电机直驱游梁抽油机抽油系统动力学分析与平衡参数优化

【作者】 陈波；

【导师】 李琴； 刘昆明；

【作者基本信息】 西南石油大学 ， 工程硕士（专业学位）， 2019， 硕士

【摘要】 游梁式抽油机是发明最早、应用最广泛的抽油机,其具有结构简单、工作状态稳定的特点,广泛应用于新疆克拉玛依油田采油作业中。然而,克拉玛依油田位于沙漠、戈壁中,常年干旱少雨,夏天室外温度极高,且温差大,而冬天温度极低,常年风沙较大。在这种恶劣的工作环境下,常规游梁式抽油机的皮带、皮带轮、减速箱装置极易损坏,造成油井停工停产,严重影响了油田的正常开采,成为了克拉玛依油田亟待解决的问题。为了解决这一问题,本文在CYJY4-1.5-13HB的基础上,设计了一种电机直驱游梁式抽油机,并进行了以下几方面的研究与分析:(1)以4型电机直驱游梁式抽油机为研究对象,推导了抽油机运动学理论公式,建立了抽油机力学方程,分析了悬点位移、速度、加速度的变化规律,校验了游梁摆角和连杆转角幅度。结果表明改造后的电机直驱游梁式抽油机运动参数满足抽油机设计要求。(2)将油管中流体视为库埃特流,推导了油液沿油管的沿程能量耗散函数,计算了抽油杆上下冲程的沿程粘性能耗;考虑抽油杆接箍和扶正器的影响,推导了油液流经接箍和扶正器时的局部能量耗散函数;基于等摩擦功原理,推导了抽油杆系统等效阻尼系数理论公式,分析了抽油杆系统等效阻尼系数的影响规律;结果表明:①在强度足够的情况下选用尺寸较小的抽油杆,有助于减小局部粘性能耗。②减小抽油杆接箍和扶正器处截面积的突变,对于降低阻尼力有显著效果。(3)考虑抽油杆接箍和螺纹的影响,推导了抽油杆杆体变形、接箍变形、螺纹轴向拉伸变形理论公式;借助于等效变形法,推导了抽油杆等效拉伸刚度理论公式;进行了抽油杆等效拉伸刚度敏感性分析;结果表明:①等效拉伸刚度对于抽油杆自重、抽油杆杆体长度、接箍长度的敏感度较小,而等效拉伸刚度对于螺纹连接在抽油杆轴向的投影面积的敏感度较大。②在计算抽油杆等效拉伸刚度时,螺纹连接的影响是不可忽略的,在计算时应该考虑螺纹的影响。(4)考虑抽油杆纵向振动,建立了抽油杆多自由度质量-弹簧-阻尼系统物理模型;在广义坐标系下,推导了系统动能、势能、广义力表达式;建立了抽油杆柱动力学模型。以克拉玛依油田#5110井的井况参数为依据,求解动力学微分方程组得到了该井的计算示功图。结果表明:计算示功图和实测示功图曲线非常接近,一个周期的85%以上,示功图计算误差都在5%以内;动力学模型适用于悬点载荷的预测。(5)建立了 4型电机直驱游梁式抽油机动力学仿真模型,借助于Adams动力学仿真软件,分析了曲柄平衡重对曲柄扭矩的影响规律、尾梁平衡重对曲柄扭矩的影响规律、复合平衡对曲柄扭矩的影响规律;以曲柄扭矩为目标参数,进行了抽油机平衡参数的优化设计;最后,仿真分析了最佳平衡参数下抽油机运动学参数。结果表明平衡重对于曲柄扭矩有较大影响,曲柄扭矩最大值与平衡重的关系曲线呈“V”形,随着平衡重增加,曲柄扭矩最大值先是呈线性递减,随后呈线性递增;整体来说,复合平衡效果优于曲柄平衡和尾梁平衡。平衡结构优化后,最大曲柄扭矩明显减小,降低了直驱电机的最大输出扭矩,有效控制了直驱电机的制造成本。综上所述,本文通过抽油机的运动学与力学理论分析,校验了电机直驱游梁式抽油机的性能参数,并为抽油机的动力学仿真垫定了理论基础;在研究抽油杆等效阻尼系数与等效拉伸刚度的基础上,进行了抽油杆杆柱动力学分析,得到了悬点的计算示功图,并以悬点计算示功图参数为抽油机悬点载荷,对抽油机平衡结构进行了优化设计,减小了抽油机的最大曲柄扭矩,从而降低了直驱电机的制造成本。该研究对于克拉玛依油田游梁式抽油机改造、提高抽油机安全可靠性、实现油田的降本增效具有重大意义。更多还原

【Abstract】 The beam pumping unit is the earliest and most widely used pumping unit.It has the characteristics of simple structure and stable working condition,and is widely used in the oil production operation of the Karamay oilfield in Xinjiang.However,the Karamay oilfield is located in the desert and Gobi.It is dry and rainless all year round.The outdoor temperature is extremely high in summer and the temperature difference is large,while the winter temperature is extremely low and the wind and sand are large all year round.In this harsh working environment,the belt,gearbox and pulley device of the conventional beam pumping unit are easily damaged,resulting in the shutdown of the oil well and severely affecting the normal exploitation of the oil field,which has become an urgent problem to be solved in the Karamay oilfield.In order to solve this problem,based on CYJY4-1.5-13HB,a direct-drive beam pumping unit for motor drive is designed and related research and analysis are carried out,and the following research and analysis are carried out:(1)Taking the 4-type motor direct-drive beam pumping unit as the research object,the theoretical formula of kinematics of pumping unit is deduced,the dynamic equation of pumping unit is established,and the variation law of displacement,velocity and acceleration of suspension point is analyzed,the beam swing angle and the link angle range are verified.The results show that the modified motor direct drive beam pumping unit’s motion parameters meet the performance requirements.(2)The fluid in the pumping pipe is regarded as the Couette flow,and the energy dissipation function of the oil along the path is derived.The viscous energy consumption along the up and down stroke of the sucker rod is calculated.Considering the influence of the sucker rod coupling and the centralizer,the local energy consumption function of the oil flowing through the coupling and the centralizer is derived.Based on the principle of equal friction work,the theoretical formula of equivalent damping coefficient of sucker rod system is derived,and the influence law of equivalent damping coefficient of sucker rod system is analyzed.The results show that:①When the strength is sufficient,the smaller size of the sucker rod is used to help reduce the local viscous energy consumption.②Reducing the sudden change in the cross-sectional area of the sucker rod coupling and the centralizer has a significant effect on reducing the damping force.(3)Considering the influence of the sucker rod coupling and the thread,the theoretical formula of the rod body deformation,the coupling deformation and the axial tensile deformation of the sucker rod are derived.Based on the equivalent deformation method,the theoretical formula of the equivalent tensile stiffness of the sucker rod is derived.The sensitivity analysis of the equivalent tensile stiffness of the sucker rod is carried out.The results show that:①The equivalent tensile stiffness is less sensitive to the weight of the sucker rod,the length of the rod of the sucker rod,and the length of the coupling,and the equivalent tensile stiffness is more sensitive to the projected area of the threaded rod in the axial direction of the sucker rod.②When calculating the equivalent tensile stiffness of the sucker rod,the influence of the threaded connection is not negligible,and the influence of the thread should be considered in the calculation.(4)Considering the longitudinal vibration of the sucker rod,the physical model of the multi-degree of freedom of the sucker rod-spring-damping system is established.In the generalized coordinate system,the kinetic energy,potential energy and generalized force expression of the system are derived.The dynamic model of the sucker rod column is established.Based on the well condition parameters of Well#5110 in Karamay Oilfield,the computational work diagram of the well is obtained by solving the dynamic differential equations.The results show that:the calculation of the dynamometer and the measured dynamometer are very close.The calculation error of the dynamometer is less than 5%in more than 85%of the cycle;the dynamic model can predict the fulcrum.(5)With the aid of Adams dynamics simulation software,the dynamic simulation model of the 4-type motor direct-drive beam pumping unit was established.The influence law of crank balance weight on crank torque,the influence of tail beam balance weight on crank torque and the effect of compound balance on crank torque are analyzed.With the crank torque as the target parameter,the optimal design of the pumping unit balance parameters is carried out.Finally,the pumping machine movement and the force state of the components under the optimal balance parameters are simulated and analyzed.The results show that:the balance weight has a greater influence on the crank torque.The curve between the maximum crank torque and the balance weight is "V" shape.With the increase of balance weight,the maximum crank torque first decreases linearly,then increases linearly.Overall,the composite balance effect is better than the crank balance and tail beam balance.After the balance structure is optimized,the maximum crank torque is significantly reduced,which reduces the maximum output torque of the direct-drive motor and effectively controls the manufacturing cost of the direct drive motor.In summary,this paper analyzes the performance parameters of the direct-drive beam pumping unit through the kinematics and dynamics theory analysis of the pumping unit,and lays a theoretical foundation for the dynamic simulation of the pumping unit.Based on the study of the equivalent damping coefficient and the equivalent tensile stiffness of the sucker rod,the dynamic analysis of the sucker rod is carried out,and the calculation diagram of the suspended point is obtained.The parameters of the power diagram are calculated as the suspension point load of the pumping unit,the balance structure of the pumping unit is optimized,the maximum crank torque of the pumping unit is reduced,and the manufacturing cost of the direct drive motor is reduced.This research is of great significance for the transformation of the beam pumping unit in the Karamay oilfield,improving the safety and reliability of the pumping unit and increasing the oil recovery efficiency of the oilfield.更多还原