抽油杆柱动态特性的计算机模拟

在分析有杆抽油系统抽油杆柱井下基本工况、运动和动力特性的基础上 ,根据抽油机光杆运动方程 ,确定了抽油杆柱井下运动的 4个时间区段及边界条件。采用有限元软件MARC按不同时间区段对多级抽油杆柱的运动和动力学特性进行计算机模拟 ,得到计算机模拟的地面示功图和抽油杆柱一个上下冲程循环中各节点的位移与载荷随时间变化的动态特性曲线。分析对比计算机模拟曲线和实测曲线表明 ,采用有限元软件MARC获得的抽油杆柱计算机动态模拟结果与测试结果基本吻合 ,前者可作为后者的度量基准 ,动态模拟曲线还可为游梁式抽油机设计和井下故障诊断提供理论依据

Computer simulation for the transient dynamic characteristics of sucker rod string

In light of the kinetic characteristic of the polished rod and actual working condition of the sucker rod string in a hole, a finite element model of a multi stage sucker rod string is made. Its transient kinematics and dynamic characteristics are simulated in an environment of the finite element software MARC at different time periods. The kinematic parameter and stress vs time characteristic curves are described accurately. The kinetic characteristic at the ends of the rod string will provide foundation for designing subsurface pumps and determining reasonable pump stroke. The stress behavior at every part of the rod string will provide a basis for designing pumping units and determining the working load.