Patent ID: 8623793

Claim:
A method comprising: providing a relative permeability modifier that comprises a hydrophilic polymer backbone with a hydrophobic modification wherein the hydrophilic polymer backbone is selected from the group consisting of: a polyacrylamide; a polyvinylamine; a poly(vinylamine/vinyl alcohol); an alkyl acrylate polymer; cellulose; chitosan; a polyamide; a polyetheramine; a polyethyleneimine; a polyhydroxyetheramine; a polylysine; a polysulfone; a gum; a starch; and a combination thereof; wherein the hydrophobic modification is achieved by reacting the hydrophilic polymer with at least one hydrophobic compound; wherein the hydrophobic compound used for the hydrophobic modification comprises an alkyl chain length of from about 4 to about 22 carbons selected from the group consisting of an alkyl acrylate; an alkyl methacrylate; an alkyl acrylamide; an alkyl methacrylamide; an alkyl dimethylammoniumethyl methacrylate halide and any combination thereof; and incorporating at least one cationic compound onto the hydrophilic polymer backbone to form a hydrophobically and cationically modified relative permeability modifier; wherein the cationic compound comprises at least one cationic compound comprising an alkyl chain length of from about 1 to 3 carbons selected from the group consisting of: an alkyl halide; a sulfone; a sulfate; an organic acid; an organic acid derivative, and a combination thereof.