Abstract: A treatment fluid may be suitable for a hydrocarbon fluid extraction well. Such a treatment fluid may include a water-in-oil emulsion. The water-in-oil emulsion may include: an oily continuous phase; and an aqueous discontinuous phase comprising water and a plurality of particles comprising a hydrogel comprising a cationic polymer. The cationic polymer may include, in polymerized form, a monomer with one or more cationic groups. The cationic group may be a —N+—R1R2R3 group, wherein R1, R2, and R3, are independently H or a C1 to C4 alkyl group.

Abstract: A method for inhibiting water permeation in an extraction well of a hydrocarbon fluid from an underground reservoir may include: supplying a water-in-oil emulsion including an oily continuous phase and an aqueous discontinuous phase containing a plurality of particles of at least one hydrogel containing a cationic polymer; and positioning the water-in-oil emulsion in contact with the underground reservoir. A treatment fluid for hydrocarbon fluid extraction wells may contain a water-in-oil emulsion including an oily continuous phase and an aqueous discontinuous phase containing a plurality of particles of at least one hydrogel containing a cationic polymer.

Abstract: The present invention relates to a composition for inhibiting water permeation in an extraction well of a hydrocarbon oil from an underground reservoir which comprises injecting into said reservoir at least one polymerizable composition comprising: at least one hydrophilic monomer, at least one hydrophilic initiator of radical polymerization with thermal activation (hydrophilic initiator), at least one lipophilic initiator of radical polymerization with thermal activation (lipophilic initiator). The present invention also relates to the polymerizable compositions that can be used in said method.

Abstract: A method for inhibiting water permeation in an extraction well of a hydrocarbon fluid from an underground reservoir containing: supplying a water-in-oil emulsion an oily continuous phase and an aqueous discontinuous phase containing a plurality of particles of at least one hydrogel containing a cationic polymer; and positioning the water-in-oil emulsion in contact with the underground reservoir. The present invention also concerns a treatment fluid for hydrocarbon fluid extraction wells containing the aforementioned water-in-oil emulsion and the related preparation process.

Abstract: The present invention relates to a composition for inhibiting water permeation in an extraction well of a hydrocarbon oil from an underground reservoir which comprises injecting into said reservoir at least one polymerizable composition comprising: at least one hydrophilic monomer, at least one hydrophilic initiator of radical polymerization with thermal activation (hydrophilic initiator), at least one lipophilic initiator of radical polymerization with thermal activation (lipophilic initiator). The present invention also relates to the polymerizable compositions that can be used in said method.

Abstract: The present invention relates to a method for inhibiting water permeation in an extraction well of a hydrocarbon oil from an underground reservoir which comprises injecting into said reservoir at least one polymerizable composition comprising: at least one hydrophilic monomer, -at least one hydrophilic initiator of radical polymerization with thermal activation (hydrophilic initiator), at least one lipophilic initiator of radical polymerization with thermal activation (lipophilic initiator). The present invention also relates to the polymerizable compositions that can be used in said method.

Abstract: The present invention relates to a method for inhibiting water permeation in an extraction well of a hydrocarbon oil from an underground reservoir which comprises injecting into said reservoir at least one polymerizable composition comprising: at least one hydrophilic monomer, —at least one hydrophilic initiator of radical polymerization with thermal activation (hydrophilic initiator), at least one lipophilic initiator of radical polymerization with thermal activation (lipophilic initiator). The present invention also relates to the polymerizable compositions that can be used in said method.

Abstract: Process for the removal of deposits from an oil or gas well, and/or from surface structures, and/or from the equipment connected therewith, and/or from hydrocarbon-bearing formations, comprising:—injecting at least one oil-in-water nanoemulsion into said oil or gas well, and/or surface structures, and/or equipment connected therewith, and/or hydrocarbon bearing formations; leaving said nanoemulsion in said oil or gas well, and/or surface structures, and/or equipment connected therewith, and/or hydrocarbon bearing formations, for a predetermined time.

Abstract: A water-based fluid, containing: a non-ionic surfactant, which is stable in a temperature range from 10 to 90° C. and soluble in water; and a salt, wherein the non-ionic surfactant contains an alkyl polyglucoside selected from the group consisting of a C8 alkyl polyglucoside, a C10 alkyl polyglucoside, and mixtures thereof, and the salt is present, and is present in an amount up to 60%. In addition, a process for preventing the formation of a W/O inverse emulsion or resolving a W/O inverse emulsion that has already formed in an oil well in which an oil-based mud has been employed by injecting the water-based fluid into the oil well.

Abstract: Process for the removal of deposits from an oil or gas well, and/or from surface structures, and/or from the equipment connected therewith, and/or from hydrocarbon-bearing formations, comprising: —injecting at least one oil-in-water nanoemulsion into said oil or gas well, and/or surface structures, and/or equipment connected therewith, and/or hydrocarbon bearing formations; leaving said nanoemulsion in said oil or gas well, and/or surface structures, and/or equipment connected therewith, and/or hydrocarbon bearing formations, for a predetermined time.

Abstract: Process for the recovery of oils from a solid matrix comprising: subjecting said solid matrix to extraction by mixing with an oil-in-water nanoemulsion, obtaining a solid- liquid mixture; subjecting said solid- liquid mixture to separation, obtaining a liquid phase comprising said oils and a solid phase comprising said solid matrix; recovering said oils from said liquid phase. Said process is particularly advantageous for the recovery of oils from water wet oil sands (or water wet tar sands), oil wet sands (or oil wet tar sands), oil rocks, oil shales, more specifically from oil wet sands (or oil wet tar sands).

Abstract: The invention relates to a water-based fluid for applications in the oil field, comprising non-ionic surfactants, stable at temperatures ranging from 10 to 90° C., having an HLB ranging from 8 to 20 and soluble in water, with a saline content ranging from 0 to 60% by weight, and possibly salts. The fluid can be conveniently used as completion fluid for preventing the formation of inverse W/O emulsions or as a remedial fluid for resolving emulsions already formed in oil wells in which oil-based mud has been used.

Abstract: An aqueous gellable composition capable of producing gels resistant to syneresis in the presence of divalent ions, contains:a water-soluble acrylamide polymer or copolymer,a crosslinking agent formed by a water-soluble aldehyde, or a water-soluble aldehyde and a water-soluble phenol,a water-soluble anti-syneresis agent selected from: organic carboxy acids, organic hydroxy acids and aminoacids, or among aminophosphonic acids and their alkali-metal or ammonium salts.When malonic acid is used, a delay in aqueous composition gelation is additionally obtained.

Abstract: An aqueous gellable composition having a delayed gelling time presettable within wide time and temperature ranges, contains a water-soluble organic polymer crosslinkable with chrome ion and a crosslinking/retardant system definable by the formula:Cr(L).sub.m.nL'wherein:Cr is a trivalent chrome ion;L is an organic ligand consisting of a monocarboxylate or dicarboxylate ion, optionally bearing one or more amino or hydroxy functional group(s), in form complexed with chrome ion;L' is an organic ligand consisting of a monocarboxy or dicarboxy acid, optionally bearing one or more amino or hydroxy functional group(s), in form not complexed with chrome ion;m has a value comprised within the range of from 1 to 3, depending on the nature of the ligand L;n has a value comprised within the range of from 0.5 to 100;with the proviso that in the crosslinking/retardant system, the ligand L is different from the ligand L'.

Abstract: An aqueous gellable composition having a delayed gelling time is disclosed, which contains a water-soluble polymer crosslinkable with Cr.sup.3+ and a crosslinking/retardant system containing a Cr.sup.3+ ion and a salicylic acid ligand, wherein said ligand can be in free form, or in the form of a complex with Cr.sup.3+, or partially in free form and partially in complexed form.Such a composition is useful for modifying the permeability in petroleum reservoirs, within a wide range of temperatures, of from about 60.degree. C. to 120.degree. C., or higher temperatures.