Fluid Phase Behavior for Conventional and Unconventional Oil and Gas Reservoirs

4.2. Grouping Methods

Computational time required for phase behavior simulation increases considerably by increasing the number of components that are used for describing reservoir fluid. The number of sufficient pseudocomponents to describe reservoir fluid depends mainly on the process being simulated (Whitson and Brulé, 2000). For example, the number of sufficient components for the prediction of phase behavior of reservoir fluid under pressure depletion is two (Danesh, 1998) although simulation of miscibility in a slim-tube needs 12–15 components (Whitson and Brulé, 2000). Many authors (Jacoby et al., 1959; Lee et al., 1981; Hong, 1982; Whitson, 1983; Montel and Gouel, 1984; Gonzales et al., 1986; Schlijper, 1986; Chorn and Mansoori, 1989