Method for modifying the water permeability of a subterranean formation

1. A method for modifying water permeability of a subterranean formation, comprising at least the following steps:

preparing an injection fluid from a dispersion of a hydrophilic phase in a lipophilic phase, with water or brine, the dispersion comprising:

a hydrophilic phase comprising at least one cross-linked (co)polymer PR,

a lipophilic phase,

at least one interface polymer composed of at least one monomer of formula (I):

in which,

R1, R2, R3 are independently selected from the group consisting of a hydrogen atom, a methyl group and Z—X,

Z is selected from the group consisting of C(═O)—O; C(═O)—NH; O—C(═O); NH—C(═O)—NH; NH—C(═O)—O; and a saturated or unsaturated, substituted or unsubstituted carbon chain having from 1 to 20 carbon atoms which may have one or more heteroatoms selected from nitrogen and oxygen,

X is a group chosen from alkanolamides, sorbitan esters, ethoxylated sorbitan esters, glyceryl esters, and polyglycosides; and comprising a saturated or unsaturated, linear, branched or cyclic, optionally aromatic, hydrocarbon chain,

injecting the injection fluid into the subterranean formation, said cross-linked (co)polymer PR forming a hydrogel in the presence of water.

2. The method according to claim 1 , wherein the (co)polymer PR or NR is obtained from at least one non-ionic monomer and/or at least one anionic monomer and/or at least one cationic monomer and/or at least one zwitterionic monomer.

3. The method according to claim 2 , wherein the non-ionic monomer is selected from the group consisting of acrylamide, methacrylamide, N-isopropylacrylamide, N,N-dimethylacrylamide, N-methylolacrylamide, N-vinylformamide, N-vinylacetamide, N-vinylpyridine, N-vinylpyrrolidone, acryloyl morpholine, glycidyl methacrylate, glyceryl methacrylate and diacetone acrylamide.

4. The method according to claim 2 , wherein the anionic monomer is chosen from the group consisting of salts of 3-sulphopropyl methacrylate, and unsalified, partially or totally salified monomers chosen from acrylic acid, methacrylic acid, itaconic acid, maleic acid, acrylamido tertiary butyl sulphonic acid, vinylsulphonic acid, and vinylphosphonic acid.

5. The method according to claim 2 , wherein the monomer of formula (I) is selected from sorbitan monooleate (meth)acrylate, 2-hydroxypropyl (meth)acrylate of diethanolamide monooleate or sorbitan monooleate glyceryl (meth)acrylate.

6. The method according to claim 1 , wherein the interface polymer comprises, in addition to the monomer of formula (I), at least one non-ionic monomer and/or at least one anionic monomer and/or at least one cationic monomer.

7. The method according to claim 1 , wherein the monomer of formula (I) has the following formula:

in which,

R1, R2, R3, independently, are a hydrogen atom or a methyl group,

Z is selected from the group consisting of CH 2 , C(═O)—O, C(═O)—NH, and —(C═O)—O—CH 2 —CH(OH)—CH 2 ,

X is a group chosen from alkanolamides and sorbitan esters, and comprising a saturated or unsaturated, linear, branched or cyclic, optionally aromatic, hydrocarbon chain.

8. The method according to claim 1 , wherein the monomer of formula (I) is selected from sorbitan monooleate (meth)acrylate, 2-hydroxypropyl (meth)acrylate of diethanolamide monooleate or sorbitan monooleate glyceryl (meth)acrylate.

9. The method according to claim 1 , characterized in that the monomer of formula (I) has the following formula:

10. The method according to claim 9 , wherein the (co)polymer PR or NR is obtained from at least one non-ionic monomer and/or at least one anionic monomer and/or at least one cationic monomer and/or at least one zwitterionic monomer, and wherein:

the non-ionic monomer is selected from the group consisting of acrylamide, methacrylamide, N-isopropylacrylamide, N,N-dimethylacrylamide, N-methylol acrylamide, N-vinylformamide, N-vinylacetamide, N-vinylpyridine, N-vinylpyrrolidone, acryloyl morpholine, glycidyl methacrylate, glyceryl methacrylate and diacetone acrylamide; and

the anionic monomer is chosen from the group consisting of salts of 3-sulphopropyl methacrylate, and unsalified, partially or totally salified monomers chosen from acrylic acid, methacrylic acid, itaconic acid, maleic acid, acrylamido tertiary butyl sulphonic acid, vinylsulphonic acid, and vinylphosphonic acid.

11. The method according to claim 10 , wherein the (co)polymer comprises at least one associative cationic monomer and/or at least one LCST group.

12. The method according to claim 1 , wherein the (co)polymer comprises at least one associative cationic monomer and/or at least one LCST group.

13. The method according to claim 1 , wherein the injection fluid comprises at least one cross-linking agent.