The present invention provides a well treatment fluid containing water, a amine-based polymer, and an oxidized polysaccharide-based polymer. The oxidized polysaccharide-based polymer is able to crosslink with the amine-based polymer and produce a gel having a viscosity of greater than about 20 cp, measured at a pH of about 4 to about 7 and at STP. The present invention also provides a method of treating a subterranean formation penetrated by a wellbore comprising the steps of: (a) forming the well treatment fluid, and (b) contacting the subterranean formation with the fluid.