Gel for retarding water flow

Claim 2

A process for retarding the flow of water in a subterranean zone comprising introducing an effective amount of a gel-forming composition into a subterranean zone, said gel-forming composition being operable when gelled in said zone for retarding the flow of water therein, said gel-forming composition being formable into a gel in the presence of an acidic catalyst from i. an aqueous solution comprising a first substance selected from the group consisting of polyvinyl alcohol, a polyvinyl alcohol copolymer, and mixtures thereof, and ii. a second substance comprising an aldehyde.

Claim 3

The process of claim 1, wherein said gel-forming composition comprises water, and wherein said water provides at least about 95% of the weight of said gel.

Claim 4

The process of claim 2, wherein said water provides at least about 96% of the weight of said gel.

Claim 5

The process of claim 2, wherein said water provides at least about 97% of the weight of said gel.

Claim 6

The process of claim 2, wherein said water provides at least about 98% of the weight of said gel.

Claim 7

The process of claim 2, further comprising treating said gel with a basic substance.

Claim 8

The process of claim 2, wherein said water has a hardness of at least about 1000 ppm.

Claim 9

The process of claim 2, wherein said first substance has an average molecular weight of at least about 100,000.

Claim 10

The process of claim 2, wherein said water has a pH between about 2.5 and about 4.5.

Claim 11

The process of claim 1, wherein said first substance is a polyvinyl alcohol having an average molecular weight of at least about 100,000, wherein said polyvinyl alcohol is about 0.5 to about 5% of the weight of said gel, and wherein said aldehyde is a dialdehyde selected from the group consisting of glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, adipaldehyde, and mixtures thereof, wherein said dialdehyde is about 0.005 to about 2.5% of the weight of said gel.

Claim 12

The process of claim 10, wherein said dialdehyde is malonaldehyde.

Claim 13

The process of claim 10, wherein said dialdehyde is glutaraldehyde.

Claim 14

The process of claim 1, wherein said first substance has crosslinkable sites and wherein the amount of said aldehyde is adjusted so that stoichiometrically no more than about 8% of said crosslinkable sites of said first substance can be crosslinked with said aldehyde.

Claim 15

The process of claim 13, wherein said amount of said aldehyde is adjusted so that stoichiometrically no more than about 4% of said crosslinkable sites of said first substance can be crosslinked with said aldehyde.

Claim 16

The gel of claim 13, wherein said amount of said aldehyde is adjusted so that stoichiometrically no more than about 2% of said crosslinkable sites of said first substance can be crosslinked with said aldehyde.

Claim 17

The gel of claim 13, wherein said amount of said aldehyde is adjusted so that stoichiometrically no more than about 1% of said crosslinkable sites of said first substance can be crosslinked with said aldehyde.

Claim 18

The gel of claim 13, wherein said water has a hardness of at least about 1000 ppm.

Claim 19

The gel of claim 13, wherein said water has a pH between about 2.5 and 4.5.

Claim 20

The gel of claim 13, wherein said aldehyde is at least about 50 wt% malonaldehyde.

Claim 21

The gel of claim 13, wherein said aldehyde is at least about 50 wt% glutaraldehyde.

Claim 22

The process of claim 13, further comprising treating said gel with a basic substance to neutralize said gel.

Claim 23

The process of claim 1, wherein said first substance is a polyvinyl alcohol having crosslinkable sites, and wherein said aldehyde is a dialdehyde, the amount of said dialdehyde being adjusted so that stoichiometrically no more than about 8% of said crosslinkable sites of said polyvinyl alcohol can be crosslinked with said dialdehyde.

Claim 24

The process of claim 1, wherein said first substance is a polyvinyl alcohol having crosslinkable sites and an average molecular weight of at least about 100,000, wherein said polyvinyl alcohol is about 0.5 to about 5% of the weight of said gel, and wherein said aldehyde is a dialdehyde selected from the group consisting of glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, adipaldehyde, and mixtures thereof, wherein said dialdehyde is about 0.005 to about 2.5% of the weight of said gel, the amount of said dialdehyde being adjusted so that stoichiometrically no more than about 8% of said crosslinkable sites of said polyvinyl alcohol can be crosslinked with said dialdehyde.

Claim 25

The process of claim 23, wherein said dialdehyde is malonaldehyde.

Claim 26

The process of claim 23, wherein said dialdehyde is glutaraldehyde.

Claim 27

The process of claim 1, wherein said acidic catalyst is selected from the group consisting of acetin, diacetin, and mixtures thereof.

Claim 28

A process for retarding the flow of water in a subterranean zone comprising: (a) introducing an effective amount of a gel-forming composition into a subterranean zone, said gel-forming composition being operable when gelled in said zone for retarding the flow of water therein, said gel-forming composition being formed, in the presence of an acidic catalyst, into a gel by reacting i. an aqueous solution comprising a first substance selected from the group consisting of polyvinyl alcohol, a polyvinyl alcohol copolymer, and mixtures thereof, and ii. a second substance comprising an aldehyde; and (b) allowing said aqueous solution and said aldehyde to react in said zone and to form a gel therein which is effective for retarding the flow of water in said zone.

Claim 29

A process for retarding the flow of water in a subterranean zone comprising: (a) introducing an effective amount of a gel-forming composition into a subterranean zone, said gel-forming composition being operable when gelled in said zone for retarding the flow of water therein, said gel-forming composition being formed, in the presence of an acidic catalyst, into a gel by reacting i. an aqueous solution comprising a first substance selected from the group consisting of polyvinyl alcohol, a polyvinyl alcohol copolymer, and mixtures thereof, and ii. a second substance comprising an aldehyde; and (b) allowing said aqueous solution and said aldehyde to react in said zone and to form a gel therein which is effective for retarding the flow of water in said zone.

Claim 30

The process of claim 27, wherein said subterranean zone has a temperature of at least about 65° C.

Claim 31

The process of claim 27, wherein said subterranean zone has a temperature of at least about 80° C.

Claim 32

The process of claim 27, wherein said subterranean zone has a temperature of at least about 125° C.

Claim 33

The process of claim 27, wherein said aqueous solution is formed from water having a hardness of at least about 1000 ppm.

Claim 34

The process of claim 27, wherein said gel-forming composition comprises water, and wherein said water provides about 95 to about 99% of the weight of said gel.

Claim 35

A process for retarding the flow of water while producing hydrocarbons from a subterranean hydrocarbon-producing zone comprising: (a) introducing an effective amount of a gel-forming composition into a subterranean water-conveying zone, which is in water communication with a subterranean hydrocarbon-producing zone, said gel-forming composition being operable when gelled in said subterranean water-conveying zone for retarding the flow of water therein, said gel-forming composition being formed, in the presence of an acidic catalyst, into a gel by reacting i. an aqueous solution comprising a first substance selected from the group consisting of a polyvinyl alcohol, a polyvinyl alcohol copolymer, and mixtures thereof, and ii. a second substance comprising an aldehyde; (b) allowing said aqueous solution and said aldehyde to react in the presence of said acidic catalyst in said subterranean water-conveying zone to form a gel therein which is operable for retarding the flow of water in said subterranean water-conveying zone and retarding the production of water when producing hydrocarbons from said hydrocarbon-producing zone; and (c) producing hydrocarbons and retarding the production of water from said subterranean hydrocarbon-producing zone.

Claim 36

A process for retarding the flow of water while producing hydrocarbons from a subterranean hydrocarbon-producing zone comprising: (a) introducing an effective amount of a gel-forming composition into a subterranean water-conveying zone, which is in water communication with a subterranean hydrocarbon-producing zone, said gel-forming composition being operable when gelled in said subterranean water-conveying zone for retarding the flow of water therein, said gel-forming composition being formed, in the presence of an acidic catalyst, into a gel by reacting i. an aqueous solution comprising a first substance selected from the group consisting of a polyvinyl alcohol, a polyvinyl alcohol copolymer, and mixtures thereof, and ii. a second substance comprising an aldehyde; (b) allowing said aqueous solution and said aldehyde to react in the presence of said acidic catalyst in said subterranean water-conveying zone to form a gel therein which is operable for retarding the flow of water in said subterranean water-conveying zone and retarding the production of water when producing hydrocarbons from said hydrocarbon-producing zone; and (c) producing hydrocarbons and retarding the production of water from said subterranean hydrocarbon-producing zone.

Claim 37

The process of claim 33, wherein said subterranean water-conveying zone is under said subterranean hydrocarbon-producing zone.

Claim 38

The process of claim 33, wherein said subterranean water-conveying zone surrounds said subterranean hydrocarbon-producing zone.

Claim 39

The method of claim 35, wherein said subterranean zone has a temperature of at least about 125° C.

Claim 40

The method of claim 35, wherein said catalyst is a Bronsted acid.

Claim 41

The method of claim 35, wherein said catalyst is a Lewis acid.

Claim 42

The process of claim 33, wherein at least a part of said subterranean water-conveying zone coincides with at least a part of said subterranean hydrocarbon-producing zone.

Claim 43

The process of claim 33, wherein said subterranean water-conveying zone has a temperature of at least 65° C.

Claim 44

The process of claim 33, wherein said subterranean water-conveying zone has a temperature of at least about 80° C.

Claim 45

The process of claim 33, wherein said subterranean water-conveying zone has a temperature of at least about 125° C.

Claim 46

The process of claim 33, wherein said aqueous solution is formed from water having a hardness of at least about 1000 ppm.

Claim 47

A process for retarding the flow of water while producing hydrocarbons from a subterranean hydrocarbon-producing zone comprising: (a) introducing an effective amount of a gel-forming composition into a subterranean water-conveying zone, which is in water communication with a subterranean hydrocarbon-producing zone, said gel-forming composition being operable when gelled in said subterranean water-conveying zone for retarding the flow of water therein, said gel-forming composition being formed, in the presence of an acidic catalyst, into a gel by reacting i. an aqueous solution of a polyvinyl alcohol, and ii. a second substance comprising a dialdehyde; (b) allowing said aqueous solution and said dialdehyde to react, in the presence of said acidic catalyst, in said subterranean water-conveying zone to form a gel therein which is operable for retarding the flow of water in said subterranean water-conveying zone and retarding the production of water when producing hydrocarbons from said hydrocarbon-producing zone, wherein the water of said gel-forming composition provides about 95 to about 99% of the weight of said gel; (c) producing hydrocarbons and retarding the production of water from said subterranean hydrocarbon-producing zone.

Claim 48

A process for retarding the flow of water while producing hydrocarbons from a subterranean hydrocarbon-producing zone comprising: (a) introducing an effective amount of a gel-forming composition into a subterranean water-conveying zone, which is in water communication with a subterranean hydrocarbon-producing zone, said gel-forming composition being operable when gelled in said subterranean water-conveying zone for retarding the flow of water therein, said gel-forming composition being formed, in the presence of an acidic catalyst, into a gel by reacting i. an aqueous solution of a polyvinyl alcohol, and ii. a second substance comprising a dialdehyde; (b) allowing said aqueous solution and said dialdehyde to react, in the presence of said acidic catalyst, in said subterranean water-conveying zone to form a gel therein which is operable for retarding the flow of water in said subterranean water-conveying zone and retarding the production of water when producing hydrocarbons from said hydrocarbon-producing zone, wherein the water of said gel-forming composition provides about 95 to about 99% of the weight of said gel; (c) producing hydrocarbons and retarding the production of water from said subterranean hydrocarbon-producing zone.

Claim 49

A process for retarding the flow of water and producing hydrocarbons from a subterranean hydrocarbon-producing zone comprising: (a) introducing an effective amount of a gel-forming composition into a subterranean water-conveying zone, which is in water communication with a subterranean hydrocarbon-producing zone, said gel-forming composition being operable when gelled in said subterranean water-conveying zone for retarding the flow of water therein, said gel-forming composition being formed, in the presence of an acidic catalyst, into a gel by reacting i. an aqueous solution of a polyvinyl alcohol having an average molecular weight of at least 100,000, and ii. a second substance comprising a dialdehyde selected from the group consisting of glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, adipaldehyde, and mixtures thereof; (b) allowing said aqueous solution and said dialdehyde to react, in the presence of said acidic catalyst, in said subterranean water-conveying zone to form a gel therein which is operable for retarding the flow of water in said subterranean water-conveying zone and retarding the production of water when producing hydrocarbons from said hydrocarbon-producing zone, wherein the amount of said polyvinyl alcohol is about 0.5 to about 5% of the weight of said gel, wherein the amount of said dialdehyde is about 0.005 to about 2.5% of the weight of said gel, and wherein the water of said gel-forming composition provides about 95 to about 99% of the weight of said gel; and (c) producing hydrocarbons and retarding the production of water from said subterranean hydrocarbon-producing zone.

Claim 50

A process for retarding the flow of water and producing hydrocarbons from a subterranean hydrocarbon-producing zone comprising: (a) introducing an effective amount of a gel-forming composition into a subterranean water-conveying zone, which is in water communication with a subterranean hydrocarbon-producing zone, said gel-forming composition being operable when gelled in said subterranean water-conveying zone for retarding the flow of water therein, said gel-forming composition being formed, in the presence of an acidic catalyst, into a gel by reacting i. an aqueous solution of a polyvinyl alcohol having an average molecular weight of at least 100,000, and ii. a second substance comprising a dialdehyde selected from the group consisting of glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, adipaldehyde, and mixtures thereof; (b) allowing said aqueous solution and said dialdehyde to react, in the presence of said acidic catalyst, in said subterranean water-conveying zone to form a gel therein which is operable for retarding the flow of water in said subterranean water-conveying zone and retarding the production of water when producing hydrocarbons from said hydrocarbon-producing zone, wherein the amount of said polyvinyl alcohol is about 0.5 to about 5% of the weight of said gel, wherein the amount of said dialdehyde is about 0.005 to about 2.5% of the weight of said gel, and wherein the water of said gel-forming composition provides about 95 to about 99% of the weight of said gel; and (c) producing hydrocarbons and retarding the production of water from said subterranean hydrocarbon-producing zone.

Claim 51

The process of claim 45, wherein said dialdehyde is malonaldehyde.

Claim 52

The process of claim 45, wherein said dialdehyde is glutaraldehyde.

Claim 53

The process claim 45, wherein said acidic catalyst is selected from the group consisting of acetin, diacetin, and mixtures thereof.

Claim 56

The method of claim 49, wherein said aqueous solution has a pH between about 2 and about 5.

Claim 57

The method of claim 49, wherein said subterranean zone has a temperature of at least about 80° C.

Claim 60

A process for retarding the flow of water by forming, in situ, a gel in a subterranean zone comprising: (a) introducing an aqueous solution of a polyvinyl alcohol into the voids of a subterranean zone, said polyvinyl alcohol having an average molecular weight of at least about 100,000; (b) introducing a substance comprising a dialdehyde into said voids, said dialdehyde being selected from the group consisting of glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, adipaldehyde, and mixtures thereof; and (c) forming a gel in said voids by the reaction of said aqueous solution with said substance, in the presence of an acidic catalyst, wherein said polyvinyl alcohol is about 0.5 to about 5% of the weight of said gel, wherein said dialdehyde is about 0.005 to about 2.5% of the weight of said gel, and wherein the water of said aqueous solution and said substance provides about 95 to about 99% of the weight of said gel thereby retarding the flow of water in said subterranean zone.

Claim 61

A process for retarding the flow of water by forming, in situ, a gel in a subterranean zone comprising: (a) introducing an aqueous solution of a polyvinyl alcohol into the voids of a subterranean zone, said polyvinyl alcohol having an average molecular weight of at least about 100,000; (b) introducing a substance comprising a dialdehyde into said voids, said dialdehyde being selected from the group consisting of glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, adipaldehyde, and mixtures thereof; and (c) forming a gel in said voids by the reaction of said aqueous solution with said substance, in the presence of an acidic catalyst, wherein said polyvinyl alcohol is about 0.5 to about 5% of the weight of said gel, wherein said dialdehyde is about 0.005 to about 2.5% of the weight of said gel, and wherein the water of said aqueous solution and said substance provides about 95 to about 99% of the weight of said gel thereby retarding the flow of water in said subterranean zone.

Claim 62

The process of claim 53, wherein said dialdehyde is malonaldehyde.

Claim 63

The process of claim 53, wherein said dialdehyde is glutaraldehyde.

Claim 64

The process of claim 53, wherein said acidic catalyst is selected from the group consisting of acetin, diacetin, and mixtures thereof.

Claim 67

The method of claim 57, wherein said acidic catalyst is a Bronsted acid.

Claim 68

The method of claim 57, wherein said acidic catalyst is a Lewis acid.

Claim 69

The method of claim 57, wherein said acidic catalyst is a delayed action catalyst.

Claim 70

The method of claim 57, wherein said aqueous solution and said second substance are introduced into said voids in one time period, and said third substance is introduced into said voids in another time period which is different from said first mentioned time period.

Claim 71

The method of claim 57, wherein said aqueous solution is introduced into said voids in one time period, and said second substance and said third substance are introduced into said voids in another time period which is different from said first mentioned time period.

Claim 72

The method of claim 57, further comprising mixing said aqueous solution, said second substance, and said third substance together before introducing them into said voids.

Claim 73

The method of claim 63, wherein said acidic catalyst is a delayed action catalyst.

Claim 76

A process for retarding the flow of water by forming, in situ, a gel in a subterranean zone comprising: (a) introducing an aqueous solution of a polyvinyl alcohol into the voids of a subterranean zone, said polyvinyl alcohol having an average molecular weight of at least about 100,000; (b) introducing a second substance comprising a dialdehyde into said voids, said dialdehyde being selected from the group consisting of glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, adipaldehyde, and mixtures thereof; (c) introducing a third substance comprising an acidic catalyst into said voids; and (d) forming a gel in said voids by the reaction of said aqueous solution with said second substance, in the presence of said third substance, wherein said polyvinyl alcohol is about 0.5 to about 5% of the weight of said gel, wherein said dialdehyde is about 0.005 to about 2.5% of the weight of said gel, and wherein the water of said aqueous solution, said second substance and said third substance provides about 95 to about 99% of the weight of said gel thereby retarding the flow of water in said subterranean zone.

Claim 77

A process for retarding the flow of water by forming, in situ, a gel in a subterranean zone comprising: (a) introducing an aqueous solution of a polyvinyl alcohol into the voids of a subterranean zone, said polyvinyl alcohol having an average molecular weight of at least about 100,000; (b) introducing a second substance comprising a dialdehyde into said voids, said dialdehyde being selected from the group consisting of glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, adipaldehyde, and mixtures thereof; (c) introducing a third substance comprising an acidic catalyst into said voids; and (d) forming a gel in said voids by the reaction of said aqueous solution with said second substance, in the presence of said third substance, wherein said polyvinyl alcohol is about 0.5 to about 5% of the weight of said gel, wherein said dialdehyde is about 0.005 to about 2.5% of the weight of said gel, and wherein the water of said aqueous solution, said second substance and said third substance provides about 95 to about 99% of the weight of said gel thereby retarding the flow of water in said subterranean zone.

Claim 78

The process of claim 66, wherein said dialdehyde is malonaldehyde.

Claim 79

The process of claim 66, wherein said dialdehyde is glutaraldehyde.

Claim 80

A process for retarding the flow of water by forming, in situ, a gel in a subterranean zone comprising: (a) introducing an aqueous solution of a polyvinyl alcohol into the voids of a subterranean zone, said polyvinyl alcohol having an average molecular weight of at least about 100,000; (b) introducing a second substance comprising a dialdehyde into said voids, said dialdehyde being selected from the group consisting of glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, adipaldehyde, and mixtures thereof; (c) introducing a third substance comprising a delayed action catalyst into said voids, said delayed action catalyst being selected from the group consisting of acetin, diacetin, and mixtures thereof; and (d) forming a gel in said voids by the reaction of said aqueous solution with said second substance, in the presence of said third substance, wherein said polyvinyl alcohol is about 0.5 to about 5% of the weight of said gel, wherein said dialdehyde is about 0.005 to about 2.5% of the weight of said gel, and wherein the water of said aqueous solution, said second substance and said third substance provides about 95 to about 99% of the weight of said gel thereby retarding the flow of water in said subterranean zone.

Claim 81

A process for retarding the flow of water by forming, in situ, a gel in a subterranean zone comprising: (a) introducing an aqueous solution of a polyvinyl alcohol into the voids of a subterranean zone, said polyvinyl alcohol having an average molecular weight of at least about 100,000; (b) introducing a second substance comprising a dialdehyde into said voids, said dialdehyde being selected from the group consisting of glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, adipaldehyde, and mixtures thereof; (c) introducing a third substance comprising a delayed action catalyst into said voids, said delayed action catalyst being selected from the group consisting of acetin, diacetin, and mixtures thereof; and (d) forming a gel in said voids by the reaction of said aqueous solution with said second substance, in the presence of said third substance, wherein said polyvinyl alcohol is about 0.5 to about 5% of the weight of said gel, wherein said dialdehyde is about 0.005 to about 2.5% of the weight of said gel, and wherein the water of said aqueous solution, said second substance and said third substance provides about 95 to about 99% of the weight of said gel thereby retarding the flow of water in said subterranean zone.

Claim 82

The process of claim 69, wherein said dialdehyde is selected from the group consisting of malonaldehyde, glutaraldehyde, and mixtures thereof.