Extraction of some feature values based on the surface dynamometer card

Geometric feature values are obtained from surface dynamometer card as object of fault distinguish. Method of selecting top dead center and bottom dead center as feature values used in fault distinguish and gaining turn-on and turn-off position of travel and set valve as feature values if necessary in fault identification is proposed. The extraction of valve opening and closing points is the basis for the identification and quantitative analysis of pumping well dynamometer cards, and it is important for the failure diagnosis and production evaluation of pumping wells. This method ensures the independence and compatibility of feature values. And the method reduces the workload and improves identification of feature values as well.