Enhanced oil recovery

Patent metadata

Field	Value
Publication number	US-2025257640-A1
Application number	US-202418439583-A
Country	US
Kind code	A1
Filing date	Feb 12, 2024
Priority date	Feb 12, 2024
Publication date	Aug 14, 2025
Grant date	—

Abstract

The present disclosure relates to methods for enhanced oil recovery (EOR) from a subterranean formation by injecting a mixture including an anionic surfactant and an amine, followed by injecting CO2, to reduce CO2 mobility in a high-permeability zone of the formation.

First claim

What is claimed is:

1 . A method of enhanced oil recovery (EOR) from a subterranean formation comprising a high-permeability zone and a low-permeability zone, the method comprising:
injecting, through a wellbore into the high-permeability zone, a mixture comprising an anionic surfactant and an amine and having a viscosity of less than about 0.01 Pas at a shear rate from about 0.1 to about 1000 s −1 ; injecting CO 2 through the wellbore into the high-permeability zone to increase a viscosity of the mixture in the high-permeability zone, wherein increasing the viscosity of the mixture reduces a mobility of CO 2 in the high-permeability zone; and injecting CO 2 through the wellbore into the low-permeability zone to stimulate a flow of hydrocarbons from the low-permeability zone.

2 . The method of claim 1 , wherein the anionic surfactant comprises a carboxylate surfactant, a sulfonate surfactant, a sulfate surfactant, or any combination thereof.

3 . The method of claim 2 , wherein the anionic surfactant comprises an alkyl group, an alkenyl group, or an alkyl alcohol ether group.

4 . The method of claim 3 , wherein the alkyl group comprises a C 12-22 alkyl group.

5 . The method of claim 3 , wherein the alkyl group comprises a C 12-22 alkenyl group.

6 . The method of claim 3 , wherein the alkyl alcohol ether group comprises a C 12-22 alkyl alcohol polyoxyethylene group.

7 . The method of claim 2 , wherein the anionic surfactant comprises a compound of Formula I, Formula II, or Formula III:

wherein:
R 1 is

the sum of m and q is an integer from 12 to 22;
n is an integer from 0 to 10;
p is 0 or 1; and
X + is Li + , Na + , K + , Cs + , Ag + , or (R A ) 4 N + , wherein
each occurrence of R A is selected from H, C 1-6 alkyl, C 3-6 cycloalkyl, 4- to 7-membered heterocycloalkyl, C 6-10 aryl, and 5- to 10-membered heteroaryl;
each C 1-6 alkyl is optionally substituted with 1-3 R B independently selected from C 3-6 cycloalkyl, 4- to 7-membered heterocycloalkyl, C 6-10 aryl, and 5- to 10-membered heteroaryl; and
optionally, one or more instances of R A are taken together with the nitrogen atom to which they are attached to form a 4- to 7-membered heterocycloalkyl.

8 . The method of claim 7 , wherein
n is from 1 to 10; and p is 1.

9 . The method of claim 7 , wherein n, p, and q are each 0.

10 . The method of claim 2 , wherein the anionic surfactant comprises sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium hexadecyl sulfate, sodium octadecyl sulfate, or any combination thereof.

11 . The method of claim 1 , wherein the amine comprises an alkylene diamine, alkylene triamine, alkanolamine, or any combination thereof.

12 . The method of claim 1 , wherein the amine comprises a compound of Formula IV:

wherein
R 2 is selected from C 1-6 alkyl, C 3-6 cycloalkyl, 4- to 7-membered heterocycloalkyl, C 6-10 aryl, and 5- to 10-membered heteroaryl;
R 3 and R 4 are each independently selected from —H, C 1-6 alkyl, C 3-6 cycloalkyl, 4- to 7-membered heterocycloalkyl, C 6-10 aryl, and 5- to 10-membered heteroaryl;
each C 1-6 alkyl and C 6-10 aryl is optionally substituted with 1-3 R C ;
each R C is independently selected from —OH and —N(R D ) 2 ; and
each R D is independently selected from —H and C 1-4 alkyl.

13 . The method of claim 12 , wherein
R 2 is C 1-6 alkyl or phenyl; R 3 and R 4 are each independently selected from —H, C 1-6 alkyl, and phenyl; and each R C is independently selected from —OH and —NH 2 .

14 . The method of claim 1 , wherein the amine comprises diethylene triamine, bis(hexamethylene) triamine, 2-(dimethylamino) ethanol, or any combination thereof.

15 . The method of claim 1 , wherein the anionic surfactant and the amine are present in the mixture in a molar ratio of about 5:1 to about 1:5.

16 . The method of claim 1 , wherein the anionic surfactant and the amine are present in the mixture in a molar ratio of about 2:1 to about 1:2.

17 . The method of claim 1 , wherein a total concentration of the anionic surfactant and the amine in the high-permeability zone after injecting the mixture is about 0.01 mol/L to about 2 mol/L.

18 . The method of claim 1 , wherein a total concentration of the anionic surfactant and the amine in the high-permeability zone after injecting the mixture is about 0.1 mol/L to about 0.75 mol/L.

19 . The method of claim 1 , wherein the viscosity of the mixture before injecting CO 2 is less than about 0.005 Pa·s at a shear rate from about 0.1 to about 1000 s −1 .

20 . The method of claim 1 , wherein injecting CO 2 increases the viscosity of the mixture in the high-permeability zone to greater than about 0.01 Pa·s at a shear rate from about 0.1 to about 1000 s −1 .

21 . The method of claim 1 , wherein a depth of the low-permeability zone is greater than a depth of the high-permeability zone.

22 . A method of enhanced oil recovery (EOR) from a subterranean formation comprising a high-permeability zone and a low-permeability zone, the method comprising:
expanding an upper seal of the straddle packer above the high-permeability zone and expanding a lower seal of the straddle packer below the high-permeability zone to mechanically isolate the high-permeability zone; injecting a mixture comprising an anionic surfactant and an amine through the straddle packer into the high-permeability zone; injecting CO 2 through the wellbore into the high-permeability zone to increase a viscosity of the mixture in the high-permeability zone, wherein increasing the viscosity of the mixture reduces a mobility of CO 2 in the high-permeability zone; removing the straddle packer from the wellbore after increasing the viscosity of the mixture; and injecting CO 2 through the wellbore into the low-permeability zone to stimulate a flow of hydrocarbons from the low-permeability zone.

Assignees

• Saudi Arabian Oil Co

Inventors

• Al-Yousif Zuhair
• Han Ming
• Huang Tianping
• Chen Shaohua

Classifications

• C09K8/594

  Compositions used in combination with injected gas {, e.g. CO2 orcarbonated gas}(C09K8/592 takes precedence) · CPC title

• C09K8/584

  characterised by the use of specific surfactants · CPC title

• E21B43/164 Primary

  Injecting CO2 or carbonated water (in combination with organic material C09K8/594) · CPC title