Experimental Study on High Viscosity Oil/Water Flow in Horizontal and Vertical Pipes

Abstract

Abstract The average crude oil produced around the world becomes heavier every year. High viscosity oil multiphase pipe flows are experienced during the production and transportation of heavy oils at normal temperatures or conventional oil at low temperatures. Heavy oil is normally produced with low GOR but considerable water cut due to cognate or enhance oil recovery reasons. Since high viscosity oil-water two-phase flows were not well understood, an experimental study of high viscosity oil-water flows in horizontal and vertical pipes with a 50.8-mm ID has been conducted to investigate the effect of high oil viscosity on flow pattern, pressure gradient and water holdup. The observations and measurements of flow pattern, pressure gradient and water holdup were obtained over the ranges of oil and water superficial velocities from 0.1 to 1m/s for horizontal and verical upward flows. The pressure was maintained at 2 MPa using compressed Tulsa City natural gas. Non-additive Lubsoil ND 50 was used as test oil and filtered tap water as water phase. Oil viscosities varied from 0.22 to 1.07 Pa·s. The flow patterns and oil-water mixing status were observed through a sapphire window and the images were recorded using high speed and high definition video cameras. The flow patterns were mostly dispersion of oil in water and water layer (DO/W&W) for horizontal flows and core annular flow for vertical flows. Extensive measurements of water holdups and pressure gradients at different superficial velocities, viscosities and inclinations were acquired and analyzed.