Phase Behavior and Flowing State of Water-Containing Live Crude Oil in Transportation Pipelines

To address the challenges and risks associated with the declining crude yield, an optimization project for the surface production facilities at ZY Oilfield is underway. Upon the completion of this project, the oilfield's export pipelines will transport water-containing live crude oil. To ensure pipeline transportation safety, it is essential to clarify the phase behaviors and flow state of water-containing live oil. For this purpose, the VLLE characteristics of water-containing live oil were analyzed with Aspen HYSYS V12 software and validated through PVT tests. Additionally, the pressure variations in multiphase flow pipelines under different operating conditions were calculated using the Beggs and Brill-Moody-Eaton method with Pipephase 9.6 software. The results indicated that the bubble point pressure and vapor fraction of water-containing live oil were higher than those of dehydrated dead crude within the operating temperature range. Liquid-gas flow was likely to occur in the presence of low soil temperatures, low oil output, low outlet pressure, high outlet temperatures, or small water fractions, particularly at the pipeline ends. Moreover, the optimized technological processes for stations and pipeline operations were proposed. The findings offer a new approach for the safe transportation of low-output live oil and provide valuable insights for optimizing surface production in aging oilfields.