Research And Optimization Of The Structure Of The Blasting Perforator For Coiled Tubing Operation

CT-employed(Coiled Tubing)hydrajet perforation technology has been widely used in the well-completion industry.With the increase in the depth of the application of the technology and the complexity of the application of the layer,the condition of the down-hole tool is becoming more and more complex.As for low-permeability,ultra-low permeability and thin reservoirs,the existing hydrajet perforation nozzle has been unable to meet its more harsh operating conditions,with the operation going on,the nozzle jet performance and life are seriously affected,which is not conducive to the smooth well-completion.Therefore,it is very important to analyze the mechanical properties of the nozzle,and it is very important for the wide application of hydraulic blasting perforation technology to improve the jet performance of the nozzle.Although the domestic and foreign scholars have done a lot of research for the nozzle of the working conditions and jet speed,most of the research are aimed at the size of the traditional nozzle structure,which just using simple experience to get the value,and to improve the efficiency of rock breaking,but ignoring that when the change in the size happens,the nozzle jet-intensive performance will also be affected.Therefore,this paper analyzes the mechanical properties of the nozzle in the process of jetting,and puts forward some evaluation indexes which affect the jet performance of the nozzle.Then,by combining the advanced numerical optimization method and the finite element simulation analysis,using the PIAnO integrated optimization platform parametric modeling,experimental design and optimization design,the optimization process of the nozzle structure is established,the rigorous mathematical process is substituted for the human experience,the optimization direction of the nozzle is controlled,and the jet performance of the nozzle is further improved.The specific analysis and optimization process and method are as follows:(1)The finite element model of the most widely used cone jet nozzle was established,and the mechanical properties and energy loss of the nozzle were analyzed.At the same time,the nozzle performance index and evaluation method were determined.(2)The parametric calculation flow of the cone-shaped nozzle jet is established,the sensitivity of the nozzle structure is analyzed by the experimental design method.The relationship between the nozzle performance and the nozzle structure parameters is obtained,and the range of the design variable is narrowed,on this basis,the multi-objective optimization of the geometric size of the cone-shaped nozzle is completed,and the optimal size combination scheme of the traditional cone-shaped nozzle is obtained.(3)The finite element model of the dual-taper nozzle and the jet simulation process are established.Then,the numerical optimization design of the dual-taper nozzle is carried out,and the optimal size of the dual-taper nozzle is optimized to find the optimal size scheme.In this paper,a new analysis and optimization method is proposed to improve the jet performance of the nozzle in the continuous operation of the hydraulic blasting process.The jet performance of the nozzle is improved by improving the jet velocity and the jet density.A new type of double taper nozzle model is proposed,which has some reference significance for the optimization of the nozzle.