基于电功图的抽油机井工况诊断模型

针对目前缺乏典型工况特征的电功图图集而导致电功图资料无法被充分应用、采油生产系统实时工况诊断难等问题,考虑曲柄实际角速度、四连杆的惯性、摩擦等因素,推导基于光杆示功图的电功图计算模型,建立13种油井工况下的典型电功图特征图集和基于特征值的电功图工况诊断模型,并编制工况诊断软件。经现场5口油井功图计算检验,结果表明:实测电功图与计算电功图的上、下冲程功率峰值、功率的极差、平均功率的平均相对误差分别为1.74%、3.89%、2.96%、1.74%。经现场6口油井电功图的工况诊断检验,该井下工况诊断结果与示功图诊断结果一致,表明基于电功图的抽油机井工况诊断模型准确率高,能为抽油机井采油系统智能分析和优化决策提供技术支持。

A diagnosis model on working condition of pumping unit in oil wells based on electrical diagrams

The real-time diagnosis on the working conditions of oil production well system can be carried out based on the electrical diagram data of oil pumps, in which the characteristics of the electrical diagram at typical working conditions should be understood. In this paper, a mathematical model transforming the mechanical work diagram of the pump rod to electrical diagrams was derived in consideration of various factors, including the actual angular velocity of the crank, the inertia and friction of the four bar linkage. A diagnostic model and software was compiled, in which 13 typical electrical diagrams corresponding to different working conditions were considered. The results for case studies of 5 wells show that the average relative errors of the peak power in up and down strokes, the range of power and the average power between measured electrical diagrams and those calculated are 1.74%,3.89%,2.96%,1.74% respectively. The diagnosis results on the working conditions of 6 wells in an oilfield have shown the effectiveness and accuracy of the new method.