US4031958A — Plugging of water-producing zones in a subterrane…

Claim 1

Independent Claim 164 words

A method for selectively plugging the permeable water channels of a subterranean formation of nonuniform permeability penetrated by a well, which comprises: (a) introducing a polymer-thickened aqueous solution of a first reactive chemical into said well communicating with said formation, said solution containing a polymer thickening agent added in an amount sufficient to render the solution substantially more viscous than the subsequently injected liquids; (b) followed by introducing a low viscosity inert aqueous spacer liquid into said well; (c) followed by introducing a low viscosity aqueous solution of a second reactive chemical which, in the formation, contacts and reacts with said first reactive chemical to produce an insoluble precipitate or gel; (d) followed by introducing a second low viscosity inert aqueous spacer liquid; and (e) followed by introducing a second aqueous solution of said first reactive chemical which, in the formation, contacts and reacts with the aqueous solution of a second reactive chemical introduced in step (c) to produce an insoluble precipitate or gel.

Claim 2

Independent Claim 164 words

A method for selectively plugging the permeable water channels of a subterranean formation of nonuniform permeability penetrated by a well, which comprises: (a) introducing a polymer-thickened aqueous solution of a first reactive chemical into said well communicating with said formation, said solution containing a polymer thickening agent added in an amount sufficient to render the solution substantially more viscous than the subsequently injected liquids; (b) followed by introducing a low viscosity inert aqueous spacer liquid into said well; (c) followed by introducing a low viscosity aqueous solution of a second reactive chemical which, in the formation, contacts and reacts with said first reactive chemical to produce an insoluble precipitate or gel; (d) followed by introducing a second low viscosity inert aqueous spacer liquid; and (e) followed by introducing a second aqueous solution of said first reactive chemical which, in the formation, contacts and reacts with the aqueous solution of a second reactive chemical introduced in step (c) to produce an insoluble precipitate or gel.

Claim 3

Dependent Claim 25 words

The method defined in claim 1 wherein the second aqueous solution of first reactive chemical injected in step (e) also contains a polymer thickening agent.

Claim 4

Dependent Claim 37 words

The method defined in claim 1 wherein said low viscosity liquids have viscosities of about 1 centipoise and wherein the viscous aqueous solutions have a viscosity within the range of from about 5 to about 100 centipoises.

Claim 5

Dependent Claim 16 words

The method defined in claim 1 wherein said polymer thickening agent is a partially hydrolyzed polyacrylamide.

Claim 6

Dependent Claim 14 words

The method defined in claim 1 wherein said polymer thickening agent is hydroxyethyl cellulose.

Claim 7

Dependent Claim 30 words

The method defined in claim 1 wherein the first reactive chemical is a gelling agent for the alkali metal silicate and the second reactive chemical is an alkali metal silicate.

Claim 8

Dependent Claim 26 words

The method defined in claim 6 wherein the gelling agent for the alkali metal silicate is ammonium sulfate and the alkali metal silicate is sodium silicate.

Claim 9

Dependent Claim 30 words

The method defined in claim 1 wherein the first reactive chemical is an alkali metal silicate and the second reactive chemical is a gelling agent for the alkali metal silicate.

Claim 10

Dependent Claim 26 words

The method defined in claim 8 wherein the alkali metal silicate is sodium silicate and the gelling agent for the alkali metal silicate is ammonium sulfate.

Claim 11

Dependent Claim 19 words

The method defined in claim 1 wherein there is first introduced into the formation a slug of polymer-thickened water.

Claim 12

Dependent Claim 108 words

The method defined in claim 1 wherein the polymer-thickened aqueous solution of a first reactive chemical contains from about 2.5 to about 10 weight percent gelling agent for an alkali metal silicate and from about 0.001 to about 1 weight percent polymer thickening agent, the low viscosity aqueous solution of a second reactive chemical contains from about 0.75 to about 25 weight percent alkali metal silicate and the aqueous solution of a first reactive chemical injected in step (e) contains from about 2.5 to about 10 weight percent gelling agent for an alkali metal silicate and, optionally, from about 0.001 to about 1 weight percent polymer thickening agent.

Claim 13

Dependent Claim 38 words

The method defined in claim 1 wherein in steps (b) and (d) the low viscosity inert spacer liquid is introduced in an amount of about 1 to about 1,000 barrels per vertical foot of interval to be treated.

Claim 14

Dependent Claim 38 words

The method defined in claim 1 wherein in steps (b) and (d) the low viscosity inert spacer liquid is introduced in an amount of about 5 to about 50 barrels per vertical foot of interval to be treated.

Claim 15

Independent Claim 260 words

A method for selectively plugging the permeable water channels of a subterranean formation of nonuniform permeability penetrated by a well, which comprises sequentially: (a) introducing into said well communicating with said formation a slug of from about 1 to about 100 barrels per vertical foot of formation to be treated of an aqueous solution containing from about 0.001 to about 1 weight percent polymer thickening agent and from about 2.5 to about 10 weight percent of a first reactive chemical; (b) introducing a slug of from about 1 to about 1,000 barrels per vertical foot of a low viscosity inert aqueous spacer liquid; (c) introducing a slug of from about 2 to about 1,000 barrels per vertical foot of a low viscosity aqueous solution of from about 0.75 to about 25 weight percent of a second reactive chemical which in the formation contacts and reacts with said first reactive chemical to produce an insoluble precipitate or gel; (d) introducing a second slug of from about 1 to about 1,000 barrels per vertical foot of a low viscosity inert aqueous spacer liquid; and (e) introducing a second slug of from about 1 to about 100 barrels per vertical foot of formation to be treated of an aqueous solution containing from about 0.001 to about 1 weight percent polymer thickening agent and from about 2.5 to about 10 weight percent of said first reactive chemical which, in the formation, contacts and reacts with the aqueous solution of a second reactive chemical introduced in step (c) to produce an insoluble precipitate or gel.

Claim 16

Independent Claim 260 words

A method for selectively plugging the permeable water channels of a subterranean formation of nonuniform permeability penetrated by a well, which comprises sequentially: (a) introducing into said well communicating with said formation a slug of from about 1 to about 100 barrels per vertical foot of formation to be treated of an aqueous solution containing from about 0.001 to about 1 weight percent polymer thickening agent and from about 2.5 to about 10 weight percent of a first reactive chemical; (b) introducing a slug of from about 1 to about 1,000 barrels per vertical foot of a low viscosity inert aqueous spacer liquid; (c) introducing a slug of from about 2 to about 1,000 barrels per vertical foot of a low viscosity aqueous solution of from about 0.75 to about 25 weight percent of a second reactive chemical which in the formation contacts and reacts with said first reactive chemical to produce an insoluble precipitate or gel; (d) introducing a second slug of from about 1 to about 1,000 barrels per vertical foot of a low viscosity inert aqueous spacer liquid; and (e) introducing a second slug of from about 1 to about 100 barrels per vertical foot of formation to be treated of an aqueous solution containing from about 0.001 to about 1 weight percent polymer thickening agent and from about 2.5 to about 10 weight percent of said first reactive chemical which, in the formation, contacts and reacts with the aqueous solution of a second reactive chemical introduced in step (c) to produce an insoluble precipitate or gel.

Claim 17

Dependent Claim 38 words

The method defined in claim 14 wherein in steps (b) and (d) the low viscosity inert spacer liquid is introduced in an amount of about 5 to about 50 barrels per vertical foot of interval to be treated.

Claim 18

Dependent Claim 304 words

In the recovery of oil from a subterranean oil-bearing formation of nonuniform permeability by flooding the formation with an aqueous displacement fluid injected under pressure through an injection well so as to drive oil toward at least one spaced production well, an improved method of selectively adjusting the permeability of the formation, which comprises: (a) discontinuing the injection of the displacement fluid; (b) injecting through said injection well a slug of from about 1 to about 100 barrels per vertical foot of formation to be treated of an aqueous solution containing from about 0.001 to about 1 weight percent polymer thickening agent and from about 2.5 to about 10 weight percent gelling agent for an alkali metal silicate; (c) followed by injecting a slug of from about 1 to about 1,000 barrels per vertical foot of a low viscosity inert aqueous spacer liquid; (d) followed by injecting a slug of from about 2 to about 1,000 barrels per vertical foot of a low viscosity aqueous solution containing from about 0.75 to about 25 weight percent of alkali metal silicate which, in the formation, contacts and reacts with the aqueous solution of polymer and gelling agent injected in step (b) to produce an insoluble precipitate or gel; (e) followed by injecting a second slug of from about 1 to about 1,000 barrels per vertical foot of a low viscosity inert aqueous spacer liquid; (f) followed by injecting a slug of from about 1 to about 100 barrels per vertical foot of an aqueous solution containing from about 2.5 to about 10 weight percent gelling agent for an alkali metal silicate which, in the formation, contacts and reacts with the aqueous solution of alkali metal silicate injected in step (d) to produce an insoluble precipitate or gel; and (g) resuming the injection of the displacement fluid.

Claim 19

Dependent Claim 304 words

In the recovery of oil from a subterranean oil-bearing formation of nonuniform permeability by flooding the formation with an aqueous displacement fluid injected under pressure through an injection well so as to drive oil toward at least one spaced production well, an improved method of selectively adjusting the permeability of the formation, which comprises: (a) discontinuing the injection of the displacement fluid; (b) injecting through said injection well a slug of from about 1 to about 100 barrels per vertical foot of formation to be treated of an aqueous solution containing from about 0.001 to about 1 weight percent polymer thickening agent and from about 2.5 to about 10 weight percent gelling agent for an alkali metal silicate; (c) followed by injecting a slug of from about 1 to about 1,000 barrels per vertical foot of a low viscosity inert aqueous spacer liquid; (d) followed by injecting a slug of from about 2 to about 1,000 barrels per vertical foot of a low viscosity aqueous solution containing from about 0.75 to about 25 weight percent of alkali metal silicate which, in the formation, contacts and reacts with the aqueous solution of polymer and gelling agent injected in step (b) to produce an insoluble precipitate or gel; (e) followed by injecting a second slug of from about 1 to about 1,000 barrels per vertical foot of a low viscosity inert aqueous spacer liquid; (f) followed by injecting a slug of from about 1 to about 100 barrels per vertical foot of an aqueous solution containing from about 2.5 to about 10 weight percent gelling agent for an alkali metal silicate which, in the formation, contacts and reacts with the aqueous solution of alkali metal silicate injected in step (d) to produce an insoluble precipitate or gel; and (g) resuming the injection of the displacement fluid.

Claim 20

Dependent Claim 18 words

The method defined in claim 16 wherein the gelling agent for the alkali metal silicate is ammonium sulfate.

Claim 21

Dependent Claim 14 words

The method defined in claim 16 wherein the alkali metal silicate is sodium silicate.

Claim 22

Dependent Claim 44 words

The method defined in claim 16 wherein there is first injected through the injection well following the discontinuing of the injection of the displacement fluid a slug of from 1 to 10 barrels per vertical foot of formation to be treated of polymer-thickened water.

Claim 23

Dependent Claim 38 words

The method defined in claim 16 wherein in steps (c) and (e) the low viscosity inert spacer liquid is introduced in an amount of about 5 to about 50 barrels per vertical foot of interval to be treated.

Claim 24

Dependent Claim 225 words

In the production of oil via a production well penetrating a subterranean oil-bearing formation of nonuniform permeability wherein an excessive amount of water is produced along with the oil, an improved method of selectively plugging the water-producing zones, which comprises: (a) discontinuing production via the production well; (b) injecting through said production well a slug of from about 1 to about 100 barrels per vertical foot of formation to be treated of an aqueous solution containing from about 0.001 to about 1 weight percent polymer thickening agent and from about 2.5 to about 10 weight percent gelling agent for an alkali metal silicate; (c) injecting a slug of from about 1 to about 1,000 barrels per vertical foot of a low viscosity inert aqueous spacer liquid; (d) injecting a slug of from about 2 to about 1,000 barrels per vertical foot of a low viscosity aqueous solution containing from about 0.75 to about 25 weight percent alkali metal silicate; (e) injecting a second slug of from about 1 to about 1,000 barrels per vertical foot of a low viscosity inert aqueous spacer liquid; (f) injecting a slug of from about 1 to about 100 barrels per vertical foot of an aqueous solution containing from about 2.5 to about 10 weight percent gelling agent for an alkali metal silicate; and (g) resuming production of the well.

Claim 25

Dependent Claim 225 words

In the production of oil via a production well penetrating a subterranean oil-bearing formation of nonuniform permeability wherein an excessive amount of water is produced along with the oil, an improved method of selectively plugging the water-producing zones, which comprises: (a) discontinuing production via the production well; (b) injecting through said production well a slug of from about 1 to about 100 barrels per vertical foot of formation to be treated of an aqueous solution containing from about 0.001 to about 1 weight percent polymer thickening agent and from about 2.5 to about 10 weight percent gelling agent for an alkali metal silicate; (c) injecting a slug of from about 1 to about 1,000 barrels per vertical foot of a low viscosity inert aqueous spacer liquid; (d) injecting a slug of from about 2 to about 1,000 barrels per vertical foot of a low viscosity aqueous solution containing from about 0.75 to about 25 weight percent alkali metal silicate; (e) injecting a second slug of from about 1 to about 1,000 barrels per vertical foot of a low viscosity inert aqueous spacer liquid; (f) injecting a slug of from about 1 to about 100 barrels per vertical foot of an aqueous solution containing from about 2.5 to about 10 weight percent gelling agent for an alkali metal silicate; and (g) resuming production of the well.

Claim 26

Dependent Claim 28 words

The method defined in claim 21 wherein the aqueous solution injected in step (f) also contains from about 0.001 to about 1 weight percent of polymer thickening agent.

Claim 27

Dependent Claim 18 words

The method defined in claim 21 wherein the gelling agent for the alkali metal silicate is ammonium sulfate.

Claim 28

Dependent Claim 14 words

The method defined in claim 21 wherein the alkali metal silicate is sodium silicate.

Claim 29

Dependent Claim 39 words

The method defined in claim 21 wherein there is first injected through the injection well following the discontinuing of production a slug of from 1 to 10 barrels per vertical foot of formation to be treated of polymer-thickened water.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1980-06-27	1980-12-27	1981-06-28	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1984-06-27	1984-12-27	1985-06-28	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1988-06-27	1988-12-27	1989-06-28	$7700.00	Window Closed / Lapsed

Plugging of water-producing zones in a subterranean formation

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