Potassium silicate clay stabilization process

Claim 2

A process for stabilizing clays present in a water-sensitive, subterranean sandstone formation having a matrix, the sandstone formation containing fine particles which interact with aqueous solutions having ionic makeup distinct from connate water to reduce permeability of the formation and fluid flow therethrough, the sandstone formation being penetrated by a well bore in fluid communication therewith, with process comprising: injecting into the matrix of said subterranean sandstone formation via said well bore an aqueous solution consisting essentially of water and potassium silicate, said potassium silicate existing in said aqueous solution as potassium ions and silicate ions, said silicate ions interacting with said sandstone formation in the presence of said potassium ions to effectively render said fine particles relatively insensitive to said aqueous solutions having a distinct ionic makeup, and said potassium silicate being dissolved in said aqueous solution in a quantity sufficient to effectively render said fine particles relatively insensitive to said aqueous solutions having a distinct ionic makeup for a substantial period of time thereby preventing substantial permeability reduction of the formation matrix.

Claim 3

The process of claim 1 wherein said fine particles are clays.

Claim 4

The process of claim 2 wherein said clays comprise swelling clays and migratable clays.

Claim 5

The process of claim 3 wherein said swelling clays are selected from the group consisting of montmorillonite, swelling chlorite, vermiculite, mixed layered swelling clays and mixtures thereof.

Claim 6

The process of claim 3 wherein said migratable clays are selected from the group consisting of poorly cemented kaolinite clays, poorly cemented illite clays and mixtures thereof.

Claim 7

The process of claim 1 wherein said potassium silicate is dissolved in said aqueous solution in a concentration of from about 0.1 wt.% to about 30 wt.%.

Claim 8

The process of claim 6 wherein said potassium silicate is dissolved in said aqueous solution in a concentration of from about 1 wt.% to about 15 wt.%.

Claim 9

The process of claim 7 wherein said potassium silicate is dissolved in said aqueous solution in a concentration of from about 1 wt.% to about 7 wt.%.

Claim 10

The process of claim 1 wherein said aqueous solution having potassium silicate dissolved therein is in contact with said sandstone formation for a period of time from about 1 hour to about 72 hours.

Claim 11

The process of claim 1 wherein said sandstone formation is a hydrocarbon-bearing sandstone formation.

Claim 12

The process of claim 1 wherein said sandstone formation has a temperature of from about 20° C. to about 50° C.

Claim 13

The process of claim 1 wherein said aqueous solution having a distinct ionic makeup is fresh water.

Claim 14

The process of claim 1 wherein the clay stabilization is limited to the near well bore environment of the formation matrix.

Claim 15

A process for stabilizing clays present in a water-sensitive, subterranean sandstone formation having a matrix, the sandstone formation containing fine particles which interact with aqueous solutions having ionic makeup distinct from connate water to reduce permeability of the formation and fluid flow therethrough, the sandstone formation being penetrated by a well bore in fluid communication therewith, the process comprising: injecting into the matrix of said subterranean sandstone formation via said well bore an aqueous solution consisting essentially of water, potassium silicate and potassium hydroxide, said potassium silicate and potasssium hydroxide existing in said aqueous solution as potassium ions, silicate ions and hydroxide ions, said silicate and hydroxide ions interacting with said sandstone formation in the presence of said potassium ions to effectively render said fine particles relatively insensitive to said aqueous solutions having a distinct ionic makeup, and said potassium silicate and potassium hydroxide being dissolved in said aqueous solution in a quantity sufficient to effectively render said fine particles relatively insensitive to said aqueous solutions having a distinct ionic makeup for a substantial period of time, thereby preventing substantial permeability reduction of the formation matrix.

Claim 16

A process for stabilizing clays present in a water-sensitive, subterranean sandstone formation having a matrix, the sandstone formation containing fine particles which interact with aqueous solutions having ionic makeup distinct from connate water to reduce permeability of the formation and fluid flow therethrough, the sandstone formation being penetrated by a well bore in fluid communication therewith, the process comprising: injecting into the matrix of said subterranean sandstone formation via said well bore an aqueous solution consisting essentially of water, potassium silicate and potassium hydroxide, said potassium silicate and potasssium hydroxide existing in said aqueous solution as potassium ions, silicate ions and hydroxide ions, said silicate and hydroxide ions interacting with said sandstone formation in the presence of said potassium ions to effectively render said fine particles relatively insensitive to said aqueous solutions having a distinct ionic makeup, and said potassium silicate and potassium hydroxide being dissolved in said aqueous solution in a quantity sufficient to effectively render said fine particles relatively insensitive to said aqueous solutions having a distinct ionic makeup for a substantial period of time, thereby preventing substantial permeability reduction of the formation matrix.

Claim 17

The process of claim 14 wherein said fine particles are clays.

Claim 18

The process of claim 15 wherein said clays comprise swelling clays and migratable clays.

Claim 19

The process of claim 16 wherein said swelling clays are selected from the group consisting of montmorillonite, swelling chlorite, vermiculite, mixed layered swelling clays and mixtures thereof.

Claim 20

The process of claim 16 wherein said migratable clays are selected from the group consisting of poorly cemented kaolinite clays, poorly cemented illite clays and mixtures thereof.

Claim 21

The process of claim 14 wherein said potassium silicate is dissolved in said aqueous solution in a concentration of from about 0.1 wt.% to about 15 wt.%.

Claim 22

The process of claim 19 wherein said potassium silicate is dissolved in said aqueous solution in a concentration of from about 0.3 wt.% to about 10 wt.%.

Claim 23

The process of claim 19 wherein said potassium hydroxide is dissolved in said aqueous solution in a concentration of from about 1 wt.% to about 30 wt.% in an inverse relation to said concentration of potassium silicate.

Claim 24

The process of claim 14 wherein said aqueous solution having potassium silicate and potassium hydroxide dissolved therein is in contact with said sandstone formation for a period of time from about 1 hour to about 72 hours.

Claim 25

The process of claim 14 wherein said sandstone formation is a hydrocarbon-bearing sandstone formation.

Claim 26

The process of claim 14 wherein said sandstone formation has a temperature of from about 22° C. to about 85° C. and above.

Claim 27

The process of claim 14 wherein said aqueous solution having a distinct ionic makeup is fresh water.

Claim 28

The process of claim 14 wherein the clay stabilization is limited to the near well bore environment of the formation matrix.

Claim 29

A process for stabilizing clays present in a water-sensitive, subterranean sandstone formation having a matrix, the sandstone formation containing fine particles which interact with aqueous solutions having ionic makeup distinct from connate water to reduce permeability of the formation and fluid flow therethrough, the sandstone formation being penetrated by a well bore in fluid communication therewith, the process comprising: injecting into the matrix of said subterranean sandstone formation via said well bore an aqueous solution consisting essentially of water and potassium silicate and one or more potassium salts, said potassium silicate existing in said aqueous solution as potassium ions and silicate ions, said silicate ions interacting with said sandstone formation in the presence of said potassium ions to effectively render said fine particles relatively insensitive to said aqueous solutions having a distinct ionic makeup, and said potassium silicate being dissolved in said aqueous solution in a quantity sufficient to effectively render said fine particles relatively insensitive to said aqueous solutions having a distinct ionic makeup for a substantial period of time thereby preventing substantial permeability reduction of the formation matrix.

Claim 30

A process for stabilizing clays present in a water-sensitive, subterranean sandstone formation having a matrix, the sandstone formation containing fine particles which interact with aqueous solutions having ionic makeup distinct from connate water to reduce permeability of the formation and fluid flow therethrough, the sandstone formation being penetrated by a well bore in fluid communication therewith, the process comprising: injecting into the matrix of said subterranean sandstone formation via said well bore an aqueous solution consisting essentially of water and potassium silicate and one or more potassium salts, said potassium silicate existing in said aqueous solution as potassium ions and silicate ions, said silicate ions interacting with said sandstone formation in the presence of said potassium ions to effectively render said fine particles relatively insensitive to said aqueous solutions having a distinct ionic makeup, and said potassium silicate being dissolved in said aqueous solution in a quantity sufficient to effectively render said fine particles relatively insensitive to said aqueous solutions having a distinct ionic makeup for a substantial period of time thereby preventing substantial permeability reduction of the formation matrix.

Claim 31

A process for stabilizing clays present in a water-sensitive, subterranean sandstone formation having a matrix, the sandstone formation containing fine particles which interact with aqueous solutions having ionic makeup distinct from connate water to reduce permeability of the formation and fluid flow therethrough, the sandstone formation being penetrated by a well bore in fluid communication therewith, the process comprising: injecting into the matrix of said subterranean sandstone formation via said well bore an aqueous solution consisting essentially of water, potassium silicate and potassium hydroxide and one or more potassium salts, said potassium silicate and potassium hydroxide existing in said aqueous solution as potassium ions, silicate ions and hydroxide ions, said silicate and hydroxide ions interacting with said sandstone formation in the presence of said potassium ions to effectively render said fine particles relatively insensitive to said aqueous solutions having a distinct ionic makeup, and said potassium silicate and potassium hydroxide being dissolved in said aqueous solution in a quantity sufficient to effectively render said fine particles relatively insensitive to said aqueous solutions having a distinct ionic makeup for a substantial period of time, thereby preventing substantial permeability reduction of the formation matrix.

Claim 32

A process for stabilizing clays present in a water-sensitive, subterranean sandstone formation having a matrix, the sandstone formation containing fine particles which interact with aqueous solutions having ionic makeup distinct from connate water to reduce permeability of the formation and fluid flow therethrough, the sandstone formation being penetrated by a well bore in fluid communication therewith, the process comprising: injecting into the matrix of said subterranean sandstone formation via said well bore an aqueous solution consisting essentially of water, potassium silicate and potassium hydroxide and one or more potassium salts, said potassium silicate and potassium hydroxide existing in said aqueous solution as potassium ions, silicate ions and hydroxide ions, said silicate and hydroxide ions interacting with said sandstone formation in the presence of said potassium ions to effectively render said fine particles relatively insensitive to said aqueous solutions having a distinct ionic makeup, and said potassium silicate and potassium hydroxide being dissolved in said aqueous solution in a quantity sufficient to effectively render said fine particles relatively insensitive to said aqueous solutions having a distinct ionic makeup for a substantial period of time, thereby preventing substantial permeability reduction of the formation matrix.