Some Mechanistic Features of Flow of Polymers Through Porous Media

Abstract

This paper was prepared for presentation at the 47th Annual Fall Meeting of the Society of Petroleum Engineers held in San Antonio, Tex., Oct. 8–11, 1972. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by who the paper is presented. Publication elsewhere after publication in the JOURNAL paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made. provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines. Abstract An extensive experimental investigation was carried out of the flow of aqueous polymer solutions in porous media, consisting of sandstone cores as porous media, consisting of sandstone cores as well as sand packs, some of the latter being in the form of the quadrant of a five-spot pattern. A total of 14 different polymers were tested in the experiments conducted. The hydrocarbons used consisted of three refined oils, and a crude oil, with the viscosities ranging from 3 to 27 centipoises. in addition to the experimental studies, a theoretical model of a polymer flood was also developed, with a view to determine the effect of permeability variation, oil viscosity and polymer permeability variation, oil viscosity and polymer retention on oil recovery by polymer injection. The conclusions derived of this work, are outlined below: Partially hydrolyzed polyacrylamides are more Partially hydrolyzed polyacrylamides are more flexible in applications to waterflooding than polyethylene oxide, since their behavior can be polyethylene oxide, since their behavior can be conveniently controlled by varying the pH and salt content of the solution. The capillary pressure curve for a porous medium containing adsorbed polymer is appreciably different from the curve for the same rock without the polymer, and should be taken into account in computer simulations. The residual resistance factor (in the context of polymer slug injection) depends more on formation permeability than on the resistance factor measured for the given polymer solution. It was found that the resistance factor could be satisfactorily determined in the presence of residual oil. Computer simulations showed that the generalized criteria concerning the effects of permeability variation, oil viscosity, and polymer retention on oil recovery by polymer injection may be misleading. Introduction The use of polymers in mobility control is a well established process. Several papers have been presented in the literature regarding the behavior of polymer solution in porous media, and their use in secondary recovery. Partially hydrolyzed and polyethylene oxide polymers have been extensively studied since they are the most appropriate for waterflooding.