Method for inhibiting water permeation in an extraction well of a hydrocarbon fluid from an underground reservoir
A method for inhibiting water permeation in an extraction well of a hydrocarbon fluid from an underground reservoir may include: supplying a water-in-oil emulsion including an oily continuous phase and an aqueous discontinuous phase containing a plurality of particles of at least one hydrogel containing a cationic polymer; and positioning the water-in-oil emulsion in contact with the underground reservoir. A treatment fluid for hydrocarbon fluid extraction wells may contain a water-in-oil emulsion including an oily continuous phase and an aqueous discontinuous phase containing a plurality of particles of at least one hydrogel containing a cationic polymer.
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.
2. The method of claim 1 , wherein the cationic group of the first monomer (1) is a —N + —R 1 R 2 R 3 group,
wherein R 1 , R 2 , and R 3 are independently H or a C 1 -C 4 alkyl group.
3. The method of claim 1 , wherein the first monomer (1) comprises a water-soluble salt of [2-(methacryloyloxy)ethyl] trimethylammonium and/or a water-soluble salt of 2-(acryloyloxy) ethyl trimethyl ammonium.
4. The method of claim 3 , wherein the second monomer (2) comprises poly(ethylene glycol)methyl ether acrylate, poly(ethylene glycol)methyl ether methacrylate, or a mixture thereof.
5. The method of claim 4 , wherein a weight ratio of the poly(ethylene glycol)methyl ether acrylate, poly(ethylene glycol)methyl ether methacrylate, or mixture thereof to the water-soluble salt of [2-(methacryloyloxy)ethyl] trimethylammonium and/or water-soluble salt of 2-(acryloyloxy) ethyl trimethyl ammonium, in polymerized form, is in a range of from 5 to 50%.
6. The method of claim 4 , wherein the second monomer (2) comprises the poly(ethylene glycol)methyl ether acrylate or the poly(ethylene glycol)methyl ether methacrylate, and
wherein the poly(ethylene glycol)methyl ether acrylate or poly(ethylene glycol)methyl ether methacrylate has a molecular weight in a range of from 200 to 10000 Da.
7. The method of claim 1 , wherein the cationic polymer is a cross-linked polymer.
8. The method of claim 1 , wherein the oily continuous phase is present in a ratio with respect to the aqueous discontinuous phase in a range of from 50:50 to 95:5 by weight.
9. The method of claim 1 , wherein the hydrogel particles have an average diameter in a range of from 1 to 1000 μm.
10. The method of claim 1 , wherein the hydrogel particles have an average diameter in a range of from 10 to 500 nm.
11. The method of claim 1 , further comprising:
(a) positioning a first aliquot of an oily fluid in contact with the underground reservoir;
(b) the positioning of the water-in-oil emulsion;
(c) positioning a second aliquot of the oily fluid; and
(d) injecting a displacement fluid for producing the hydrocarbon fluid.
12. The method of claim 1 , wherein the second monomer (2) comprises poly(ethylene glycol)methyl ether acrylate, and wherein the poly(ethylene glycol)methyl ether acrylate has a molecular weight in a range of from 200 to 10000 Da.
13. The method of claim 1 , wherein the second monomer (2) comprises poly(ethylene glycol)methyl ether methacrylate, and wherein the poly(ethylene glycol)methyl ether methacrylate has a molecular weight in a range of from 200 to 10000 Da.
14. The method of claim 1 , wherein the second monomer (2) comprises poly(ethylene glycol)methyl ether acrylate, poly(ethylene glycol)methyl ether methacrylate, or a mixture thereof.