Evaluation of flow characteristics in an onshore horizontal separator using computational fluid dynamics

In the petrochemical industry, separation of oil from water is a very important process. Wells produce mixtures of gas, oil, and water which undergo a primary stage of separation inside horizontal gravity separators. The performance of these vessels is evaluated by measuring mean residence time (MRT) and residence time distribution (RTD). Although many researchers studied flow characteristics in horizontal separators, limited number of articles exist that discuss separator MRT and RTD with varying water-cuts. In this article, the authors study an experiment using a horizontal gravity separator by previous researchers and perform computational fluid dynamics (CFD) simulations on the same geometry under similar conditions. The simulation results show qualitative agreement with the experiments by previous researchers. As shown by experiments before, CFD results showed that MRT of the organic phase increased with increase in water-cut. In addition, the RTD characteristics show very similar trends between CFD and experimental results.