عنوان مقاله [English]
Fluid behavior is very important in reservoir engineering regarding process design and field management and plays a key role in predicting hydrocarbon reservoir performance simulations. Dissolution of gas in oil may be the result of gas injection at pressures above the saturation pressure of a given oil provided that the system (gas-oil) is given enough time to reach equilibrium conditions. Gas injection into an under-saturated oil reservoir is a typical situation in which both gas dissolution and oil swelling are observed. Since the dynamic behavior of a reservoir under such a process can only be simulated using compositional reservoir model. Therefore oil swelling test should be carried out. The result of this test along with other PVT data were used to propose an equation of state (EOS). Due to precision of laboratorial procedures and also the hysteresis effect; a certain percentage of errors were inevitable. This study was done by applying an EOS to simulate oil-gas PVT changes.