Effect of polymer drag reducing agent on immiscible oil-water horizontal flow

This paper reports a series of experiments to investigate the characteristics in liquidliquid flow in a horizontal nominal 0.0254 m pipe with and without water soluble polymer drag reducing agent (PDRA). The PDRA was injected at the beginning of the test section at the bottom of the pipe. In these experiments, the focus was on determining the flow pattern and pressure drop with and without adding the PDRA. The pressure gradient was measured for each point on the flow regime map and an attempt was made to correlate change in pressure drop with change of flow pattern. The results showed a significant reduction in pressure gradient due to PDRA especially at high mixture velocity which was accompanied with a clear change in the flow pattern. Phase inversion point in dispersed flow regime occurred at a water fraction range of (0.33-0.35) indicated by its pressure drop peak which disappeared by injecting only 5 ppm (weight basis) of PDRA. Effect of PDRA concentration and molecular weight on flow patterns and pressure drops are presented in this study.