Experimental Study and CFD Modeling of Two-phase Well-Head Separator

The performance of two-phase separator was investigated in this paper. Two-phase separator was designed and manufactured using empirical correlations. The simplifying assumptions were used in these empirical correlations which make the results of these empirical correlations less valuable. The effect of inlet diverter was neglected in designing methods and the diameter of the liquid droplets assumed to be constant and predetermined. In these designing methods, it was assumed that the liquid droplets were falling from the top of the two-phase separator vessel but in reality, the inlet diverter leads to separate the majority of liquid droplets because of momentum changing. Also, the fundamentals of the turbulent multi-phase flow were not considered in these designing methods. The two-phase flow loop was designed and manufactured. Air and water flows were mixed together at mixing section that was a 45° Tee and two-phase flow was formed. The two-phase flow had been considered as developed two-phase flow after passing 160*D distance along the pipe length which D is the pipe diameter. Water and air flow rates were in ranges of 0-2.5m3/h and 0-100m3/h, respectively. The liquid droplets trapper with 20-micron filter was mounted at gas outlet section of the separator to measure the volume fraction of the liquid phase in outlet gas flow and photography of liquid droplets in order to determine the diameter of the liquid droplets in outlet gas flow. The CFD results were validated using experimental results and compared together in order to obtain the best multiphase flow model, turbulent flow model and under relaxation factors. Finally, the dimensionless groups were developed in order to model and investigate the separator performance. One of the most important achievements of this paper was providing the suitable platform to design well head two-phase separators based on the production conditions.