초록 ▼

Compositions and methods for modifying the permeability of subterranean formations for the purpose of selectively reducing excessive production of aqueous fluids. The compositions include copolymers which may be added to an aqueous fluid to form a water control treatment fluid. The copolymers may in

Compositions and methods for modifying the permeability of subterranean formations for the purpose of selectively reducing excessive production of aqueous fluids. The compositions include copolymers which may be added to an aqueous fluid to form a water control treatment fluid. The copolymers may include copolymers having a hydrophillic monomeric unit, a first anchoring monomeric unit and a filler monomeric unit, with the first anchoring monomeric unit being based on N-vinylformamide. Additional anchoring monomeric units may also optionally be present. The copolymers may be employed in well treatment fluids introduced into production wells or injection wells. The copolymers may also be utilized in conjunction with stimulation treatments and with introduction of other well treatment fluids.

대표청구항 ▼

[ What is claimed is:] [1.]1. 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 ba

[ What is claimed is:] [1.]1. 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 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;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; andwherein 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.