Analysis of Transient Gas-Liquid Two-Phase Flow in Pipelines

A new method is developed to analyze transient gas-liquid two-phase flow in natural gas pipelines. This method utilizes the two velocity mixture model to derive the basic equations. Also, a new model, which expresses phase conditions for multicomponent natural gas-condensate system, is presented to derive mass conservation equations for each hypothetical component. Transient air-water two-phase flow experiments were conducted using a test pipeline 105.3 mm in diameter and 1436.5 m long. Experimental conditions include, increasing or decreasing air flow rate with constant water flow rate, and transition from single-phase air flow to air-water two-phase flow. Experimental data were compared with calculated results, and the agreement was very good. Furthermore, calculated results agreed very well with a published field data.