Method for controlling formation permeability

Claim 2

A method according to claim 2 wherein said aqueous compositions essentially free of crosslinkable polymeric materials have additionally incorporated therein at least one multivalent cation.

Claim 3

A method according to claim 2 wherein said formation is contacted with an aqueous composition essentially free of reducing and oxidizing components of said catalyst system spaced between said polymeric material-containing aqueous composition and said nonpolymeric material-containing aqueous composition.

Claim 4

A method according to claim 4 wherein said aqueous composition essentially free of reducing and oxidizing components has incorporated therein at least one crosslinkable polymeric material.

Claim 5

A method according to claim 1 comprising: introducing into said formation a first aqueous composition containing at least one crosslinkable, at least water-dispersible polymeric material and a sensible amount of at least one of a single component selected from the group consisting of the reducing component of a reducing-oxidizing catalyst system or the oxidizing component of said reducing-oxidizing catalyst system; terminating the introduction of said first aqueous composition into said formation; introducing into said formation a second aqueous composition, said second aqueous composition being essentially free of crosslinkable polymeric material, said second aqueous composition having incorporated therein, when said first aqueous composition has incorporated therein at least one of said reducing components of said catalyst system, at least an oxidizing component of said catalyst system, or, when said first aqueous composition has incorporated therein at least one of said oxidizing components of said catalyst system, at least a reducing component of said catalyst system; terminating the introduction of said second aqueous composition; and maintaining said composition in a quiescent state for a period of time to effect mixing of said first and second aqueous compositions and in situ crosslInking of said polymeric material.

Claim 6

A method according to claim 6 wherein there is introduced into said formation, prior to the introduction of said second aqueous composition, an aqueous composition essentially free of reducing and oxidizing components of said catalyst system.

Claim 7

A method according to claim 8 comprising: introducing into said formation a first aqueous composition containing at least one acid selected from the group consisting of organic and inorganic acids; terminating the introduction of said first aqueous composition; introducing into said formation a second aqueous composition containing a sensible amount of at least one oxidizing component of a reducing oxidizing catalyst system; terminating the introduction of said second aqueous composition; introducing into said formation a third aqueous composition containing at least one crosslinkable, at least water-dispersible polymeric material and a sensible amount of at least one reducing component of said reducing-oxidizing catalyst system; terminating the introduction of said third aqueous composition; introducing into said formation a fourth aqueous composition containing a sensible amount of an admixture of at least one reducing component and at least one oxidizing component of said catalyst system; said fourth aqueous composition being essentially free of crosslinkable polymeric material; terminating the introduction of said fourth aqueous composition; introducing into said formation a fifth aqueous composition containing at least one crosslinkable, at least water-dispersible polymeric material and a sensible amount of at least one reducing component of said reducing-oxidizing catalyst system; terminating the introduction of said fifth aqueous composition; introducing into said formation a sixth aqueous composition containing a sensible amount of an admixture of at least one reducing component and at least one oxidizing component of said reducing-oxidizing catalyst system; terminating the introduction of said sixth aqueous composition; introducing into said formation a seventh composition comprising fluid petroleum; maintaining said composition in a quiescent state for a period of time to effect mixing of said compositions and in situ crosslinking of said polymeric material; and thereafter returning said well to production of fluid hydrocarbon.

Claim 8

A method according to claim 8 wherein there is introduced into said formation prior to the introduction of said second, third, fourth, fifth, sixth and seventh compositions an aqueous composition essentially free of crosslinkable polymeric material and essentially free of reducing and oxidizing components of said reducing-oxidizing catalyst system.

Claim 9

A method according to claim 9 wherein said reducing component of said reducing-oxidizing catalyst system incorporated into said third, fourth, fifth and sixth compositions is sodium hydrosulfite; said oxidizing component of said reducing-oxidizing catalyst system incorporated into said second, fourth and sixth compositions is sodium dichromate; said polymeric material incorporated into said third and fifth compositions is partially hydrolyzed polyacrylamide; said acid incorporated into said first composition is hydrochloric acid; said aqueous composition introduced into said formation prior to said seventh composition has incorporated therein at least one biocide and at least one corrosion inhibitor; and said seventh composition is lease crude oil.

Claim 10

A method according to claim 6 wherein there is introduced into said formation an aqueous composition containing at least one acid selected from the group consisting of inorganic and organic acids prior to the introduction into said formation of said first aqueous composition.

Claim 11

A method according to claim 11 comprising: introducing into said formation a first aqueous composition containing at least one acid selected from the group consisting of organic and inOrganic acids; terminating the introduction of said first composition; introducing into said formation a second aqueous composition containing at least one crosslinkable, at least water-dispersible polymeric material and a sensible amount of at least one oxidizing component of a reducing-oxidizing catalyst system; terminating the introduction of said second composition; introducing into said formation a third aqueous composition having incorporated therein a sensible amount of at least one reducing component of said reducing-oxidizing catalyst system; terminating the introduction of said third composition; introducing into said formation a fourth aqueous composition containing at least one crosslinkable, at least water-dispersible polymeric material and having incorporated therein a sensible amount of at least one oxidizing component of said catalyst system; terminating the introduction of said fourth composition; introducing into said formation a fifth aqueous composition having incorporated therein a sensible amount of at least one reducing component of said catalyst system; terminating the introduction of said fifth composition; introducing into said formation a sixth composition comprising fluid petroleum; maintaining said composition in a quiescent state for a period of time to effect mixing of said compositions and in situ crosslinking of said polymeric material; and thereafter returning said well to production of fluid hydrocarbon.

Claim 12

A method according to claim 12 wherein there is introduced into said formation prior to the introduction of said second, third, fourth, fifth and sixth compositions an aqueous composition essentially free of crosslinkable polymeric material and essentially free of reducing and oxidizing components of said catalyst system.

Claim 13

A method according to claim 13 wherein said acid is hydrochloric acid; said reducing component is sodium hydrosulfite; said oxidizing component is sodium dichromate; said polymeric material is partially hydrolyzed polyacrylamide; said fluid petroleum is lease crude oil; and said aqueous composition introduced into said formation prior to said sixth composition has incorporated therein at least one biocide and at least one corrosion inhibitor.

Claim 14

A method according to claim 11 comprising: introducing into said formation a first aqueous composition having incorporated therein at least one acid selected from the group consisting of inorganic and organic acids; terminating the introduction of said first composition; introducing into said formation a second aqueous composition having incorporated therein a sensible amount of at least one reducing component of a reducing-oxidizing catalyst system; terminating the introduction of said second composition; introducing into said formation a third aqueous composition containing at least one crosslinkable, at least water-dispersible polymeric material and having incorporated therein a sensible amount of at least one reducing component of said catalyst system; terminating the introduction of said third composition; introducing into said formation a fourth aqueous composition having incorporated therein a sensible amount of at least one oxidizing component of said catalyst system; terminating the introduction of said fourth composition; introducing into said formation a fifth aqueous composition containing at least one crosslinkable, at least water-dispersible polymeric material and having incorporated therein a sensible amount of at least one reducing component of said catalyst system; terminating the introduction of said fifth composition; introducing into said formation a sixth aqueous composition having incorporated therein a sensible amount of at least one reducing component of said catalyst system; terminating the introduction of said sixth composition; introducing into said formation a seventh composition comprising fluid petroleum; mAintaining said compositions in a quiescent state for a period of time to effect mixing of said compositions and in situ crosslinking of said polymeric material; and thereafter returning said well to production of fluid hydrocarbon.

Claim 15

A method according to claim 15 wherein there is introduced into said formation prior to the introduction of said fourth and fifth compositions an aqueous composition essentially free of crosslinkable polymeric material and essentially free of reducing and oxidizing components of said catalyst system.

Claim 16

A method according to claim 16 wherein said acid is hydrochloric acid; said reducing component is sodium hydrosulfite; said oxidizing compound is sodium dichromate; said polymeric material is partially hydrolyzed polyacrylamide; and said fluid petroleum is lease crude oil.

Claim 17

A process according to claim 1 comprising: introducing into said formation a first aqueous composition containing at least one component selected from the group consisting of the reducing component of a reducing-oxidizing catalyst system or the oxidizing component of said catalyst system, said first aqueous composition being essentially free of crosslinkable polymeric material; terminating the introduction into said formation of said first aqueous composition; introducing into said formation a second aqueous composition containing at least one crosslinkable, at least water-dispersible polymeric material and a sensible amount of at least one of a single component selected from the group consisting of the reducing component or the oxidizing component of a reducing-oxidizing catalyst system; providing that, when said second aqueous system has incorporated therein at least one reducing component of said catalyst system, said first composition has incorporated therein at least an oxidizing component of said catalyst system; and when said second aqueous system has incorporated therein at least one oxidizing component of said catalyst system, said first aqueous system has incorporated therein at least a reducing component of said catalyst system; terminating the introduction into said formation of said second aqueous composition; and maintaining said compositions in a quiescent state for a period of time to effect mixing of said first and second aqueous compositions and in situ crosslinking of said polymeric material.