PVT and Phase Behavior of Petroleum Fluids

Flow assurance can be expressed as the coupling of multiphase flow and fluid phase behavior. It requires understanding multiphase flow as well as fluid properties, fluid compositions, pressure-volume-temperature (PVT) characteristics, and other fluid phase behavior from the reservoir to the downstream processing facility through the life of the field to prevent upset conditions. A good understanding of the phase behavior and fluid properties allows a flow assurance engineer to develop technically feasible and economically optimal set of strategies to overcome a variety of flow assurance problems, ensuring a successful and safe operation. In this chapter, after a short review of the nature and chemistry of petroleum fluids, the thermodynamic behavior of pure compounds and the various types of reservoir fluids will be described. A section is then dedicated to laboratory thermodynamic experiments such as PVT analysis and finally some empirical correlations and equations of state used to simulate the phase behavior of the hydrocarbons and calculate thermophysical properties will be presented.