Mobility control polymers for enhanced oil recovery
View Patent ↗Disclosed herein are water-soluble polymers comprising hydrolyzable cross-linked monomer units, and methods for recovering hydrocarbon fluids from a subterranean formation using the water-soluble polymers.
1. A water-soluble cross-linked polymer comprising about 1 mol % to about 100 mol % acrylamide monomers, and further comprising about 0.1 ppm to about 20000 ppm hydrolyzable cross-linked monomer units based on the weight of the water-soluble polymer, wherein the hydrolyzable cross-linked monomer units are covalently cross-linked and the covalently cross-linked monomer units have the structure of formula (II):
wherein:
each X is selected from the group consisting of O, S and NR b ;
each R b is independently selected from the group consisting of —H, unsubstituted or substituted C 1 -C 24 alkyl, unsubstituted or substituted C 2 -C 24 alkenyl and unsubstituted or substituted C 2 -C 24 alkynyl;
each R is independently selected from the group consisting of —H, unsubstituted or substituted C 1 -C 24 alkyl, unsubstituted or substituted C 2 -C 24 alkenyl and unsubstituted or substituted C 2 -C 24 alkynyl;
Y is selected from a group consisting of a bond and a linker comprising 1 to about 100 member atoms; and
each represents a point of attachment to a first polymer backbone, and each represents a point of attachment to the first polymer backbone or to a second polymer backbone; and wherein the water-soluble polymer further comprises at least one anionic monomer unit derived from a monomer selected from the group consisting of an acrylic acid salt, a methacrylic acid salt, a 2-acrylamido-2-methylpropane sulfonic acid salt and a styrene sulfonic acid salt.
2. The water-soluble polymer of claim 1 , wherein the covalently cross-linked monomer units have the structure of formula (IIa):
wherein:
each R is independently selected from the group consisting of —H and —CH 3 ;
Z is selected from the group consisting of a bond and a C 1 -C 12 alkylenyl group; and
each represents a point of attachment to a first polymer backbone, and each represents a point of attachment to the first polymer backbone or to a second polymer backbone.
3. The water-soluble polymer of claim 2 , wherein the covalently cross-linked monomer units have the structure of formula (IIb):
4. The water-soluble polymer of claim 3 , wherein the water-soluble polymer comprises about 0.1 ppm to about 1000 ppm covalently cross-linked monomer units.
5. The water-soluble polymer of claim 3 , wherein the water-soluble polymer comprises about 0.1 ppm to about 100 ppm covalently cross-linked monomer units.
6. The water-soluble polymer of claim 2 , wherein the water-soluble polymer comprises about 0.1 ppm to about 1000 ppm covalently cross-linked monomer units.
7. The water-soluble polymer of claim 2 , wherein the water-soluble polymer comprises about 0.1 ppm to about 100 ppm covalently cross-linked monomer units.
8. The water-soluble polymer of claim 1 , wherein the water-soluble polymer comprises about 0.1 ppm to about 5000 ppm covalently cross-linked monomer units.
9. The water-soluble polymer of claim 1 , wherein the water-soluble polymer comprises about 0.1 ppm to about 1000 ppm covalently cross-linked monomer units.
10. A composition comprising the water-soluble polymer of claim 2 and water.
11. The composition of claim 10 , further comprising a surfactant, a biocide, an antioxidant, or a combination thereof.
12. The composition of claim 10 , having a viscosity of about 0 cPs to about 100 cPs.
13. The composition of claim 10 , wherein the composition has a viscosity of about 1 cPs to about 5000 cPs after hydrolyzable cross-links of the water-soluble polymer break following exposure to a stimulus.
14. The composition of claim 13 , wherein the stimulus is an increase in temperature.
15. The composition of claim 13 , wherein the stimulus is an increase in pH.
16. The composition of claim 13 , wherein the stimulus is dilution in water.
17. The composition of claim 10 comprising about 100 ppm to about 10000 ppm of the water-soluble polymer.
18. A composition comprising the water-soluble polymer of claim 3 and water.
19. The composition of claim 18 , wherein the composition has a viscosity of about 1 cPs to about 5000 cPs after hydrolyzable cross-links of the water-soluble polymer break following exposure to a stimulus.
20. The composition of claim 18 , comprising about 100 ppm to about 10000 ppm of the water-soluble polymer.