Patent ID: 11859125
Assignee: ENI S.P.A.
Field: Basic materials chemistry (Chemistry)
Classification: CPC C  E | IPC C  E

Claim 0:
1. A method for inhibiting water permeation in an extraction well of a hydrocarbon fluid from an underground reservoir, the method comprising:
positioning a water-in-oil emulsion in contact with the underground reservoir, the water-in-oil emulsion comprising (i) an oily continuous phase and (ii) an aqueous discontinuous phase comprising a plurality of hydrogel particles comprising a cationic polymer; and
inhibiting water mobility by waiting a sufficient period of shut-in time to allow the water-in-oil emulsion to release the hydrogel polymer particles once they come into contact with reservoir water,
wherein the cationic polymer comprises, in polymerized form, (1) a first monomer comprising a cationic group and (2) a second monomer comprising an ethylenic unsaturation and a polyoxyethylene chain, and
wherein the cationic polymer comprises no anionic unit.