Simulation And Design Method Of Vortex Flow Tools Used For Unloading Liquid In Gas Wells

Previous research about the vortex tool show that it can effectively unload liquid in stripper gas wells by lowering the Turner critical velocity requirement by 30%.Practical application however show that it is difficult to achieve the desired effect,which limits the application of the downhole vortex tools in the oil and gas industry.Therefore,it is necessary to understand the vortex tool mechanism of unloading stripper gas well using the liquid film model.This paper compares the droplet model and liquid film models for annular flow regime,explains the working principle of the vortex tool and establishes a condition for critical flow based on a new film model that was developed.Also,using numerical simulation flow pattern generated by the vortex tools is studied and geometry optimized.Following extensive literature research and graphic analysis,the vertical annular flow was studied which established a new model for critical velocity based on the liquid film.Then,numerical simulation of the vortex tools,using Gambit2.4.6 to design the geometry of the model and mesh,and Ansys Fluent 15.0 to output the results of the flow characteristics was done.From the study of the vertical annular flow,calculated data showed that the critical velocity based on the liquid film is lower than the critical velocity by the droplet model.Liquid film analysis resulted in formulation of a new critical velocity film model.Numerical simulation results showed that the vortex tools generate a spiral form of flow.A centrifugal force generated by the flow through the vortex tools works to accelerate the mixture upwards,with the gas concentrating in the core and the liquid distributed on the inner wall of the pipe.The distribution of the velocity of the gas core showed that it is slightly lower in the center than near the pipe wall.A vortex tool length 127 mm,blade length of 63.5 mm gave the best condition for the annular flow.