Abstract: Mechanistic studies of vortex drainage gas recovery are insufficient and cannot effectively create guidelines for field application.What is lacking is an analysis that aims to research the influence of the structure parameters of the vortex tool on the drainage effect.Therefore,based on the theory of similarity,physical simulation experiments were designed and the experimental facilities were set up.Then impact of installing the vortex tool were examines,namely the wellbore pressure drop and the flow rate curves.Later,the influences of helical flow channel scale,sealing on both sides of flow channel and helix angle of vortex tool on the drainage effect were analyzed.It was possible then to determine the critical flow rate after installing the optimized vortex tool.The theoretical model for calculating the optimal helical angle was established based on the two-phase fluid dynamic theory.The experiment showed that the drainage effect of vortex tools could be improve while enhancing the leak-tightness and decreasing the size of the flow channel under the conditions of low wellbore pressure drop.The experimental optimal helix angle was 45°,which was in good agreement with the results of the theoretical model;after installing the optimized vortex tool,the wellbore pressure drop would decrease by about 9.6%,the liquid flow rate would increase by about 12.4%,and the critical flow rate would decrease by about 20%.The optimized vortex tool enhanced the drainage capability and the results of optimal theoretical model for helix angle were reliable,thus providing theoretical guidance for design and field application of the vortex tool.