基于示功图的抽油机平衡诊断与调整

摘要

Considering the effect of unbalance of pumping unit on the safety and efficiency of well production systems,the mathematical relationships between the polished rod load and the motor output power of the 4 pumping units are derived.According to the given indicator diagrams,the output power of the motor-the polished rod displacement is attained.Real-time intelligent diagnosis and adjustment of the balance of the pumping unit is established.The case study calculation results show that the calculated power-displacement diagram based on the indicator diagram is close to the measured power-displacement diagram.The average relative errors between the calculated and measured upper stroke power peak,lower stroke power peak,power range,and average power are 3.69％,5.03％,1.26％ and 2.63％.The calculated and measured balance values of the Well X1 are 0.26 and 0.25,respectively.The pumping unit is in underbalanced condition.The calculated and measured balance values of the Well X2 are 1.34 and 1.29,respectively.The pumping unit is in an overbalanced state,which indicates that the balance diagnosis has a high accuracy.The research results show a broadened application scope of the indicator diagram,which provide theoretical and technical supports for real-time intelligent balance diagnosis and adjustment of rod-pumped wells,and help improve the production efficiency and benefits of oil wells.%针对抽油机不平衡影响抽油机设备安全及油井生产系统效率等问题,推导了4种类型抽油机井悬点载荷与电机输出功率的数学关系模型,根据已知示功图计算电机输出功率-悬点位移图,并进行抽油机平衡的实时智能诊断与调整.计算结果表明:基于示功图计算的功率-位移图与实测功率-位移图很接近,计算与实测的上冲程功率峰值、下冲程功率峰值、功率极差和平均功率的平均相对误差分别为3.69％、5.03％、1.26％和2.63％;X1井平衡度的计算值和实测值分别为0.26和0.25,抽油机处于欠平衡状态;X2井平衡度的计算值和实测值分别为1.34和1.29,抽油机处于过平衡状态,这表明平衡诊断具有较高的精度.研究成果拓宽了示功图的应用范围,可为抽油机井实时智能平衡诊断与调整提供理论与技术支持,有利于提高油井生产效率与效益.