Abstract: Three-dimensional analysis of the static behavior of a bottomhole assembly(BHA)under large deflection has been carried out successfully with the method of weighted residuals(MWR).The BHA analysis program thus developed has the advantages of universal application,higher accuracy,simplicity and time saving,and is suitable for the computation for a variety of BHAs under large deflection.The results obtained by the typical computation show that some large deflection effects on BHA behavior increase with increased borehole-curvature、and an analysis program for BHA under small deflection should not be used in medium or large-curvature drilling.

摘要： 应用加权余量法(简称权余法)对下部钻具组合(BHA)大挠度问题进行求解的基础上编制了简单通用的BHA大挠度分析程序,它具有通用性强、计算精度高及简单省时等优点,可以在微机上运行,能模拟计算各种转盘钻下部钻具组合的大挠度力学特性.通过典型计算,本文阐明了井眼曲率对BHA大挠度非线性效应的重要影响,并且给出了BHA小挠度分析程序的大体适用范围.

关键词: 钻具组合, 弹性曲杆, 定向井, 水平井, 加权余量法