Experimental Investigation on Super High Viscosity Oil-Water Two-Phase Flow in a Horizontal Pipe

The flow patterns and pressure gradient of a two-phase mixture of water/super high viscous oil in a horizontal pipe were experimentally investigated. The mixture containing oil with a viscosity of ۶۷ cP and density of ۰.۸۷۲ g/cm۳, and pure water flows through an acrylic pipe with a length of ۶m and a diameter of ۲۰ mm. Superficial velocities of water and oil were in the range between ۰.۱۸–۱.۲ m/s and ۰.۱۸–۰.۹۵ m/s, respectively. Six flow patterns were identified. The stratified flow became visible at low velocities of oil (<۰.۴۲ m/s) and water (<۰.۲۶ m/s) and bubbly flow patterns happened at low superficial oil velocities (Uso = ۰.۱۸–۰.۲۲ m/s). The dispersion of oil in water (DO/W) occurred at high superficial water velocity (Usw =۰.۷۹ – ۱.۲ m/s) at low or moderate superficial oil velocities (Uso = ۰.۱۸ –۰.۵۳ m/s). Dispersion of water in oil (DW/O) appeared from superficial oil velocity of higher than ۰.۶۹ m/s. The effect of oil viscosity on flow structure was assessed by comparing the present work with the available data and this revealed that the extent of dual continuous patterns reported by other systems containing low viscosity oil is ۵% higher than the results of the present study. The effect of oil viscosity on the pressure gradient was also investigated. The pressure gradient values obtained in this study were ۸۰% greater than other studies at similar superficial oil and water velocities. The experimental pressure gradient was also compared with the values predicted by the Al-Wahaibi correlation and two-fluid model. The Al-Wahaibi correlation agreed reasonably with the experimental results, with an average absolute error of less than ۹%, while the error of the two-fluid model was ۳۰%.  Based on the results, a clear overview of the flow patterns and pressure drop with detailed information was presented.

کلیدواژه ها:

Oil-water flow ، Flow pattern map ، pressure gradient ، Super high viscous oil