Amphiphilic polymers sequences soluble in highly saline

The present invention relates to the preparation of polymers useful in particular as a rheology agent, and suitable for use in highly concentrated salt media, which comprises a step of free radical polymerization micellar which is brought into contact, in a medium aqueous: - hydrophilic monomers; - hydrophobic monomers in the form of a micellar solution containing micelles comprising the hydrophobic monomers; - a radical polymerization initiator; and - preferably a radical polymerization control agent, wherein said micelles comprise at least one amphoteric surfactant nature. The polymers obtained according to the invention are particularly useful for enhanced oil recovery (EOR).