Understanding the behavior of fluids in a reservoir is essential for achieving optimal design and operations in a petroleum processing plant. Augmented by the authors’experience with challenging conditions, this work details industry-standard methods for modeling phase behavior of petroleum reservoir fluids at various stages. Keeping math to a minimum, the book discusses sampling, characterization, compositional analyses, and equations used to simulate various pressure-volume-temperature properties. Developed in conjunction with several oil companies, the authors present new models for the characterization of heavy undefined hydrocarbons, transport properties, and solids precipitation.