Design And Test Of Downhole Resonant Wireless Power Transmission System

Separate zone production technology is one of the most important technical means to improve the efficiency of oilfield production in the world,and the intelligent valve is an important tool of separate zone production technology.The power supply mode of the intelligent valve is generally to use battery power.However,due to the limited battery capacity,when the battery energy is consumed to a certain level,the intelligent valve needs to be suspended and get out of the ground to replace the battery.Using wireless power transmission to supply power to the intelligent valve can not only avoid battery replacement,but also ensure the continuity of the intelligent valve operation and improve the efficiency of oilfield production.Therefore,this article takes the wireless power supply of the intelligent valve as the research background,and carries out the research on the downhole resonant wireless power transmission system.This article first designs the overall composition and mechanical structure of the downhole resonant wireless power transmission system based on the basic principles of wireless power transmission technology,the mechanical structure of the intelligent valve,and the space structure and environmental conditions of the downhole.Then,according to the system design,establish the multi-physics simulation model and equivalent circuit model of the system,and use the multi-physics modeling simulation software and mathematical software to analyze the transmission characteristics of the system.In the resonance state of the system,complete the optimized design of the system coil,so that the transmission efficiency of the system is effectively improved.Finally,design the hardware circuit of the system,and build an experimental prototype of the system for experimental testing.In the relevant experimental tests of the system,this article first carried out two groups of resonance experiments with different coil structures but the same mutual inductance between the coils.When the system output power of the asymmetric coil structure in the experiment reaches the peak value of 8.39 W of the system output power of the symmetric coil structure,the system transmission efficiency of the asymmetric coil structure is 26.88% higher than that of the symmetric coil structure.The experimental results show that when the system output power of the asymmetric coil structure is equal to the peak value of the system output power of the symmetric coil structure,the asymmetric coil structure can obtain a system with higher transmission efficiency than the symmetric coil structure.Then,a dislocation experiment of the system device was carried out.The experimental results showed that the dislocation of the device would cause a waste of system power.Therefore,it is necessary to avoid the occurrence of device dislocation in practical applications.