establishing a mass balance on the oil and gas phases, following algebraic relations are obtained: (23) (24) (25) Density and fugacity is calculated at the pressure of From the definition of molar “P”. composition and saturation, the following relation is also obtained: (26) (27) (28) The above equations are used for performing the calculations of equilibrium flash vaporization. As we know, before performing these calculations, systems stability must be controlled and several methods have been proposed by researchers for stability control. Michelson stability test which is based on the method of tangent plate’s length determination is used generally and this length is calculated for a mixture of component as follows: “Nc” (29) shows the chemical potential. And in order to stability of the system, this parameter must always be positive. Pressure equation: To obtain the Pressure equation, the equation (7) is added to the equation (8): (30) Which in above equation is determined as follows: “a”
establishing a mass balance on the oil and gas phases, following algebraic relations are obtained: (23) (24) (25) Density and fugacity is calculated at the pressure of “P”. From the definition of molar composition and saturation, the following relation is also obtained: (26) (27) (28) The above equations are used for performing the calculations of equilibrium flash vaporization. As we know, before performing these calculations, systems stability must be controlled and several methods have been proposed by researchers for stability control. Michelson stability test which is based on the method of tangent plate’s length determination is used generally and this length is calculated for a mixture of “Nc” component as follows: (29) shows the chemical potential. And in order to stability of the system, this parameter must always be positive. Pressure equation: To obtain the Pressure equation, the equation (7) is added to the equation (8): (30) Which “a” in above equation is determined as follows: