Method for hierarchically diagnosing fault of rod-comprising oil pumping system based on indicator diagram

Abstract

The invention discloses a method for hierarchically diagnosing a fault of a rod-comprising oil pumping system based on an indicator diagram. The method comprises two stages, namely a fault distinguishing stage and a fault recognizing stage, and comprises the following steps of: dividing the indicator diagram into a fault class and a non-fault class according to a statistical law of the normal sample at the fault distinguishing stage; and recognizing a fault type of a fault sample by a search tree method for recognizing the fault of the rod-comprising oil pumping system based on the indicator diagram. By the method, the fault diagnosis performance of a fault diagnosis system is improved, a mechanical model of the rod-comprising oil pumping system does not need establishing or resolving, the problem of a training set is solved, and the basic features of the rod-comprising oil pumping system can be reflected.

Description

technical field [0001] The invention relates to a fault diagnosis method for a rod pumping system based on a dynamometer diagram, in particular to a fault diagnosis method for a rod pumping system based on a dynamometer graph, and belongs to the technology of a fault diagnosis method for a rod pumping system field. Background technique [0002] The rod pumping system has a bad working environment and a high probability of failure. If it is not diagnosed in time, it will cause waste of energy, affect production, and cause losses to enterprises and the country. [0003] At present, the fault diagnosis of the rod pumping system is mainly based on the dynamometer diagram on the ground, and the pumping diagram obtained through the mechanical model of the rod pumping system, and then the pumping diagrams of normal samples and as many types of fault samples as possible are used as training sets. After the corresponding model is trained, fault diagnosis is performed on each sample....

AI Technical Summary

Problems solved by technology

This type of method mainly has two problems: first, the rod pumping system is a complex nonlinear system coupled with electromechanical and hydraulic systems, and it is difficult to accurately determine the boundary conditions and damping coefficients, and it is difficult to accurately establish and solve the mechanical properties of the system. The second is that the rod pumping system has the characteristics of large sample size, many steady states, and unbalanced categories, so that the training set lacks many types of fault samples, especially the samples of serious faults, and the accurate and real-time diagnosis of serious faults is very important. Rod pumping system is of great significance

In addition, the number of pumping units in the existing oil production industry is large and widely distributed, which increases the complexity of downhole conditions, makes each well have its own characteristics, and the types of possible failures are not fixed

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