电机变速运行对抽油系统影响规律研究

发布时间：2019-06-29 18:29

【摘要】：电动机在工频下运转时,曲柄轴扭矩波动幅度较大,严重影响了抽油机系统平衡,即增加能耗,又降低设备寿命。电机变频技术目前在油田应用较为广泛,但是多以现场测试数据和经验来研究变频效果,缺乏理论依据。本文从理论出发,基于国内外有杆抽油系统仿真成果,精确分析了曲柄在匀速和变速情况下四连杆机构以及悬点的运动规律;分析推导了非变频与变频条件下曲柄运动规律方程以及考虑抽油杆柱纵向振动的一维波动方程;建立了基于以上两个耦合方程的有杆抽油系统数学仿真模型,运用迭代法求解;对比实测数据与仿真数据,有较高的精度,并且在采用变频措施后抽油机的运行工况有明显的改善。采用多因素模糊综合评判方法,确立了基于悬点载荷、曲柄扭矩、抽油杆柱应力和系统效率等的评价指标体系,以及隶属函数及约束条件,以模糊评判结果值最大为目标,用鲍威尔算法优选出最优的变频方案。通过对比变频前后仿真结果发现,悬点载荷、曲柄扭矩、电机功率峰值均有较大幅度的降低,最大载荷降幅达到10.5%,应力范围比也有很大的改善,对于两级抽油杆,其两级杆的应力范围比更加接近;对现场应用该技术后的效果做了统计分析,结果表明,采用变频技术后,抽油系统多项指标均有较大的改善,对理论提供了进一步的验证。基于理论研究与现场实际,开发了一套基于C#程序语言和Matlab语言的抽油机系统变频动态控制软件。
[Abstract]:When the motor runs at power frequency, the torque of crank shaft fluctuates greatly, which seriously affects the balance of pumping unit system, that is, increasing energy consumption and reducing equipment life. At present, motor frequency conversion technology is widely used in oil fields, but most of them are based on field test data and experience to study the effect of frequency conversion, which is lack of theoretical basis. In this paper, based on the simulation results of rod pumping system at home and abroad, the motion law of four-bar mechanism and suspension point under the condition of uniform speed and variable speed is accurately analyzed, the law equation of crank motion under the condition of non-frequency conversion and the one-dimensional wave equation considering the longitudinal vibration of sucker rod string are analyzed and deduced, and the mathematical simulation model of rod pumping system based on the above two coupling equations is established and solved by iterative method. Compared with the measured data and the simulation data, the accuracy is higher, and the operating conditions of the pumping unit are obviously improved after the frequency conversion measures are adopted. By using the multi-factor fuzzy comprehensive evaluation method, the evaluation index system based on suspension point load, crank torque, sucker rod column stress and system efficiency, membership function and constraint conditions are established. Aiming at the maximum fuzzy evaluation result, the optimal frequency conversion scheme is selected by Powell algorithm. By comparing the simulation results before and after frequency conversion, it is found that the suspension point load, crank torque and motor power peak value are greatly reduced, the maximum load drop is 10.5%, and the stress range ratio is also greatly improved. for the two-stage sucker rod, the stress range ratio of the two-stage sucker rod is closer to that of the two-stage sucker rod. The effect of the field application of this technology is statistically analyzed. The results show that many indexes of the pumping system are greatly improved after the frequency conversion technology is adopted, which provides a further verification of the theory. Based on theoretical research and field practice, a set of frequency conversion dynamic control software for pumping unit system based on C # program language and Matlab language is developed.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE933.1

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