The effect of polyethylene butene (PEB) and xylene on the shear stress of Niger delta crude oil

Abstract

Crude oil production and transportation is plagued by several flow assurance issues especially in offshore environment with prevailing low temperature. One of the flow assurance challenges is the deposition of paraffin wax which usually changes the crude oil flow from Newtonian fluid flow to non- Newtonian fluid flow with increased viscosity. This increased viscosity can impede flow causing the installation of high horsepower pumps for fluid flow. In severe cases, paraffin wax has plugged the pipes and caused production disruption. It is therefore imperative to manage paraffin disposition in crude samples containing paraffin compounds (C18+). This research discusses the use of varying concentrations of Polyethylene Butene (PEB) in managing wax precipitation at various temperatures (10 °C to 35 °C) at a constant shear rate of 511(s-1). The reduction in crude oil temperature increased the shear stress in all experiments conducted. It was discovered that the increasing concentration of PEB from 500ppm to 5000ppm had a sinusoidal effect on reducing the shear stress. 500ppm of PEB effected a 19% reduction in shear stress, while 5000ppm effected a 35% reduction in shear stress. It is important for the engineer to make the choice of inhibitor concentration based on the degree of shear stress reduction required to optimize inhibitor usage.