Effect of pipeline inclination on multiphase flow

Production and transport of petroleum fluids involve multiphase flow in pipelines. Handling of these fluids requires knowledge of flow behavior. Experimental works have been a key contributor towards understanding the flow behavior in multiphase pipelines. Many experimental works covered two-phase flow and horizontal and vertical pipelines, while there are scarce works on inclined pipelines and three-phase flow. This paper aims to present an experimental study on the analysis of the effect of inclination on flow pattern behavior. The flow pattern is important information during the handling of multiphase flow since it guides the prediction of other operating parameters. In this study, air, water, and oil (Exxol D80) were used in a 60 mm internal diameter inclined pipe with 6 m in length. Flow patterns were recognized using a high-speed camera and conductance probes. Results show that inclination has a significant effect on flow pattern distribution in multiphase flow pipelines. Intermittent flow, especially slug flow, dominates a wide range of operating flow rates. Critical superficial gas velocity, which represents gas superficial velocity for appealing of liquid loading is significantly affected by inclination. The maximum value was found at 45° inclination from horizontal. Water cut had a low influence on loading point values. This might be caused by the type of oil that was used (light oil with properties close to that of water). This work gives a unique detailed description of the effect of inclination on flow pattern behavior and the loading point of three- phase flow.