地面驱动螺杆泵采油系统抽油杆等效节点载荷分析

为了解抽油杆在井下的受力和运动状态,使其脱断事故得到合理的解释,运用抽油杆单元有限元模型分析了地面驱动螺杆泵采油系统抽油杆在井筒中的受力和运动状态。在对问题进行求解之前,需要得出整体等效节点载荷向量,考虑到井斜,利用抽油杆单元各方向上的位移插值函数,根据虚功原理将均布载荷转化成为节点的等效载荷,然后按节点顺序装配出整体等效节点载荷向量。求解由整体刚度矩阵和整体等效节点载荷向量形成的线性方程组,可得出某一时刻抽油杆各节点不同方向的位移。对抽油杆扶正器位置安装具有指导意义。

Analysis of Equivalent Nodal Load in Ground Drive Progressive Cavity Pump System of Oil Production

Understanding the state of stress and movement of the sucker rods is needed, in order to explain the rod accident. Firstly this research quotes the Finite Element model to analyse the sucker rod＇s state of stress and motion in the ground driving progressive cavity pump system of oil production. Before solving the problem, the vector containing the equivalent nodal loads should be calculated out. Taking the angle of inclination into account, the equivalent loads of each node can be got by the help of displacement interpolation function of each direction in element rod ac- cording to the principle of virtual work. The vector containing the equivalent loads of each node would be assembled into system vector according to the sequence of the nodes. The total displace- ment vector can be obtained by solving the Linear equations composed of total Stiffness matrix and Equivalent nodal force vector,which couldguide the installation of centralizers.