Abstract: A method for limiting and/or preventing the migration of fines in a geological formation, in particular a subterranean formation, the method including bringing the formation into contact with one or more copolymers including at most 40 mol % of repeating units derived from a cationic monomer.

Abstract: The present invention relates to a method for enhanced oil recovery by flushing an underground formation, comprising the injection into the underground formation of an aqueous composition comprising microgels having at least one crosslinked polymer, characterized in that the polymer is crosslinked with at least one crosslinking agent capable of being degraded under the temperature conditions of the underground formation, and a content of crosslinking agent between 1 and 90 ppm per mole with respect to the total number of moles of monomer constituting the polymer.

Abstract: The present invention relates to a method for enhanced oil recovery by flushing an underground formation, comprising the injection into the underground formation of an aqueous composition comprising microgels having at least one crosslinked polymer, characterized in that the polymer is crosslinked with at least one crosslinking agent capable of being degraded under the temperature conditions of the underground formation, and a content of crosslinking agent between 1 and 90 ppm per mole with respect to the total number of moles of monomer constituting the polymer.

Abstract: A process for the treatment of a rock formation or cavity, including the step of injecting, into the rock formation or cavity, a water solution of a water-soluble thermo-thickening polymer, the thermo-thickening polymer being able to form a gel at a threshold temperature (Tg), an inner temperature (Tint) of the rock formation or cavity being equal or superior to the threshold temperature (Tg), the process being characterized in that the thermo-thickening polymer is a cellulose chain, partially etherified with C1-C6 alkyl or hydroxyalkyl groups, or a polyacrylamide-based copolymer including N-isopropylacrylamide and/or N-vinylpyrrolidone groups. Such a process is advantageous for water shutoff in gas- or oilfields, or to solve to water channelling problems between injection wells and production wells.

Abstract: A process for the treatment of a rock formation or cavity, including the step of injecting, into the rock formation or cavity, a water solution of a water-soluble thermo-thickening polymer, the thermo-thickening polymer being able to form a gel at a threshold temperature (Tg), an inner temperature (Tint) of the rock formation or cavity being equal or superior to the threshold temperature (Tg), the process being characterized in that the thermo-thickening polymer is a cellulose chain, partially etherified with C1-C6 alkyl or hydroxyalkyl groups, or a polyacrylamide-based copolymer including N-isopropylacrylamide and/or N-vinylpyrrolidone groups. Such a process is advantageous for water shutoff in gas- or oilfields, or to solve to water channelling problems between injection wells and production wells.

Abstract: A method for the treatment of rock formations which may or may not be underground and, more particularly, of oil or gas production wells, water-injection wells intended to flood hydrocarbon (oil or gas) reservoirs or gas mines or gas storage wells includes a step of injecting, into the rock formation or well, a microgel obtained by dilution in water of a self-invertible inverse latex or of a self-invertible inverse microlatex of a crosslinked polyelectrolyte, obtained by copolymerization, in the presence of a crosslinking agent of partially- or totally-salified free 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid, with at least one cationic monomer chosen from: 2,N,N,N-tetramethyl-2-[(1-oxo-2-propenyl)amino]propanammonium chloride; N,N,N-trimethyl-3-[(1-oxo-2-propenyl)amino]propanammonium chloride; diallyldimethylammonium chloride; N,N,N-trimethyl-2-[(1-oxo-2-propenyl)]ethanammonium chloride; N,N,N-trimethyl-2-[(1-oxo-2-methyl-2-propenyl)]ethanammonium chloride; or N,N,N-trimethyl-3-[(1-oxo-2-meth

Abstract: The present invention relates to a method of treating porous and permeable underground formations or cavities of reservoir rock or sand foundation type. The method consists in injecting a liquid composition comprising microgels into the formations in order to reduce the production of water, gas or sands, and/or for zone abandonment.

Abstract: A method for the treatment of rock formations which may or may not be underground and, more particularly, of oil or gas production wells, water-injection wells intended to flood hydrocarbon (oil or gas) reservoirs or gas mines or gas storage wells includes a step of injecting, into the rock formation or well, a microgel obtained by dilution in water of a self-invertible inverse latex or of a self-invertible inverse microlatex of a crosslinked polyelectrolyte, obtained by copolymerization, in the presence of a crosslinking agent of partially- or totally-salified free 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid, with at least one cationic monomer chosen from: 2,N,N,N-tetramethyl-2-[(1-oxo-2-propenyl)amino]propanammonium chloride; N,N,N-trimethyl-3-[(1-oxo-2-propenyl)amino]propanammonium chloride; diallyldimethylammonium chloride; N,N,N-trimethyl-2-[(1-oxo-2-propenyl)]ethanammonium chloride; N,N,N-trimethyl-2-[(1-oxo-2-methyl-2-propenyl)]ethanammonium chloride; or N,N,N-trimethyl-3-[(1-oxo-2-meth

Abstract: The present invention relates to a method of treating porous and permeable underground formations or cavities of reservoir rock or sand foundation type. The method consists in injecting a liquid composition comprising microgels into the formations in order to reduce the production of water, gas or sands, and/or for zone abandonment.

Abstract: For selectively reducing permeability to water in an underground formation producing oil and/or gas, injecting into the formation a composition comprising water, at least one water soluble aldehyde compound at a concentration (by weight) of 180 to 20,000 ppm and at least one non-ionic polysaccharide at a concentration (by weight) of 200 to 5000 ppm, the concentration of aldehyde compound being higher than that of polysaccharide. The composition may be used in the water injection well or the hydrocarbon producing well and may assist in the recovery of hydrocarbons.

Abstract: This process comprises injecting a non-hydrolyzed acrylamide polymer or copolymer into the producing formation and producing hydrolysis thereof in situ by subsequent injection of an alkali metal basic compound. It is then possible to restart the well in oil or gas production.

Abstract: The invention relates to a process for reducing or completely stopping a water inflow from a formation towards a producing well.The process according to the invention, using the injection of an aqueous dispersion of hydrosoluble polysaccharide in this producing well, blocks the water inflow without however decreasing the oil and gas flow towards this well.This process is particularly of high interest when the produced water is hot, e.g. at a temperature from 70.degree. to 130.degree. C., and/or salted, e.g. of a salt content of at least 30 g/l.This process is used for oil and/or gas production.