Slug catcher multiphase CFD modeling: Optimization and comparison with industrial standards

In the oil and gas industry, the traditional procedure for slug catcher design is based on the Stokes' law. Design equations are obtained from a 1-D analysis and validated with experimental data. Therefore, this method basically relies on simplified models and empirical correlations. For this reason, an over margin factor from 20 to 40% is usually applied. In this paper, a simplified CFD procedure for the modelling of the gas-liquid separation is presented. Steady state and transient models have been considered for single phase and multiphase fluids, using OpenFOAM. The influence of flow model and mesh grid on results have been evaluated as a trade-off between solution accuracy and computational efforts, in order to assess the applicability of these models to industry. A comparison of the industrial validation procedure with the CFD analysis has been realized, focusing on the pros and cons of the two different approaches. A new application solver has been constructed and programmed in order to get the most accurate results with the minimum computational efforts. This solver is based on a completely new and innovative approach to the Navier-Stokes equations for multiphase flow. New model proposed has been used for the evaluation of design for the two slug catchers studied, in order to get a better separation and fluids management.