Optimization of structural parameters for fluid-carrying swirl tool in gas wells

A study was made on structural optimization of swirl tool to enhance operation efficiency of the swirl fluid-discharging and gas-producing tool in gas wells. AutoCAD and Fluent fluid simulation software were used in the study to build a flow field model for gas/liquid in swirl tool. In addition, orthogonal test was performed to clarify the program for simulation and calculation. Through variance and range analysis, impacts of four structural parameters (i.e. lead, number of leads, trough depth and trough width) on peak velocity at outlet of the tool were determined together with optimal structural parameters for such tool. The results show that minor trough depth and width, together with large lead and number of leads can effectively enhance velocities. With trough depth of 5 mm, trough width of 40-45 mm, lead number of 3 and leads of 172-219 mm, the maximum velocity of gas from gas/liquid mixture through swirl tool with the most desirable fluid-carrying capacity can be obtained. Impacts of structural parameters of such tool on the maximum outlet velocity may vary with conditions of gas/liquid. With relatively high liquid/gas ratio, higher number of leads may effectively enhance the velocity. With relatively high velocity at inlet, smaller trough width may obviously increase the velocity. Besides, larger leads may have insignificant impacts on increase in velocity. Smaller trough depth may constantly display obvious impacts on enhancement of velocity.The study results may provide necessary references for selecting optimal swirl tools and promoting performances of such tools on site.