Failure Model and Intelligent Diagnosis Method of ProcessControl of EPCP

The failure diagnosis indicators are featured by nonlinear separable similarity and uncertain relationship between failures and indications.It is difficult to conduct effective failure diagnosis on site for the electric submersible screw pump(EPCP)unit.Based on the statistical process control extended criterion and empirical judgment,multi-parameter rule charts,failure weight factor and normalization of collected field data,a failure diagnosis model of ESPCP unit was established,and a failure diagnosis method of multi-parameter process control was proposed.The operation and failure types of electric submersible screw pump unit are divided into 12 working conditions,7 characteristic parameters such as electrical parameters and production parameters were selected to characterize the production conditions of oil wells,and the judgment criteria and weight factors of on-site failure conditions were determined.Combined with the judgment trend of process control extended criteria and data feedback analysis,the failure with the highest probability is output.According to the on-site measured parameters of more than 20 failure wells in Xinjiang Oilfield,example calculation and verification analysis were carried out.The results show that the failure diagnosis method of multi-parameter process control and data feedback has strong analysis function and visualization.It provides theoretical basis and technical support for timely diagnosis and accurate judgment of the operation conditions and failures of ESPCP units.