A Mechanistic Study on Minimum Flow Rate for the Continuous Removal of Liquids from Gas Wells

Abstract

Experimental studies show that liquid drop is deformed from initial sphere shape into oblate spheroid shape in parallel air flow, and experimentally determined values available of critical Weber number We_crit vary from 2.2 to 60 in low-viscosity liquid. Based on forces equilibrium, the authors deduced a new model to predict minimum flow rate. The model introduces a parameter C_k,Wecrit that describes the effect of liquid drop deformation and the maximum drop size difference on minimum flow rate. A function to predict drop deformation magnitude for different critical Weber number is developed based on energy conservation. The function prediction results are in good agreement with experimental data given in the literature and the predicted result from the DDB model, and the deviation is less than 6%. The C_k,Wecrit calculated by new model changes from 2.44 to 4.79, and the C_k,Wecrit calculated from data from gas field and experiment changes from 1.86 to 5.0. The new model theoretically explains the reasons that the discrepancy of the minimum flow rate is significant and minimum flow rate in some gas wells in China are low.

Keywords:

• critical gas flow rate
• critical Weber number
• entrained droplet model
• liquid drop deformation
• liquid loading