Study On Wireless Power Transfer Technology For Downhole Engineering

Most of the power transmission are carried out by the way of wire.Getting rid of the constraint of tangible medium,and realizing the wireless power transmission are purse for many years.During the development of oil and gas fields,measurement of downhole formation parameters and formation fluid control is the key to efficient development of oil and gas.In pracfice,we often use electronic device without cables to adjust the formation flow and measure parameters when it is no need to regulate the downhole flew and colleet real-time data.However,these cableless electronic devices they need to be supplemented with electricity after working some time underground.Therefore.it is crucial in practice to study technology of downhole wireless power transmission.Considering the actual requirements of downhole wireless power transmission in oil and gas,this paper has developed a downhole wireless power transmission device through analysis,design,testing,and improving.The main work and research results are as follows:Firstly,.this paper analyzed several electromagnetic energy transmission methods such as electromagnetic induction and magnetic resonance having been applied to the ground reality.Taking into account the electrical needs of the downhole electronic devices,the technical complexity and the requirements of the downhole working environment,a wireless energy transmission principle scheme suitable for downhole electronic devices was proposed and verified by tests.Secondly,four sets of transmission coils and receiving coils were designed and made for downhole wireless power transmission with different structural parameters.The relationships among the coil structure,number of turns and transmission power,transmission efficiency and transmission distance were experimentally studied.The transmission and receiving coils with suitable parameters were chosen.Thirdly,wireless power transmission device was generally designed.The SPWM inverse circuit and its control program,rectifier circuit,transmitting circuit,receiving circuit and other functional modules were given,and a prototype of downhole wireless power transmission was made.Finally,the prototype was tested by simulating the downhole working environment,and the circuit and software were improved during the test.The research results of this paper are expected to be applied to downhole cableless measurement and control electronic devices.