Studies on Drag Reduction in Pipe Flow of Heavy Oil by Using Polymer Additives

Abstract

Some authors have observed that when a minute amount of high molecular weight polymer injected in the pipe flow, a significant amount of drag has been decreased. This phenomenon is known as drag reduction phenomenon. Although, the drag reduction by using polymer additives is quite effective still the design of the experimental set-ups and injection system is more complex. In this study, instead of using synthetic polymers, biopolymers like guar gum and gum Arabic were investigated in the one-phase and two-phase flows. Although some authors were able to produce the drag reduction percentage almost 80% with synthetic polymers using premixed solution. In this study, the biopolymers were tested in the turbulent flow and heterogeneous injection of the polymers was used. With heterogeneous injections using biopolymer additives almost 70% drag reduction was observed. Moreover, guar gum and gum arabic are easily available and quite cost effect than synthetic polymers. These both biopolymers are environment friendly because of non-toxic in nature and easily bio-degradable. The other favorable properties of guar gum and gum arabic are gel and film forming ability, higher viscosity and high ability for chemical modification and cross linking. In the earlier experimentation, the experimental set-up was designed for the injection of the polymer solutions near the boundary layer. By performing some pilot experiments three polymers were selected. One was oil-soluble polymer known as polydimethylsiloxane and the other two polymers were water-soluble polymers i.e. guar gum and gum Arabic. Guar gum is easily soluble in water to produce highly viscous solution, while on the other side gum arabic is also readily soluble in water but do not form too viscous solution like guar gum. However, if allow hydration overnight, the solubility is enhanced. Rheological characterization of the selected polymers was done. The effect of the polymer concentration and the shear rate on viscosity was observed.