ABSTRACT
Naturally occurring petroleum reservoir fluids (including the aqueous phase), from which most solids originate, are somewhat complex mixtures of different components present in varying amounts. The complexity exponentially increases with higher carbon numbers, thus necessitating a proper characterization of what is known as the plus fraction, since discrete identification of each and every component is of little value and not practically feasible. For effective management of flow assurance activities, an understanding of the chemical composition of petroleum reservoir fluids is routinely carried out in terms of well-defined components, pseudo-carbon numbers, and an (extended) plus fraction. Following the compositional description, the knowledge about the behavior of these fluids under various temperature and pressure conditions is also equally important. The laboratory techniques and calculation methods pertaining to these aspects are covered in this chapter.
