| abstract |
This invention provides novel aqueous fluid compositions which comprise a synergistic mixture of two classes of water dispersible or soluble polymers, i.e. (1) synthetic polymeric viscosifier and (2) polycationic organic polymer. These compositions are uniquely adapted for use in enhanced oil recovery. Addition of the polycationic organic polymer reduces the solution viscosity, increases the injectivity of the aqueous solution into low permeability formations. This reaction also reduces the shear degradation of the polymers during pumping, injection through the perforations, and during the period of relatively rapid fluid movement as the solution moves through an earthen or subterranean formation in the important zone within about a ten foot radius around the well bore. Once in an earthen formation, the polycationic organic polymer is rapidly adsorbed from the solution resulting in an increase in solution viscosity and improving the mobility ratio and also resulting in enhanced and/or increased oil recovery. |