The applicability and accuracy of a new binary pseudo-component PVT representation relative to conventional black-oil and equation-of-state representations is determined. This PVT representation extends the conventional black-oil treatment by decoupling the reservoir and surface PVT properties and. by modeling the properties of oil and gas through the use of K-values and Z-factors for a two component system.
Processes considered include depletion, water injection, and gas injection in oil reservoirs. In depletion simulations the ability of the two-component K-value (2CKV) representation to model gas phase condensation in surface separators results in higher and more accurate (relative to equation-of-state predictions) oil recovery predictions than those obtained using a conventional black-oil model. The capability of the 2CKV formulation to model time-dependent separator conditions is shown for a waterflood in a vertical cross section. Neither the 2CKV nor the black-oil formulation can accurately simulateds a gas injection process when the composition of the injection gas is significantly different from the composition of equilibrium reservoir gas in the injection cell(s).