Eventos Anais de eventos
COBEM 2019
25th International Congress of Mechanical Engineering
SHEAR HISTORY AS THE MAIN POINT TO DETERMINE THE MECHANICAL BEHAVIOR OF WAXY OILS
Submission Author:
Amanda Legnani , PR
Co-Authors:
Amanda Legnani, Tainan Gabardo, Diogo Elias da Vinha Andrade, Cezar Otaviano Ribeiro Negrao
Presenter: Amanda Legnani
doi://10.26678/ABCM.COBEM2019.COB2019-1409
Abstract
Waxy crude oil is a complex mixture of hydrocarbons that includes paraffins. During production, the oil at high temperature in the reservoir loses heat to the surrounding and the paraffins crystalize. These solid crystals suspended in the material provide a non-Newtonian behavior to the fluid. The shear and thermal histories imposed to the waxy oil affect the crystallization process, the final morphology of the crystals and finally the mechanical behavior of the material at low temperatures. Recent studies have showed that the equilibrium flow curve of waxy oils is a function of the highest shear rate imposed to the material (Mendes et al. 2015, Geri et al. 2017). In the current work, the effect of the shear history in the flow curve of a model waxy oil is revisited by carrying out controlled shear rate experiments in a rotational rheometer. The experiments consisted of imposing different shear rate plateaus to the material during different times. It was observed that the equilibrium depends on a combination of the shear rate and on the time this shear rate is imposed, in other words, the total shear strain imposed to the material is the key point to determine the influence of the shear history on the rheological behavior of waxy oil.
Keywords
Waxy Crude Oil, paraffins, total shear strain, shear rate
