传统底部钻具组合上切点边界条件的正确性

ACCURACY OF THE BOUNDARY CONDITIONS AT THE UPPER TANGENT OF THE CONVENTIONAL BHA

传统的底部钻具组合受力分析的上切点处的边界条件表达为 :1.与下井壁接触 ;2 .转角与井眼轴线的一致 ;3.曲率与井眼轴线的一致。该表达方法已经采用了多年 ,应用效果良好。近来 ,有文章否定该边界条件 ,文中例证了传统底部钻具组合上切点边界条件的正确性。

The boundary conditions at the upper tangent of the conventional bottom hole assembly can be expressed as: 1. Contacts the lower side of the bore wall; 2. The corner angle conforms to the hole axial line; 3. The curvature conforms to the hole axial line. This expression has been used for years with no problem, yet some paper at home denies it lately. The accuracy of the boundary conditions expression is illustrated and proved in this paper.