Study On Diagnosis Technology Of Marine Esp Well Operating Conditions Based On Underground Information Monitoring

Submersible electric pump is an important mechanical oil production method,which is widely used in offshore oil and gas fields.It is an important problem to be solved in the process of production and management of offshore electric pump wells that how to diagnose operating condition characteristics of downhole units.However,the traditional current card analysis method and the diagnosis method of wellbore pressure holding curve are mainly used in the diagnosis technology of ESP at present.These methods have limitations and one-sidedness due to single diagnostic parameter.The downhole monitoring information parameters are not fully utilized.It's a waste of data.The production system of offshore electric pump well is analyzed based on the theory of oil production engineering and three diagnostic models of ESP operating conditions are established by using the information parameters monitored downhole.Firstly,the diagnostic model of macro-control chart of submersible electric pump is established through the production parameters such as displacement and lift monitored downhole.The macro-control chart is drawn with five condition areas.The characteristics of operating conditions are analyzed and the production conditions of 10 offshore electric pump wells are macroscopically diagnosed.Secondly,a current card diagnosis and analysis model is established based on the current data of underground monitoring.100 sets of current data are standardized and the characteristic parameters of current curve are analyzed.A sample library containing 10 sets of typical characteristic current cards is established.A current card diagnosis and analysis software module is compiled.The module is validated by eight sets of current cards under actual operating conditions.Thirdly,the erosion degree of the outer surface of electric submersible pump is diagnosed based on the flow parameters of ESP wells.A three-dimensional model of the outer surface annulus fluid field of electric submersible motor is established.The flow characteristics of the outer surface of electric submersible pump are numerically simulated by Fluent software and the erosion diagnosis model is established to diagnose the erosion of the outer surface of electric submersible motor in electric pump wells.A diagnostic software for offshore ESP is developed in this paper based on the systematic analysis of ESP and three diagnostic models of ESP conditions.The software includes four functional modules,which can comprehensively analyse the downhole operating conditions of ESP wells and prolong the period of pump inspection.