Phase Behavior of Petroleum Reservoir Fluids in the Dense Phase or Supercritical Region

In the context of normal or broad reference made to petroleum reservoir fluids, terms such as vapor, gas, or liquid are commonly used because of a particular state of existence in the rock pore spaces, production tubing, surface processing facilities, and pipelines. This chapter explains the effect of temperature and pressure on two specific physical properties, that is, density and viscosity of pure CO₂ and the rich natural gas mixture in the dense phase region and compares them with other regions to highlight the differences. It shows that density and viscosity is because of their unique characteristics that are of particular practical importance when transporting fluids in the dense phase region. The chapter provides the practical significance of dense phase fluid, the specifics and some examples. It investigates the placement of the hydrate equilibrium curve with respect to the phase envelope and the dense phase region for several diverse multicomponent systems.