Method for treating a subterranean formation

A method of treating a subterranean formation to increase permeability comprising injecting into the formation matrix an amount of an aqueous mixture, sufficient to increase the permeability of the formation, the aqueous mixture comprising an aqueous liquid containing an effective amount of aminopolycarboxylic anionic species selected from EDTA anion, DTPA anion, and mixtures thereof, and cationic species selected from potassium ion, lithium ion, ammonium ion, and mixtures thereof, in a ratio of said cationic species to said aminopolycarboxylic anionic species of at least 1.