Compositions and methods for selective modification of subterranean formation permeability

A method for controlling water by treating a subterranean formation in a production well, comprising

• introducing a water control treatment fluid into said formation through said production well, said water control treatment fluid comprising a copolymer and an aqueous base fluid;
• wherein said copolymer comprises a hydrophilic monomeric unit, a first anchoring monomeric unit;
• and a filler monomeric unit;
• wherein said hydrophilic monomeric unit is based on acrylamidomethylpropanesulfonic acid, wherein said first anchoring monomeric unit is based on N-vinylformamide, and wherein said filler monomeric unit is based on acrylamide, methylacrylamide or a mixture thereof;
• wherein said copolymer comprises an effective amount of said first anchoring monomeric unit so that when said copolymer is present in an aqueous fluid in an amount of about 2000 ppm it is capable of imparting a resistance factor for water of greater than about 10 and a resistance factor for oil of less than about 2 as measured across a Berea core of about 2.5 cm diameter by about 4 cm long and having a permeability to nitrogen of about 1000 md, each of said water and oil resistance factors being measured at a flow rate of about 0.5 ml/min across said Berea core;
• and
• wherein said water control treatment fluid is introduced at flow rates below a flow rate that would cause pressures to exceed those necessary to fracture said formation.

A method for treating a subterranean formation, comprising:

• introducing a water control treatment fluid into said formation, said water control treatment fluid comprising a copolymer and an aqueous base fluid;
• wherein said copolymer comprises a hydrophilic monomeric unit, a first anchoring monomeric unit;
• and a filler monomeric unit;
• wherein said hydrophilic monomeric unit is based on acrylamidomethylpropanesulfonic acid, wherein said first anchoring monomeric unit is based on N-vinylformamide, and wherein said filler monomeric unit is based on acrylamide, methylacrylamide, or a mixture thereof;
• and
• wherein said water control treatment fluid further comprises a mutual solvent.

A method for treating a subterranean formation, comprising:

• introducing a water control treatment fluid into said formation, said water control treatment fluid comprising a copolymer and an aqueous base fluid;
• wherein said copolymer comprises a hydrophilic monomeric unit and a first anchoring monomeric unit;
• wherein said first anchoring monomeric unit is based on at least one of N-vinylformamide, N,N-diallylacetamide, or a mixture thereof;
• and
• wherein said water control treatment fluid is introduced into said subterranean formation prior to introducing a stimulation fluid into said subterranean formation.

A method for treating a subterranean formation, comprising:

• introducing a water control treatment fluid into said formation, said water control treatment fluid comprising a copolymer and an aqueous base fluid;
• wherein said copolymer comprises a hydrophilic monomeric unit, a first anchoring monomeric unit;
• and a filler monomeric unit;
• wherein said hydrophilic monomeric unit is based on acrylamidomethylpropanesulfonic acid, wherein said first anchoring monomeric unit is based on N-vinylformamide, and wherein said filler monomeric unit is based on acrylamide, methylacrylamide, or a mixture thereof;
• and
• further comprising pre-hydrolyzing said copolymer prior to introducing said treatment fluid into said formation by:
• dissolving said polymer in an aqueous solution;
• adjusting a pH of said treatment fluid to from about 1 to about 3;
• heating said treatment fluid to a temperature of from about 20° C. to about 100° C.;
• and
• neutralizing said treatment fluid to a pH of from about 7 to about 8.5.

A method for treating a subterranean formation, comprising:

• introducing a water control treatment fluid into said formation, said water control treatment fluid comprising a copolymer and an aqueous base fluid;
• wherein said copolymer comprises a hydrophillic monomeric unit and a first anchoring monomeric unit;
• wherein said first anchoring monomeric unit is based on at least one of N-vinylformamide, N,N-diallylacetamide, or a mixture thereof;
• and
• wherein said copolymer further comprises a second anchoring monomeric unit based on at least one of dimethyldiallyl amnonium chloride, ammonium or alkali metal salts of acrylic acid, or a mixture thereof.