Research Of Impulse Discharging Apparatus Applied To Plug Removal Of Oil Wells

After the oil well is developed for a period of time,impurities such as mud particles or organic dirt block the pore passage,reduce the permeability of the oil layer,reduce the oil production and injection volume,which seriously hampers the development and utilization rate of the oilfield.Traditional strong acids,explosives,pressure and other methods has a great influence on the environment.The low-frequency pulsed strong shock wave technology based on the principle of high power pulse technology can partially replace the original method of plugging.The technology is based on the liquid-electric effect,the electrical energy is converted to shock wave mechanical energy,repeated treatment of underground reservoir plugging.Due to the limitations of well size,high-temperature and high-temperature conditions in underground wells,and the specifications of well cables,the design of downhole electrical pulse plugging device is subject to many conditions In this paper,the charging and discharging process and its key technologies are studied in detail.Combined with the existing conditions,an impulse discharge device for 25 kPa / 40 mA and 5 kJ energy storage for plugging is designed.The main work of the full paper is as follows:(1)Through the physical process of plasma discharge channel research,combined with the equipment working environment,determine the electrical properties of impulse discharge equipment and the use of environmental requirements.(2)Designed the main circuit of equipment charging.The LC resonant constant-current charging circuit is analyzed in detail,and the soft switching scheme with the switching frequency less than half the resonant frequency is selected.The simulation results show that the energy storage capacitor of 16,from 0kV charge to 25 kV with constant current.(3)Designed a high-frequency transformer.Select TDK's N27PM87 / 70 core;the single transformer diameter 87 mm,height 70 mm,ratio 459: 5000;500V,2000 Hz square wave is boost rectified to 25 kV,0.06 A DC power supply for the capacitor charging by cascade program.(4)Design a polyphenylene sulfide film capacitors that Withstand voltage 30 kV,15.9,diameter 80 mm,length of about 3.5m.(5)The transducer of "column-column" discharge electrode and paraboloid of revolution is designed.Starting from the physical process of the discharge channel,a reasonable electrical demand is obtained,designed the circuit,and the circuit modules are analyzed and simulated.The selection of standard devices,designed for the device of non-standard devices,focusing on the design of high-frequency transformers,capacitors,discharge electrodes and energy concentrator hood and other key components.Finally,an oil well plugging impact discharge equipment is designed which can meet the requirements.The equipment output 25kV/ 40 mA constant current direct current,single discharge 5kJ,underground equipment length 5.5m,diameter 114 mm,working depth 3km.The equipment developed in this paper has higher single release energy.The key technologies of the equipment are analyzed theoretically and simulated in detail.In this paper,the electrode and the energy accumulator structure are independently designed.