钻柱静态变形的有限元分析

Finite-element analysis for static deformation of drill pipes

描述石油钻柱静态变形的有限元方法.在对钻柱运动进行基本假设的基础上,描述对钻柱进行有限元分析的基本过程,包括考虑几何非线性的势能函数、单元刚度矩阵和外载荷的计算公式、坐标变换等.在有限元方程的求解方面,讨论接触非线性和钻柱大变形问题的迭代处理方法.最后,应用有限元程序的计算结果,分析钻柱在钻头处的侧向力和各种钻井参数的关系.

Static deformation of drill pipes is discussed by using finite element method. Basic finite element technique for analyzing is described, including discretization and interpolation, forming of stiffness matrix and external force vector, solution for contact and nonlinear problem, etc.. As application, side forces at bit are calculated and analyzed for some typical BHA and drilling parameters.