Factors Influencing Mobility Control By Polymer Solutions

Abstract

Different polymers produce decreased mobility in porous media by different mechanisms, which involve polymer-matrix interactions and solution rheology. Surprisingly, the mobility decreases do not correlate with adsorption of the polymers. Viscoelastic behavior provides a basis for a convenient measure of the mobility control activity of some polymers. Introduction The increasing use of high molecular weight polymers to improve waterflood efficiency has naturally resulted in increased interest on the part of potential users, polymer manufacturers, and universities in the polymer manufacturers, and universities in the mechanisms by which these polymers exert their mobility control effects. This interest has resulted in a number of excellent publications on polymer behavior (Ref. 1 is a recent one). There is a temptation to include in an additional study material that merely supplements or extends information already published. We have tried to resist this temptation and to present new information on the following subjects:the relationship of the rheological properties of different kinds of polymers to their behavior under reservoir flow conditions,the nature of the mobility-reducing interaction between certain polymers and a porous system, anda correlation, with practical implications, between the effects produced by certain polymer solutions in slow flow through porous media polymer solutions in slow flow through porous media and viscoelastic properties of the solutions, which are evident only at high flow rates. Partly tar reasons of convenience, and partly from long-standing habit, we shall use the following nomenclature and definitions to describe some of the effects produced by polymer solutions in porous media:The resistance factor describes the decrease in mobility of a polymer solution in comparison with the flow of the water or brine in which it is prepared. .................(1) The residual resistance factor is used to indicate the decrease in mobility of water that follows a polymer solution relative to water flow before the flow polymer solution relative to water flow before the flow of the polymer solution. ..............(2) We hope that the relationship between these designations and those used by others to describe the same effects will be readily apparent. Experimental Materials and Methods Polymers Polymers The various polymers employed in the experiments are described in Table 1. The abbreviations listed in the table will be used throughout the text to designate the different types of polymers. The experiments to be described were conducted over a period of years, which has caused something of a problem, since the quality of some of the polymers has improved considerably during this time, and polymers has improved considerably during this time, and it was natural to use the best available material in a particular experiment. The result has been a somewhat particular experiment. The result has been a somewhat regrettable lack of correlation from experiment to experiment, although the conclusions drawn from one set of data are generally valid. JPT P. 391