中短半径水平井成功的关键。根据中短半径水平井的特点 ,提出了用极限曲率法和修正的三点定圆法来预测弯壳螺杆钻具的造斜能力 ,并对典型螺杆钻具的造斜率进行了预测和敏感性分析 ,以指导螺杆钻具的设计、选择和井眼轨迹控制。文中所述两种预测方法可较好地预测工具的造斜率 ,能满足中短半径水平井的需要 ,并得到了现场验证。

Exactly predicting the build-up rate is the key to success in middle-short radius horizontal well.The limiting curvature method and the modified three point geometry method are presented to predict the build-up capability of positive displacement motor (PDM) with bent housing on the basis of distinguishing feature of middle-short radius horizontal well.Then the prediction and sensitivity study of build-up rate are made for representative PDM so as to guide the design and selection of PDM and well trajectory control.Both methods in this paper can predict the build-up rate of tools better and meet the requirement of middle-short radius horizontal well,which is verified in the field.