TABLE OF CONTENTS Gas/condensate flow is a multiphase flow phenomenon commonly encountered in raw gas transportation. However, the multiphase flow that takes place in gascondensate transmission lines differs in certain respects from the general multiphase flow in pipelines. In fact, in gas/condensate flow systems, there is always interphase mass transfer from the gas phase to the liquid phase because of the temperature and pressure variations, which leads to compositional changes and associated fluid property changes (Ayala and Adewumi, 2003). In addition, the amount of liquid in such systems is assumed to be small, and the gas flow rate gives a sufficiently high Reynolds number that the fluid flow regime for a nearly horizontal pipe can be expected to be annular-mist flow and/or stratified flow (Boriyantoro and Adewumi, 1994; Asante, 2002). For other inclined cases, even with small quantities of liquids, slug-type regimes may be developed if liquids start accumulating at the pipe lower section.
In order to achieve optimal design of gas/condensate pipelines and downstream processing facilities, one needs a description of the relative amount of condensate and the flow regime taking place along the pipelines, where fluid flowing in pipelines may traverse the fluid phase envelope such that the fluid phase changes from single phase to two phase or vice versa. Hence, compositional singlephase/multiphase hydrodynamic modeling, which couples the hydrodynamic model with the natural gas-phase behavior model, is necessary to predict fluid dynamic behavior in gas/condensate transmission lines. The hydrodynamic model is required to obtain flow...
