Development Of Oil Well Energy Converter Based On Pulse Power Technology

Fossil energy is still the most important primary energy source in the world.The development of fossil energy reservoirs requires certain modifications to the reservoir rocks to exert pressure on the reservoirs,causing the reservoirs to rupture to concentrate more oil and gas.The traditional mining methods represented by hydraulic fracturing have the disadvantages of single impact,overall work and low efficiency.As a means of generating shock waves,electric explosion can convert electrical energy into controllable impact energy,and can improve rock formation structure and increase permeability.It is a highly efficient mining method.This dissertation intends to develop a device that can work underground,convert electrical energy into mechanical energy,and generate impacts to increase oil and gas well production.Hydroelectric effects and wire electrical explosions are two common methods of generating shock waves by electrical means.In order to understand the factors affecting the shock wave effect,a mathematical model of the liquid-electric effect described by the differential equations is established,and the influence of different parameters is deduced mathematically.The simulation results are used to verify the deduced results.The conclusion is that the higher the discharge voltage,the greater the impact strength.At the same time,process of electric arc explosion also divided into five stages,and the different characteristics of the differential equations for the five stages is described.The influence of different parameters are derived on the results from the mathematical point of view.Mathematical derivation was also carried out,and the results were verified by simulation.Finally,the higher the discharge voltage is,the more intense the discharge is,and the higher the discharge energy is.The advantages and disadvantages of the two shock wave generation mechanisms and the enforceability in engineering is compared in the third chapter.Finally,the liquid electricity effect is selected as the mechanism of shock wave.In order to complete the design of the downhole transducer,it is first necessary to determine the basic principle of generating pulse power.Marx generators and voltage doubler rectification are two common techniques in pulsed power technology.This dissertation briefly introduces the principle of Marx generator and voltage doubler rectifier circuit,and compares the advantages and disadvantages of the two technologies and the feasibility of the project,and determines the more feasible and low cost voltage doubler rectification as the basic principle of the pulse power.The charging characteristics of the voltage doubler circuit are analyzed,and the transient process during charging is studied.The relationship between the charging voltage and the charging frequency on the charging speed of the transducer is obtained.The experimental scheme of the performance of the transducer device is introduced.A detection system for collecting voltage,current and vibration signals is also designed to detect the discharge energy and discharge frequency of the transducer.By changing the charging voltage and charging frequency,the influence of the charging frequency on the discharge frequency was studied.The analysis of the charging characteristics in Chapter 4 was verified.The effect of the discharge energy on the discharge energy was studied by changing the discharge voltage of the main switch.