Effect of the down-slope on the structure and the pressure loss of an oil-water stream

• Published in: International journal of multiphase flow 2023-08, Vol.165, p.104483, Article 104483
• Main Authors: Franchi, Riccardo Attilio, Carraretto, Igor Matteo, Chiarenza, Gregorio, Sotgia, Giorgio, Colombo, Luigi Pietro Maria
• Format: Article
• Language: English
• Subjects: Core-annular flow; Heavy oil; Holdup; Inclined flow; Pressure drop
• ISSN: 0301-9322
• DOI: 10.1016/j.ijmultiphaseflow.2023.104483

The methodology and the results of an experimental campaign aimed at characterizing a two-phase flow of an oil-water-mixture in downward inclined pipes are here described. The goal was to assess the effects of the downslope on an oil-water stream in terms of flow patterns, pressure gradients and phase holdup inside a 40 mm I.D. pipe. The experiments ranged within (0.56−1.06ms) and (0.66−1.33ms) oil and water superficial velocities, respectively. The transition from annular to stratified-wavy flow pattern was analyzed and showed to occur at lower oil velocities with respect to the horizontal configuration. The frictional pressure gradients were measured, the results compared to mechanistic and empirical models showed to be in good agreement. The phase holdups were measured by quick-closing valves and compared to horizontal configuration results and literature models. Eventually, the drift-flux model was implemented confirming its applicability and a relationship for the of oil holdup was derived. •Two-phase liquid-liquid flow characterization in inclined pipeline.•Transition from annular to stratified-wavy flow in inclined pipe.•Experimental pressure drop and void fraction comparison with 1D two-phase models.