Multi-objective Optimization Of Production Parameters And Energy Saving Control Of Low Permeability Oil Wells

At present,our country has abundant proven reserves of low permeability oil and gas resources,which have great potential for subsequent development,but the development of low permeability oil fields is constrained by the low permeability of the formation,which leads to low extraction efficiency and serious energy consumption in low-permeability oil fields,so the research and application of energy-saving and consumption-reducing technologies are of great significance for the development of low-permeability oil fields.In this paper,based on the construction of a multi-objective optimization model for low-permeability oil well exploitation,the multi-objective optimization solution is carried out with the objective of economic efficiency of oil well production to obtain energy-saving production parameters for low-permeability oil wells,and based on the obtained energy-saving production parameters,the energy-saving production control of the pumping system is realized based on the model predictive control(MPC)method.The main research contents of this paper are:Based on the single-well production control,construct a single-well daily production revenue sub-model and a single-well daily production energy cost sub-model for the two factors that have a large impact on the production efficiency in the production process of low-permeability wells,and use a Gaussian mixture model(GMM)to compensate for the error of the daily production energy cost sub-model,which effectively improves the prediction accuracy of the model.In the optimization process,a fast non-dominated ranking genetic algorithm(NSGA-II)is used to solve the model for the multi-variable and multi-objective characteristics of the low-permeability well production parameter optimization target model.The results show that the genetic algorithm is fast and of high quality in solving the multi-objective model,and the solution sets obtained are diverse,which can provide a reliable basis for the formulation of the well working system and the dynamic control of energy saving in the production process in real time.Based on the multi-objective optimization model,design a dual closed-loop model predictive controller with current and speed loops based on the mathematical model of the permanent magnet synchronous motor,and build a simulation model for simulation tests.The simulation results show that the dual closed-loop model predictive controller designed in this paper has better response and anti-interference characteristics than the traditional PI controller for the pumping machine permanent magnet synchronous motor control,and can dynamically regulate the production operation of the pumping machine system in real time based on the solution results of the multi-objective model.In order to verify the results of multi-objective optimization of production parameters of low-permeability oil wells and the effectiveness of energy-saving control methods,an experimental platform for low-permeability oil recovery control system was designed and built,and the control algorithm was embedded in the controller,and the pumping unit test system was used for energy-saving control experiments.The experimental results verified the response and anti-interference performance of the pumping machine dual closed-loop model predictive controller in the face of sudden load changes and dynamic regulation;and the low-permeability well oil production controller was installed and commissioned in an oil production plant in Changqing Oilfield.The production parameters and energy saving control method based on the multi-objective optimization results of this paper are more in line with the actual process of low permeability oil well development,which can significantly improve the energy saving effect and economic efficiency of oil well production.