Analysis on the multiphase flow rules of bit nozzle of ultra-short radius horizontal well

Abstract：In order to solve the contradiction between borehole diameter and the depth of borehole of high-pressure jet drilling in ultra-short radius horizontal wells,on the basis of considering the inter-phase forces both liquid phase and solid phase,used the continuum medium,according to the liquid-solid two-phase two-fluid model,the liquid-solid multiphase jet in bit nozzle of ultra-short radius horizontal well was simulated and investigated,and the results were contrast with the same single-phase jet.The results show that the velocity distribution trends of liquid phase axis in single phase and multiphase two cases are basically the same,but when the liquid flow into the straight cylinder segments of the nozzle and move to the export gradually,the liquid-phase axis speed of the single phase jet is lower than the multi-phase liquid.On section of the nozzle export,axis is closer,the liquid-phase velocity is nearer in the both cases,the wall is closer,and the difference of the liquid-phase velocity is greater in both cases.Solid particles exist the velocity ahead sliding phenomenon in the inner wall of the nozzle.On axis of the nozzle,the intensity of turbulence have the same development trend in both cases,when the liquid flow into the straight cylinder segments of the nozzle and move to the export gradually,the intensity of turbulence of the single phase jet is higher than the multi-phase liquid.