Prediction of Wax Deposition in Shale Oil Multiphase Pipelines

Abstract

To tackle flow safety challenges arising from paraffin deposition in low-temperature shale oil multiphase conveying systems, this study establishes a multi-physics coupled model for predicting wax layer growth. The proposed modeling framework integrates a steady-state two-fluid model with thermodynamic equilibrium equations and a kinetics mechanism describing paraffin deposition. This mechanism explicitly accounts for molecular diffusion effects, deposit layer porosity, and shear stripping phenomena. The resultant integrated model facilitates comprehensive prediction of flow regimes, temperature profiles, pressure gradients, and wax layer thickness distribution within multiphase pipelines. Validation against experimental measurements and OLGA simulation results confirms the model's accuracy. Furthermore, the influence of operating temperature and fluid flow rate on the required pigging cycles is investigated. This model provides a robust theoretical foundation for ensuring the safe operation of multiphase pipelines transporting waxy shale oils.