Working-condition diagnosis of a beam pumping unit based on a deep-learning convolutional neural network

At present, beam pumping units are the most extensively-applied component in rod pumping systems, and the analysis of the indicator diagram of a rod pump is an important means of judging its downhole working condition. However, the synthetic study and judgment of the indicator diagram by manual means has a low efficiency, large error, and poor immediacy, and it is difficult to apply the conclusions in time and accurately to adjust the operating parameters of the pumping units. Moreover, expert systems rely on expert experience and conventional machine learning requires manual pre-selection of geometric features such as moments and vector curves, which will reduce the accuracy of recognition when similar indicator diagrams appear. To solve the above technical defects, in this paper, a deep-learning convolutional neural network (CNN) is proposed using the CNN model based on AlexNet. The automatic recognition of the indicator diagram is thus realized, and, on the basis of previous studies, this model simplifies the structure of the model and takes into account 15 common downhole working conditions of the pumping unit. In this model, the batch normalization (BN) layer is used to replace the local response normalization (LRN) and dropout layers and all kinds of indicator diagrams are put into the same model frame for automatic identification. The experimental application of the measured data shows that the model not only has a short training time, but also has a working-condition diagnosis accuracy of 96.05%, which can solve the deficiencies and defects of artificial identification, expert systems, and conventional machine learning to a certain extent. A deep-learning CNN can provide a new reference for fast working-condition diagnosis of indicator diagram, making indicator-diagram judgment timely and accurate, and thus it is possible to provide a direct basis for parameter adjustment of pumping units.