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.