| With the development of conventional oil and gas resources,the high capacity oil and gas resources decrease year by year.The conventional development technology has been unable to meet the exploitation of unconventional oil and gas resources,and the unconventional oil and gas resources occupy a large proportion in the undeveloped oil and gas resources.The development practice of oil and gas fields both at home and abroad shows that the technique of radial horizontal wells based on lateral drilling of continuous tubing is very suitable for the development of low permeability,thin reservoir and fracture.The core element of radial horizontal well technology is jet nozzle,which not only can complete rock breaking and reaming alone,but also provide a forward moving traction force for high-pressure hose.Limited to such factors as rock breaking pressure,pipeline and equipment,the technology can only be completed under the condition of high pressure and small flow rate,which requires that the diameter of the jet nozzle is relatively small,and the configuration parameters of the nozzle are relatively reasonable with the parameters of the jet.At present,there is still no systematic method for parameter optimization of jet nozzle.In view of this situation,in this paper,parameters of sprinkler head are optimized by using commonly used direct flow nozzle,and the parameter matching scheme of sprinkler under different conditions is obtained.To this end,the main work of this article includes:Firstly,the theoretical analysis of the number and arrangement of the nozzle of the jet nozzle is carried out,and the fluid simulation software FLUENT is used to verify it.Secondly,the simulation and comparison of the inlet shape of the nozzle,the shape of the broken rock nozzle and the ratio of the length to diameter of the nozzle are carried out.The influence of the jet parameters of the nozzle on the position design of the lateral rock breaking nozzle and the optimum jet distance of the nozzle is analyzed theoretically.Based on the self-propelled direct flow nozzle model,the force analysis of the sprinkler head is carried out,and the formula for calculating the self-propelled force of the sprinkler is deduced,which is related to the parameters of the jet,and the correctness of the formula is verified and analyzed.According to the distribution rule of nozzle outlet velocity after self-propelled nozzle jet simulation,the calculation method of average nozzle outlet velocity after nozzle jet simulation is derived.Considering the size of the nozzle under the theoretical calculation of the into force and the average speed of nozzle exit after the numerical simulation calculation method,designed the multiple sets of single variable under different jet parameters of the numerical simulation research into the nozzle model,the optimum parameters of nozzle jet of the self-propelled force,and the optimum range of parameters is verified.Based on the best jet parameters of nozzle since into the force value of nozzle jet parameters optimization research further,in both nozzle into force and broken rock nozzle exit velocity under the condition of large narrowed nozzle jet parameters values.The parameters of the self-propelled nozzle are optimized through the combination of several sets of theory and numerical simulation.Finally,the matching jet parameters of different sprinklers are obtained.The research work of the paper is mainly focused on the systematic optimization of the key parameters of the sprinkler.The theoretical analysis and simulation software CFD are combined to optimize the nozzle parameters.The research methods and results of this paper provide theoretical guidance and reference for the design of the structure parameters and jet parameters. |
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