Enhancing Multiphase Flow Computational Performance: A Robust Approach Incorporating Phase Transition Modeling and Dynamic Simulation

Abstract In this study, we enhance the stability of flow prediction in multiphase pipelines by integrating modified source term calculations into the widely used SIMPLE (Semi-Implicit Method for Pressure-Linked Equations) algorithm. We address the challenges faced by traditional two-fluid models, particularly in accurately representing physical processes during operational disruptions such as terrain changes. By incorporating corrective measures into the two-fluid equations, including the continuity equation and momentum conservation equation, we refine the accuracy of flow predictions and mitigate disparities between simulated and actual flow behaviors. Furthermore, we systematically examine and investigate the flow behaviors of multiphase pipelines by amalgamating with the classical two-fluid model. Drawing from practical flow conditions and the foundational principles of conservation laws, we formulate a more universally applicable and theoretically robust mechanistic model. Our approach also involves proposing an innovative method for handling the inter-phase exchange term within the mass conservation equation. The Multiphase Flow Calculation Program (MFCP) is developed as a result of these efforts, enabling comprehensive computational simulations. Through comparative analysis with a commercial multiphase flow software simulator, we validate the computational results, demonstrating computational errors remaining under the 10% threshold. These findings affirm the efficacy of the enhanced SIMPLE algorithm and the theoretical advancements introduced through modified source term calculations and mechanistic modeling. Our study not only contributes to the progression of multiphase flow simulation techniques within the offshore oil and gas industry but also addresses the challenges posed by the rigorous marine environment. By fortifying the stability of flow prediction algorithms and enhancing the efficiency and safety of offshore oil and gas transportation systems, our research facilitates better decision-making in pipeline design, operation, and maintenance. Ultimately, this work underscores the importance of integrating theoretical advancements with practical considerations to advance the understanding and management of multiphase flow dynamics in complex offshore environments.