Abstract: The invention concerns modified hydrophobic polyelectrolytes by amide formation of a hydrophilic skeleton by n-alkylamines whereof the alkyl chain comprises 6 to 22 carbon atoms. Preferably, the amide formation is obtained by di-n-dodecylamine. The hydrophilic skeleton is preferably a sodium polyacrylate or polyacrylic acid corresponding to a statistical acrylate-AMPS copolymer. Said polymers can be used for stabilizing direct or invert emulsions likely to be destabilized or inverted by a modification in the degree of salinity of the aqueous phase or a pH modification. The invention is particularly useful for stabilizing oil drilling fluids or the like in particular drilling, fracturation, acidification or completion fluids.

Abstract: The invention concerns a method for preparing anisotropic silica aggregates comprising the following steps: a) contacting at least one polymer with non-aggregated silica particles and/or highly dispersed in an aqueous medium, with a ratio R, polymer weight to silica particle surface, ranging between 0.03 and 2 mg/m; 2; and whereof the electrostatic value of the silica particle surface is not less than the value of the charge of the silica particle surface measured in an aqueous phase without added salts at a pH not less than 7; b) consolidating the aggregates obtained at step a) either by heat treatment, or by precipitation of a mineral compound.

Abstract: Water-based fluids that can viscosify under shear or can produce a gel or form a gel under shear are obtained by dissolving polymers in an aqueous phase. These polymers comprise three types of functional groups: non-ionic functional groups that are hydrosoluble at the temperature under consideration, ionic functional groups, and functional groups that are hydrophobic at the temperature under consideration. These three types of functional groups can be distributed or spread in a random distribution along the polymer chain. A slightly block distribution is acceptable. For applications to oil wells, functional groups are used which exhibit LCST (Lower Critical Solution Temperature) behavior (i.e., a low critical solution temperature) instead of hydrophobic functional groups. At temperatures below the LCST, the functional groups are hydrophobic.

Abstract: The invention concerns modified hydrophobic polyelectrolytes by amide formation of a hydrophilic skeleton by n-alkylamines whereof the alkyl chain comprises 6 to 22 carbon atoms. Preferably, the amide formation is obtained by di-n-dodecylamine. The hydrophilic skeleton is preferably a sodium polyacrylate or polyacrylic acid corresponding to a statistical acrylate-AMPS copolymer. Said polymers can be used for stabilizing direct or invert emulsions likely to be destabilized or inverted by a modification in the degree of salinity of the aqueous phase or a pH modification. The invention is particularly useful for stabilizing oil drilling fluids or the like in particular drilling, fracturation, acidification or completion fluids.

Abstract: The invention concerns modified hydrophobic polyelectrolytes by amide formation of a hydrophilic skeleton by n-alkylamines whereof the alkyl chain comprises 6 to 22 carbon atoms. Preferably, the amide formation is obtained by di-n-dodecylamine. The hydrophilic skeleton is preferably a sodium polyacrylate or polyacrylic acid corresponding to a statistical acrylate-AMPS copolymer. Said polymers can be used for stabilising direct or invert emulsions likely to be destabilised or inverted by a modification in the degree of salinity of the aqueous phase or a pH modification. The invention is particularly useful for stabilising oil drilling fluids or the like in particular drilling, fracturation, acidification or completion fluids.