【作者】 张强；

【导师】 刘巨保； 罗敏；

【作者基本信息】 大庆石油学院 ， 工程力学， 2008， 硕士

【摘要】 小型柔式抽油系统主要由小型柔式抽油机和钢丝绳柔性抽油杆组成,考虑曲柄和牵引带作用在抽油机结构上的瞬态载荷,利用多点约束技术,建立了由梁、板壳、实体组成的混合单元有限元模型,采用Newmark积分法,进行小型抽油机的瞬态动力学计算,结果表明:在悬点载荷为3kN~20kN作用下,抽油机各部件均满足强度条件,井口立杆的支撑方式前后安装优于左右安装。建立了柔索与弹性杆非线性瞬态动力学模型,该模型将钢丝绳处理成仅受拉力的LINK10单元,柱塞运动与阻力关系用COMBIN40组合单元加载。经现场5口井的动力学计算表明,悬点载荷的理论值与测试结果基本吻合,悬点静载荷相对误差均小于5%,悬点的最大和最小载荷的相对误差均小于10%;通过各种参数下钢丝绳抽油杆动力学计算表明,钢丝绳弹性模量控制在80GPa以上、冲程冲次选择为2m~3m和1min-1~3min-1、加重杆选择38m~47m(重量335kg~415kg),这些参数为小型柔式抽油系统设计和应用提供了重要依据。利用ANSYS流固耦合功能,研究了偏心抽油杆在层流和湍流状态下的阻尼系数,在抽油杆与油管同心、采出液作层流时,求得的阻尼系数与理论解相对误差为0.60%,证实了所建模型和求解方法的正确性,为偏心抽油杆阻尼系数计算提供了依据。更多还原

【Abstract】 The small flexible pumping system is mainly composed of the small pumping units and flexible rod string. Using multipoint constraints and assemblies technique, beam-shell-solid assembly model is established, and the transient loads is considered. Using newmark method, transient dynamic problem of the small pumping units is researched. The result shows that in the load of 3kN~20kN, every components meets the strength condition, the left-right support is better than the front-back support. The nonlinear transient dynamic model of the flexible rod string and elastic link is established, the model consider the flexible rod string as tension-only spar LINK10 and pump as COMBIN40.The calculation of five wells shows that the theoretical load is basically consistent with test load, the static load relative error is less than 5%, the relative error of maximum and minimum load is less than 10%. Influencing factors of pump stroke shows that the young’s modulus of flexible rod string should be more than 80GPa, the stroke of suspension point should be 2m~3m and the velocity be 1min-1~3min-1, the length of weight rod be 38m~47m, the results can meet the transient dynamic forecasting and design requirements. By fluid-solid coupling analysis method, the damping factor of the different eccentric rod string in the laminar and the turbulent is calculated. The results shows that the numerical result of the laminar damping factor is in accord with the theoretical result and relative error is 0.60%, which provide a theory basis to calculating the damping force of the eccentric rod string.更多还原