Modeling of reservoir processes like gas miscible flooding may require consideration of phase equilibrium between multiple liquid phases. Under certain conditions two hydrocarbon liquid phases may form; one may also want to account for mass transfer between the hydrocarbon and the aqueous phases.

This paper describes a refined successive substitution (SS) method for calculating multiphase flash equilibrium. The phase behavior procedure proceeds in a stepwise manner, and additional phases are introduced by a special testing scheme based on phase fugacities. This is to avoid trivial solutions and to ensure continuity across phase boundaries.

The method has been tested on various three- and four-phase systems, and examples of application show that the method performs well.

Keywords:
water phase, liquid phase, phase behavior, fraction, equilibrium calculation, mole fraction, calculation, droplet, pvt measurement, equation
Subjects:
Fluid Characterization, Gas-injection methods, Improved and Enhanced Recovery, Phase behavior and PVT measurements, Reservoir Simulation
Copyright 1984, Society of Petroleum Engineers
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