%0 Journal Article
%T Normal Stresses and Interface Displacement: Influence of Viscoelasticity on Enhanced Oil Recovery Efficiency Contraintes normales et d¨¦placement d¡¯interface : influence de la visco¨¦lasticit¨¦ sur l¡¯efficacit¨¦ de la r¨¦cup¨¦ration assist¨¦e
%A Avendano J.
%A Pannacci N.
%A Herzhaft B.
%A Gateau P.
%J Oil & Gas Science and Technology
%D 2013
%I Institut Fran?ais du P¨¦trole
%R 10.2516/ogst/2012063
%X One of chemical Enhanced Oil Recovery (EOR) methods consists in injecting aqueous solutions of polymers into the reservoir in order to improve mobility ratio between the injected fluid and the remaining oil. This ¡°polymer flooding¡± process is usually only characterized with the low shear viscosity of the injected fluid, even if these aqueous solutions are strongly shear thinning and may show high elastic properties evidenced by normal stresses appearance. In order to study the mechanisms at the interface level, we develop simple model experimentations with the goal of quantifying the influence of viscoelastic properties on fluid displacement in a simple geometry. For this purpose, we propose and characterize a model fluid formulation, for which elastic and viscous effects can be tuned systematically. We study then the displacement of a viscous oil by a Newtonian non elastic, a viscoelastic or a purely shear thinning fluid in a two dimensional flow cell. Observing the shape of the interface between aqueous fluids and displaced oil permits to appreciate viscoelasticity effects on the displacement. Using model geometries and controlled rheology fluids, we show that viscoelastic fluids tend to better displace immiscible liquids than Newtonian fluids and that those effects are closely related to the apparitions of normal stresses independently of shear thinning property or variation of interfacial tension as soon as viscous effects govern the flow. Une des m¨¦thodes de r¨¦cup¨¦ration assist¨¦e du p¨¦trole (EOR - Enhanced Oil Recovery) consiste ¨¤ injecter dans les puits des solutions aqueuses de polym¨¨re pour am¨¦liorer le rapport de mobilit¨¦ entre le fluide inject¨¦ et le p¨¦trole qui reste dans le puits. Ce proc¨¦d¨¦ de ¡°polymer flooding¡± est commun¨¦ment caract¨¦ris¨¦ par la seule valeur de la viscosit¨¦ ¨¤ faible gradient de vitesse du fluide inject¨¦, bien que les solutions employ¨¦es pr¨¦sentent une forte rh¨¦ofluidification et ¨¦galement de fortes propri¨¦t¨¦s ¨¦lastiques mises en ¨¦vidence par l¡¯apparition de contraintes normales. Afin d¡¯¨¦tudier les m¨¦canismes mis en jeu au niveau de l¡¯interface, nous avons d¨¦velopp¨¦ des exp¨¦riences mod¨¨les simples pour quantifier l¡¯influence des propri¨¦t¨¦s visco¨¦lastiques dans le cas d¡¯un fluide d¨¦pla ant un autre dans une g¨¦om¨¦trie simple. A cette fin, nous proposons et caract¨¦risons un fluide mod¨¨le avec des composantes visqueuses et ¨¦lastiques ajustables. Nous ¨¦tudions ainsi le d¨¦placement d¡¯une huile visqueuse par un fluide Newtonien non ¨¦lastique, un fluide visco¨¦lastique ou un fluide purement rh¨¦ofluidifiant dans une cellule d¡¯¨¦coulem
%U http://dx.doi.org/10.2516/ogst/2012063