چكيده به لاتين
Abstract:
Phase equilibrium study is one of the most important tools in development of production in petroleum reservoir. Knowledge of vapor liquid equilibrium data for understanding separation process and also surface equipment is so important. Having composition of gas and liquid comes out of separator we can calculate Overall composition of petroleum mixture mass balance. For data gathered and used in this study, composition of gas and liquid determined by gas chromatograph and micro distillation tower, respectively. Because micro distillation tower has low accuracy in determination of liquid composition, there is always error in calculation of oil mixture overall composition. In this study experimental data of liquid phase composition has been modified to have correct liquid phase composition and overall composition of oil mixture. For determination of thermodynamical vapor liquid ratio in hydrocarbon mixture three method is used: empirical diagram, empirical correlation and equation of state. Method of empirical diagram is fast and give us a proper value for vapor liquid ratio. Using EOS for determination of vapor liquid ratio is more complicated and needs to programming. In this study, experimental data for gas and liquid phases composition had been gathered. Then using Peng-Robinson EOS modified by Feyzi et. al. and doing phase equilibrium calculation and regression of binary interaction parameter, vapor liquid equilibrium ratio has been calculated. It has been observed that for all component in the mixture vapor liquid equilibrium ratio decreases with increase of pressure. Shuffled complex evolution algorithm has been used for optimization of EOS parameter. Result of vapor liquid equilibrium ratio calculation has been compared with some empirical correlation. Trend of variation for vapor liquid equilibrium ratio is similar to values from empirical correlation but we can’t trust on empirical correlation because effect of component composition in the mixture is neglected in this correlation.
Keyword: equilibrium ratio, vapor – liquid equilibria, binary interaction parameter, hydrocarbon, petroleum reservoir
