Enhancement of the Drift-Flux Model for gas-liquid slug flow in a long vertical pipe

The paper presents an Averaged Drift-Flux Model (ADFM) facilitating consideration of the internal structure of the gas-liquid slug flow in a vertical pipe. Modulation equations are used for flow parameter averaging. The allowable domain of the ADFM has been determined and its difference from the conventional model has been demonstrated. The specific features of the developed model for frictional and frictionless steady state flow patterns have been considered. The averaged model has been verified by comparing the calculation results and the results of three experimental studies. The proposed paper is aimed at expanding the capabilities of the Drift-Flux Model class. The model is oriented on advanced hydrodynamic calculations in oil and gas wells and risers.