Study of gas condensation in transmission pipelines using a hydrodynamic model

Liquid condensation is a common occurrence in pipelines used in transporting natural gas over substantial distance. In such pipelines, the percentage of liquid varies very widely depending on the composition of the transported gas, pressure and temperature conditions as well as the hydrodynamic behavior of the system. The problem is further complicated by undulating terrain subjecting it to varying inclinations. Performance design must incorporate the hydrodynamic of the resulting two-phase system. This study presents a viable model developed for this purpose. The resulting compositional hydrodynamic model is used to predict such important variables as the pressure drop, quantity of liquid, pressure and liquid holdup profiles, and gas/liquid flow rates. Such engineering variables are important in the optimal location of the liquid catchers, compressor, separator, etc. The integrated phase behavior model is developed using a modified Peng-Robinson equation of state.