Abstract: Methods of treating a subterranean formation penetrated by a wellbore include providing environmental water, admixing a viscosifying amount of a polymer and at least one divalent cation with the environmental water to form an admixture, and pumping the admixture through the wellbore at a rate and pressure sufficient to treat the subterranean formation. The viscosity of the admixture increases after the at least one divalent cation, the viscosifying amount of polymer and the environmental water are admixed. Such viscosity increase may be at least about 5% over at least a 10 minute period after the admixture is prepared. The divalent cation(s) may be selected from the group consisting of barium, calcium, copper(II), iron(II), magnesium, manganese(II), strontium, tin(II), zinc, and mixtures thereof. Further, the divalent cation(s) may be provided in the form of a salt with one or more anions selected from acetate, bicarbonate, nitrate, chloride, bromide, iodide, sulfate ion, and mixtures thereof.

Abstract: Methods of treating a subterranean formation penetrated by a wellbore include providing environmental water, admixing a viscosifying amount of a polymer and at least one divalent cation with the environmental water to form an admixture, and pumping the admixture through the wellbore at a rate and pressure sufficient to treat the subterranean formation. The viscosity of the admixture increases after the at least one divalent cation, the viscosifying amount of polymer and the environmental water are admixed. Such viscosity increase may be at least about 5% over at least a 10 minute period after the admixture is prepared. The divalent cation(s) may be selected from the group consisting of barium, calcium, copper(II), iron(II), magnesium, manganese(II), strontium, tin(II), zinc, and mixtures thereof. Further, the divalent cation(s) may be provided in the form of a salt with one or more anions selected from acetate, bicarbonate, nitrate, chloride, bromide, iodide, sulfate ion, and mixtures thereof.