Patent ID: 8322421

Claim:
A method for blocking the permeability of a portion of a subterranean formation penetrated by a wellbore, the method comprising the steps of: (a) selecting the portion of the subterranean formation to be treated; (b) selecting estimated treatment conditions, wherein the estimated treatment conditions comprise temperature over a treatment time; (c) forming a treatment fluid that is a crosslinkable polymer composition comprising: (i) a water-soluble polymer, wherein the water-soluble polymer comprises a polymer of at least one non-acidic ethylenically unsaturated polar monomer; (ii) an organic crosslinker comprising amine groups, wherein the organic crosslinker is capable of crosslinking the water-soluble polymer; (iii) a Lewis acid selected from the group consisting of boron trifluoride, sulfur trioxide, sulfur dioxide, antimony pentachloride, aluminum hydroxide acetate, aluminum chloride, and aluminum bromide, aluminum (III) sulfate, potassium aluminum (III) sulfate belonging to the general class of chemicals known as alums, tin (IV) tetrachloride, tin (II) chloride, and any combination thereof; and (iv) water; (d) selecting the water-soluble polymer, the crosslinker, the Lewis acid, and the water, and the proportions thereof, such that the gelation time of the treatment fluid is at least 1 hour when tested under the estimated treatment conditions; and (e) injecting the treatment fluid through the wellbore into the portion of the subterranean formation.