This mode allows users to calculate the liquid dropout curve for a gas condensate reservoir fluid as a function of pressure at constant temperature.
This mode computes the liquid dropout curve for a gas condensate reservoir fluid at a specified temperature. PRO/II produces tabular results and a printer plot of pressure versus the percentage of liquid volume produced by the flash with respect to the volume occupied by the vapor at its upper dew point saturation pressure or at any higher pressure (e.g., reservoir pressure).
Reference Temperature These specify the reference conditions (pressure and temperature) for the computation. Reference temperature defaults to the merged feed stream temperature.
Reference Pressure This reference pressure defaults to the dew point pressure. In this mode, users often specify reference pressure as the reservoir pressure. During calculations, if the specified value is lower than the dew point pressure, PRO/II uses the dew point pressure instead of the supplied value. The user-specified value of reference pressure is not changed internally, but a warning message is issued to alert the user.
End Pressure Specifies the lowest pressure for the DROPOUT calculations.
Number of Points or Pressure Increment These entries specify how PRO/II determines the pressure values to use for the computation. The user may define either the number of points (N, where N <100) or a specific step size between consecutive pressure values (pressure increment).
PRO/II determines the actual pressure values between the reference pressure (or perhaps the dew point pressure) and End Pressure based on the number of points or increments.
Experimental Data Grid
Pressure / Liquid Dropout / Weighting Factor Grid
This grid accepts the experimental pressure, the corresponding percentage of liquid volume with respect to the volume of the gas at reference conditions, and the weight assigned to each experimental data point (this value is optional and defaults to 1.0). Based on these experimental data points, PRO/II computes the absolute and relative differences between the experimental and calculated value for each data point and reports the weighted sums of the squared absolute and relative errors as AERR and RERR, respectively. These errors, as well as the dew point pressure, are accessible to the CALCULATOR, CONTROLLER, MVC, and OPTIMIZER, allowing the user to tune thermodynamic parameters to match the experimental data.