Research On Self-Power Generation Technology In Water Injection Wells

The research on the downhole self-power generation technology of the water injection well is a self-power generation system designed according to the channel structure of the water injection well and the complex environment of the underground with the downhole turbine generator as the core.According to the unique characteristics of the water injection well,the system realizes the conversion of energy from kinetic energy to mechanical energy and finally to electrical energy.The system has a complete self-generating structure,which effectively solves the problem of difficult power supply when the instrument is working,and provides a reliable power guarantee for energy extraction.First of all,by investigating the research status of a large number of domestic and foreign turbine generators,this paper uses the analogy method to design a turbine generator specially suitable for water injection downhole according to the mechanical structure of two common downhole mud generators and the characteristics of water injection channels.Secondly,the mechanical structure of the outer rotor and inner stator of the generator is modeled,and the finite element simulation technology is used to verify its electromagnetic performance.At the same time,in order to better supply power to the downhole instrument,the corresponding rectification,filtering,and voltage stabilization circuits are designed,and on this basis,protection measures are proposed for possible overvoltage and overcurrent problems.Finally,the design,processing and optimization of some components in the design process of the generator are carried out,and the prototype trial production and indoor fluid test are completed.At the same time,the selection of underground high temperature energy storage batteries and the analysis of charge and discharge characteristics are completed by using the comparison method,and a control system of the generator to the battery pack is designed by using the combination of software and hardware.The results show that the system is feasible from the design of mechanical structure to finite element simulation and subsequent circuit design.The indoor fluid test data show that under the indoor flow of 50m~3/d,the output power of the generator is 11.76w,which achieves the established goal(50m~3/d water injection output 10w electric energy).At the same time,the selected high-temperature rechargeable battery can adapt to the underground environment and can work for a long time.The final design of the charging control system can realize that when the battery pack power is less than 30%,the generator works to charge the lithium battery pack.When the battery pack is fully charged,the battery pack supplies power to the downhole instrument.The research on downhole self-generation technology of water injection wells provides technical guarantee for the intelligent and automatic research of intelligent separate injection technology of water injection wells.