Study on Feasibility of the Vortex Tool for Gas Well Fluid Drainage in Different Flow Regimes

At present, the mechanism research of vortex tools in China mainly uses Fluent software to simulate the flow field, which ignores the actual flow regime distribution in the wellbore and the applicability of the vortex tool in each flow regime, leading to unclear understanding of the mechanism of the vortex tool. In order to study the dynamic behavior of fluid in the vertical pipe before and after passing through the vortex tool under the slug flow, the agitation flow and the annular flow, the transient simulation method of Fluent software is used to analyze the flow field change and explain the working mechanism of the vortex tool and the feasibility in each flow regime. The analysis results show that the main mechanism of the vortex tool is to transform the fluid energy, namely converting part of the static pressure into dynamic pressure. The increment of dynamic pressure is used to provide the fluid tangential velocity to effectively separate gas-liquid. Compared with the slug flow and the annular flow, the liquid holdup of the agitated flow after passing through the vortex tool is reduced, thus effectively improves the liquid carrying capacity of the gas. Therefore, the agitation flow is preferable for the vortex tool. The research results could provide references for the field application of vortex tool for gas well fluid drainage.