Determination of Interfacial Tension of Immiscible Two-Phase, Oil-Water System Subjected to Polymeric Drag additives

In this paper, the determination of interfacial tension of immiscible two-phase oil-water system subjected to polymeric drag additives was investigated. Polymeric drag reducing additives (PDRA) have been discovered in the late 1940s, where its first large-scale commercial utilization was implemented in the Trans-Alaskan Pipeline System (TAPS) three decades after its discovery by Toms. The ability of polymer solution to modify the viscosity of the flowing medium translates into its assistance of altering the flow properties during the transportation of fluids. During the process, PDRA promoted the bubbly and dispersed flow into stratified regime, where oil-water is separated via a pronounced interfacial boundary. In this condition, the nature of the interfacial tension is unknown due to the changes caused by the dilution of PDRA into the flowing medium. This research presents the study on the rheological properties of the partially hydrolysed polyacrylamide (PHPA) solution that acted as PDRA. The experimental work consists of viscometry and the pendant drop analysis. Three different concentration; 10 ppm, 50 ppm and 70 ppm from a 1000 ppm master solution of PHPA were tested at elevated temperature to study its rheological properties as well as the interfacial tension of the oil-water phase. From the results, it is clear that higher concentration of PHPA leads to higher viscosity. All solutions that were investigated in this study exhibited “shear thinning”, and is proven as the n value calculated is less than 1. From the results, the PHPA solutions investigated behaved in a non-Newtonian manner that abide the Power Law. The addition of all the PHPA solution had decreased the interfacial tension of the oil-water system