METHODS AND COMPOSITIONS FOR REDUCING THE PERMEABILITIES OF SUBTERRANEAN ZONES.

摘要

Methods and compositions for reducing the permeabilities of subterranean zones are provided. The methods of the invention are basically comprised of introducing an aqueous composition comprised of a chelated organic gelling agent and a copolymer of an ethylenically unsaturated polar monomer and an ethylenically unsaturated ester or a terpolymer or tetrapolymer of an ethylenically unsaturated polar monomer, an ethylenically unsaturated ester and a monomer selected from AMPS(R) and/or N-vinylpyrrolidone into the zone and then allowing the aqueous composition to form a cross-linked gel in the zone.