水平井钻柱受力变形分析的曲梁单元
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摘要
在水平钻井中，井身曲率较常规定向井井身曲率大。若用直梁单元来分析钻柱的受力变形值，为了确保计算精度，其单元划分势必不能过大，因而单元数必然增多、计算时间增长，影响解题效率和推广应用。根据有限元法的基本原理，研究了适合于水平井钻柱受力变形分析的圆弧曲梁单元及刚度矩阵＊＊，并编制了相应的计算机程序。经典型例题和水平井钻柱力学分析计算结果表明：对于同一结构，在计算精度不变的条件下，曲梁单元少于直梁单元，且计算时间缩短，这对于曲率较大的水平井钻柱进行非线性力学分析尤为重要。因此，对曲率较大的钻柱进行力学分析时，完全可以用曲梁单元取代直梁单元来降低计算时间。
In the light of the basic principle of finite element method,the arc bent beam units and rigidity matrix suited to the deformation analysis of drill stem in horizonat well are researched and the relevant computer procedure is worked out.Typical example and compulation result of mechanics analysis of horizontal well drill stem show:For the same structure and in the condition of constant computation precision,the number and compulation time of bent beam units are less than those of straight beam units,which is very important for nonlinear mechanics analysis of the horizontal drill stem with bigger curvature.So it is feasible replacing straight beam units by bent beam units to reduce computation time when doing the mechanics analysis of drill stem with bigger curvautre.
In the light of the basic principle of finite element method,the arc bent beam units and rigidity matrix suited to the deformation analysis of drill stem in horizonat well are researched and the relevant computer procedure is worked out.Typical example and compulation result of mechanics analysis of horizontal well drill stem show:For the same structure and in the condition of constant computation precision,the number and compulation time of bent beam units are less than those of straight beam units,which is very important for nonlinear mechanics analysis of the horizontal drill stem with bigger curvature.So it is feasible replacing straight beam units by bent beam units to reduce computation time when doing the mechanics analysis of drill stem with bigger curvautre.
引文
1朱伯芳．有限单元法原理与应用．北京：水利电力出版社，19792李国豪等．曲梁桥地震分析的有限元法．同济大学学报，1984（1）3吕和祥等．曲梁单元和它的收敛率．应用数学和力学，1989（6）4张学鸿，刘巨保．水平井钻柱接触问题的间隙元法．计算结构力学及应用，1992（4）
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