Research On Multiple Faults Diagnosis Of Sucker Rod Pumping System Based On Designed Component Analysis

In the process of exploitation in oil well, oil production equipments almost work in the fields which are located in scattered geographic position. Normally, they are several thousand meters deep under the ground and so have complicated working condition. The failures frequently happened in the pump result in low efficiency of oil production. In order to ensure the normal and efficient production of oil, the traditional method is that oil expert analysis the indicator diagram collecting from field and judge the condition of pump, then pump with fault can be detected and repaired. However, one disadvantage of this kind of method is that it needs a large number of experts to do the boring work, and may lead to misjudgment due to the different standards. With the aim to save this manpower and realize the automatic monitoring and judgment of oil production, the methods of fault detection and analyzing are introduced which are based on computer techniques. The traditional fault diagnosis methods are evolved in the basis of indicator diagram. And there is one supposition within it. It assumes that only one fault occurs in every indicator diagram with failure. Even though one fault happens more frequent than multiple faults at one time, the situation which several faults exist at the same time are also very common. The method diagnosing single fault is not applicable in the multiple faults situation in oil pump. From the literature related to multiple faults diagnosis of oil pump, there is not very effective method which can be used to diagnose multiple faults at present. Inspired by the thought of primary component analysis and expert system, designed component analysis is proposed toward the multiple faults in oil pump. From the result of theoretical analysis and simulation, the algorithm is proved to be effective with the problem. Though it cannot lead to a perfect resolution, the method has laid a solid foundation for in-depth study.The main work of this paper can be concluded as following:Firstly, this thesis introduces the industrial background and basic principles of rod pump sucker. Then the fault diagnosis problem is raised during oil pumping. And it is be summarized by us that how theories of fault diagnosis develop and are applied to actual practice. The problem that will be solved is also pointed out at the beginning.Secondly, by building dynamic equation of sucker rod based on Gibbs equation, then solving the equations through mathematical methods, transforming the ground indicator diagram into underground one which eliminate the effect of inertia load, vibration load, depth and production parameters of wells. Therefore working condition of oil pump can be diagnosis more accurate.Finally, paper summarizes some method of feature extraction, and extracts single fault parameter based on expert experience. Then the fundamental ideas of PCA are simply introduced. According to the needs and difficulties of multiple faults diagnosis of oil pump, the designed component analysis method is proposed to solve it. Each designed component is analyzed statistically based on large amount of history data collecting from the field. The simulation result proves that multiple faults can be detected effectively by the proposed method.