Analysis on the Transient-State of the Gas-Condensate Pipeline

The mixture energy equation of the pipeline is developed. By introducing the mass transfer between the two phases, the two-fluid model is extended to two phase flow simulation in pipeline. Taking the space limit of the pipe in pipeline multiphase flow into account, the combined continuity equation is established to represent the interaction between phases, and a segregated solution method is promoted and adopted in this study. A numerical method coupled with phase behavior, flow pattern and hydro-thermodynamic is presented through combing mixture energy equation and two-fluid model developed in transient condition, and is used to simulate the transient-state two-phase in gas-condensate pipeline. In discretization, high-resolution scheme is adopted for conquering nonphysical oscillation caused by step distribution of air void fraction on premise of at least second accuracy. Simulation results have a good performance on the fluctuation of the pipeline multiphase flow and on depressing the dispersion and dissipation. Compared with the OLGA (a commercial software), the maximum difference of the liquid phase fraction is 0.075, the pressure is 0.08MPa and the temperature is 0.6°C.