Research On Lean Maintenance Technology Of Sucker-rod Pumping System

Rod pumping system is most widely used in oil production, and its safely, reliably and efficiently running is a long-term task to oil industry for the purpose of high benifit-cost ratio. Many researches on condition monitoring and fault diagnosis of rod pumping system have been carried out, yet it is not enough to reach the target. From system perspective, the working of rod pumping system depends on complex interactions between rod pumping unit, oil pump, oil well, working environment and operation workers. In this sense, it is necessary to introduce some newly developed maintenance theories, which will be systematic and practical to the maintenance of rod pumping system, with the aid of fault analysis and fault diagnosis technology. This may lead to optimal fault control strategy, changing from breakdown maintenance to preventive maintenance, and reach the target of low maintenance cost and high production efficiency.The research focouses on the maintenance and management of the sucker-rod oil pumping system. For this purpose, a new concept "Lean Maintenance" proposed in recent years is introduced; a Lean Maintenance frame is put forward and applied to rod pumping system; some theories and technologies such as fault analysis, fault diaonosis and fault control strategy and their applications are studied; the Lean Maintenance Management Information System for rod pumping system is developed. The main works of the research are as follows.Firstly, a new Lean Maintenance technology frame is put forward. In this frame, all the maintenane technologies are classified into three layers, which is the equipment maintenance decision-making technology, site management theory and computer information technology, and it is an extended subset of the existing frame, and can be appied to the maintenance of most equipment.Secondly, the sucker-rod oil pumping system's Lean Maintenance technology frame is constructed, which is a all-around solution for maintenance of sucker-rod oil pumping system, with condition monitoring technology, fault diagnostic technology and fault control strategy technology as its base.Thirdly, three types of fault feature extraction technology as Fourier Descriptor method, area change trend analysis method and wave equation method are studied and applied to indicator diagram analysis, and there are large amount of experimental data acquired.Fourthly, an integrated fault diagnostic model is designed, which combines quantitative diagnosis of indicator diagram based on artificial NN and qualitative diagnosis based on Trend Analysis. The diagnostic results can also be validated mutually with production dynamic control map. The model helps to improve the diagnostic veracity.Fifthly, some fault control strategies are proposed on the study of value stream analysis technology and fault root cause analysis technology, and this will reduce fault's happening repeatly and lower the maintenance cost.Besides the above works, a Lean Maintenance information system for rod pumping is developed. All the research works will not only enrich oil well's production maintenance management theory, but also provide technological tools for oil well's safe production and economic, efficient running.