TABLE OF CONTENTS The hydraulic design of a multiphase flow pipeline is a two-step process. The first step is the determination of the multiphase flow regimes because many pressure drop calculation methods rely on the type of flow regime present in the pipe. The second step is the calculation of flow parameters, such as pressure drop and liquid holdup, to size pipelines and field processing equipment, such as slug catchers.
The techniques used most commonly in the design of a two-phase flow pipeline can be classified into three categories: single-phase flow approaches, homogeneous flow approaches, and mechanistic models. Within each of these groups are subcategories that are based on the general characteristics of the models used to perform design calculations.
In this method, the two-phase flow is assumed to be a single-phase flow having pseudo-properties arrived at by suitably weighting the properties of the individual phases. These approaches basically rely solely on the well-established design equations for single-phase gas flow in pipes. Two-phase flow is treated as a simple extension by use of a multiplier: a safety factor to account for the higher pressure drop generally encountered in two-phase flow. This heuristic approach was widely used and generally resulted in inaccurate pipeline design (Dukler, 1969; Oranje, 1973; Schewikert, 1986).
In the past, single-phase flow approaches were used commonly for the design of wet gas pipelines. When the amount of the condensed liquid is negligibly small, the use of such...
