Guar Gum as Flow Improver in Single-PhaseWater and Liquid–Liquid Flows

摘要

In this study, the effectiveness of guar gum as a flow improver in single-phase water as well as in oil–water flows was investigated. Guar gum is one of the hydrocolloidsmostly used as a flow improver because of its unique rheological behaviour. It forms highly viscous shear thinning solutions at very low concentrations. In the oil industry, pressure drop is experienced in the transportation of fluid due to skin friction in the pipeline which translates to high energy cost. The addition of small amount of heavy molecular weight synthetic polymer has been found to enhance flow in pipes. This phenomenon is called drag reduction (DR). However, very few reports exist on the potentials of natural polymers which are more environmentally friendly and cheaper as a DR agent. The experimental rig consists of a horizontal 12- and 20-mm-ID uPVC pipes with oil (ρ = 832 kg/m~3; μ= 3.5 cP at 25°C) and tap water (ρ = 998 kg/m~3; μ = 1.0 cP at 25°C) as test fluids. The molecular weight of guar gum was determined to be 994,035±1.9% g/mol. Results showed that maximum drag reduction of 45% was achieved by the addition of 200 ppm of guar gum to single-phase water flow at Re of 69,000 in the 12-mm-ID pipe. In oil–water flows, maximum DR of 23% was achieved for 0.25 oil fraction and 200 ppm of guar gum. In addition, drag reduction was found to increase with pipe diameter and decrease with increasing oil fraction. DR with guar gum compares better with synthetic polymers of equivalent molecular weight with promise for wider industrial applications.