Research On The Control Strategy Of Electric Workover Rigs Power System Based On Supercapacitors

The workover rig,which is responsible for solving downhole failures,is one of the most critical equipment in wellsites maintenance operation.The operating system of traditional workover rigs is powered by diesel engines of walking system,and adopts mechanical-hydraulic transmission to drive the roller rotation stably.The disadvantages of traditional workover rigs include power mismatching,low efficiency,serious pollution,low automation degree and high labor intensity.The research on electric workover rigs can solve the above problems.However,the ability of network workover rigs has been greatly limited by the capacity of wellsite power grids.In order to resolve the contradiction,a kind of power compensation system based on supercapacitors is proposed in this paper,and the traditional joysticks are simplified as pushbuttons.At the same time,the power compensation control strategy and speed control strategy are developed.Based on this,system model is built and the control code is generated according to the V process.At last,the test platform is established to verify the feasibility of control strategy.The specific structure of the paper is as follows:(1)The design of the workover rig power compensation system based on supercapacitors.The characteristics of workeover cycle conditions are firstly analyzed to achieve power compensation by taking supercapacitors as energy storage elements.The strong electricity circuit,weak electricity circuit and communication circuit are designed and calculated,and the capacity configuration of supercapacitors is determined.(2)The development of power compensation system control strategy.According to the demand of power in each workover operation,the power compensation control strategy and the charging/discharging method are developed to control the power flow.Based on the frequency conversion control technology,the speed control strategy of power compensation system is developed to simplify the operation,improve the efficiency and automation degree of workover.(3)Model building and simulation analysis of power compensation system.The system model is built and simulated based on Matlab/Simulink and Simscape module.Strong electricity circuit model,power compensation control strategy model and speed control stategy of power system are analyzed and simulated.The simulation results of different operations verify the feasibility of control strategies preliminarily.(4)Verification on the speed control strategy of power compensation system.The test platform for the speed control strategy of power compensation system is established to simulate the working conditions of the workover rig and verify the feasibility of driller’s operation.The experimental results show the feasibility and applicability of the speed control strategy.In this paper,the reasonable distribution of power flow is achieved through the research on the design and control strategy of the workover rig power system.The final experimental results prove that the speed control strategy can achieve the adjustable-speed function in workover operation,improve the work efficiency and automation degree.The research and achievements,which provide technical solutions for the development and application of electric workover rigs in this paper,promote the electrification and semi-automatic process of workover rigs,and have practical application prospects.