Storable water-silica suspensions and methods

Abstract

Storable water-silica suspensions and methods of cementing well bores are provided. The storable water-silica suspensions are basically comprised of water, silica and an effective amount of a suspending agent selected from the group consisting of colloidal materials, clays and gel forming polymers.

What is claimed is:  
     
         1 . A storable water-silica suspension comprising: 
 water;    silica selected from the group consisting of micro-silica, silica flour and mixtures thereof; and    an effective amount of a suspending agent selected from the group consisting of colloidal materials, clays and gel forming polymers.    
     
     
         2 . The suspension of  claim 1  wherein said water is selected from the group consisting of fresh water and salt water.  
     
     
         3 . The suspension of  claim 1  wherein said silica is a mixture of micro-silica and silica flour.  
     
     
         4 . The suspension of  claim 1  wherein said silica is present in said suspension in an amount in the range of from about 50% to about 250% by weight of said water in said suspension.  
     
     
         5 . The suspension of  claim 1  wherein said suspending agent is a colloidal material selected from the group consisting of carbon black, lignite, brown coal, humic acid, styrene-butadiene rubber latexes, polyvinyl alcohol latexes, acetate latexes, acrylate latexes, precipitated silica and pyrogenic silica.  
     
     
         6 . The suspension of  claim 1  wherein said suspending agent is a clay selected from the group consisting of bentonite, attapulgite, kalonite, meta kalonite, hectorite and sepiolite.  
     
     
         7 . The suspension of  claim 1  wherein said suspending agent is a polymer selected from the group consisting of a copolymer of 2-acrylamido-2-methylpropane sulfonic acid and N,N-dimethylacrylamide, carragenan, scleroglucan, xanthan gum, guar gum, hydroxyethylcellulose, carboxymethylhydroxyethylcellulose, hydroxypropylguar, welan gum, acrylic acid copolymers and terpolymers and vinyl acetate copolymers and terpolymers.  
     
     
         8 . The suspension of  claim 1  wherein said suspending agent is present in said suspension in an amount in the range of from about 0.1% to about 100% by weight of said water in said suspension.  
     
     
         9 . A storable water-silica suspension for use in well cement compositions comprising: 
 water;    silica; and    an effective amount of a suspending agent selected from the group consisting of colloidal materials, clays and gel forming polymers.    
     
     
         10 . The suspension of  claim 9  wherein said water is selected from the group consisting of fresh water and salt water.  
     
     
         11 . The suspension of  claim 9  wherein said silica is selected from the group consisting of fine silica flour, silica flour, sand and mixtures thereof.  
     
     
         12 . The suspension of  claim 9  wherein said silica is present in said suspension in an amount in the range of from about 50% to about 250% by weight of said water in said suspension.  
     
     
         13 . The suspension of  claim 9  wherein said suspending agent is a colloidal material selected from the group consisting of carbon black, lignite, brown coal, humic acid, styrene-butadiene rubber latexes, polyvinyl alcohol latexes, acetate latexes, acrylate latexes, precipitated silica and pyrogenic silica.  
     
     
         14 . The suspension of  claim 9  wherein said suspending agent is a clay selected from the group consisting of bentonite, attapulgite, kalonite, meta kalonite, hectorite and sepiolite.  
     
     
         15 . The suspension of  claim 9  wherein said suspending agent is a polymer selected from the group consisting of a copolymer of 2-acrylamido-2-methylpropane sulfonic acid and N,N-dimethylacrylamide, carragenan, scleroglucan, xanthan gum, guar gum, hydroxyethylcellulose, carboxymethylhydroxyethylcellulose, hydroxypropylguar, welan gum, acrylic acid copolymers and terpolymers and vinyl acetate copolymers and terpolymers.  
     
     
         16 . The suspension of  claim 9  wherein said suspending agent is present in said suspension in an amount in the range of from about 0.1% to about 100% by weight of said water in said suspension.  
     
     
         17 . A storable water-silica suspension for use in well cement compositions comprising: 
 water;    silica selected from the group consisting of fine silica flour, silica flour, sand and mixtures thereof present in said suspension in an amount in the range of from about 50% to about 250% by weight of water therein; and    a colloidal suspending agent selected from the group consisting of carbon black, lignite, brown coal, humic acid, styrene-butadiene rubber latexes, polyvinyl alcohol latexes, acetate latexes, acrylate latexes, precipitated silica and pyrogenic silica present in said suspension in an amount in the range of from about 25% to about 100% by weight of water therein.    
     
     
         18 . The suspension of  claim 17  wherein said water is selected from the group consisting of fresh water and salt water.  
     
     
         19 . A storable water-silica suspension for use in well cement compositions comprising: 
 water;    silica selected from the group consisting of fine silica flour, silica flour, sand and mixtures thereof present in said suspension in an amount in the range of from about 50% to about 250% by weight of water therein; and    a clay suspending agent selected from the group consisting of bentonite, attapulgite, kalonite, meta kalonite, hectorite and sepiolite present in said suspension in an amount in the range of from about 0.5% to about 8% by weight of water therein.    
     
     
         20 . The suspension of  claim 19  wherein said water is selected from the group consisting of fresh water and salt water.  
     
     
         21 . A storable water-silica suspension for use in well cement compositions comprising: 
 water;    silica selected from the group consisting of fine silica flour, silica flour, sand and mixtures thereof present in said suspension in an amount in the range of from about 50% to about 250% by weight of water therein; and    a polymer suspending agent selected from the group consisting of a copolymer of 2-acrylamido-2-methylpropane sulfonic acid and N,N-dimethylacrylamide, carragenan, scleroglucan, xanthan gum, guar gum, hydroxyethylcellulose, carboxymethylhydroxyethylcellulose, hydroxypropylguar, welan gum, acrylic acid copolymers and terpolymers and vinyl acetate copolymers and terpolymers present in said suspension in an amount in the range of from about 0.1% to about 3% by weight of water therein.    
     
     
         22 . The suspension of  claim 21  wherein said water is selected from the group consisting of fresh water and salt water.  
     
     
         23 . A method of cementing a well bore comprising the steps of: 
 (a) storing a water-silica suspension for preventing cement strength retrogression comprised of water, silica and an effective amount of a suspending agent selected from the group of colloidal materials, clays and gel forming polymers;    (b) combining said water-silica suspension with a cement composition comprised of a hydraulic cement and water;    (c) introducing said cement composition including said water-silica suspension into said well bore; and    (d) allowing said cement composition to set.    
     
     
         24 . The method of  claim 23  wherein said water in said suspension is selected from the group consisting of fresh water and salt water.  
     
     
         25 . The method of  claim 23  wherein said silica in said suspension is selected from the group consisting of fine silica flour, silica flour, sand and mixtures thereof.  
     
     
         26 . The method of  claim 23  wherein said silica is present in said suspension in an amount in the range of from about 50% to about 250% by weight of said water in said suspension.  
     
     
         27 . The method of  claim 23  wherein said suspending agent in said suspension is a colloidal material selected from the group consisting of carbon black, lignite, brown coal, humic acid, styrene-butadiene rubber latexes, polyvinyl alcohol latexes, acetate latexes, acrylate latexes, precipitated silica and pyrogenic silica.  
     
     
         28 . The method of  claim 23  wherein said suspending agent in said suspension is a clay selected from the group consisting of bentonite, attapulgite, kalonite, meta kalonite, hectorite and sepiolite.  
     
     
         29 . The method of  claim 23  wherein said suspending agent in said suspension is a polymer selected from the group consisting of a copolymer of 2-acrylamido-2-methylpropane sulfonic acid and N,N-dimethylacrylamide, carragenan, scleroglucan, xanthan gum, guar gum, hydroxyethylcellulose, carboxymethylhydroxyethylcellulose, hydroxypropylguar, welan gum, acrylic acid copolymers and terpolymers and vinyl acetate copolymers and terpolymers.  
     
     
         30 . The method of  claim 23  wherein said suspending agent in said suspension is present therein in an amount in the range of from about 0.1% to about 100% by weight of said water in said suspension.  
     
     
         31 . A method of cementing a well bore comprising the steps of: 
 (a) storing a water-silica suspension for preventing cement strength retrogression comprised of water, silica selected from the group consisting of fine silica flour, silica flour, sand and mixtures thereof present in said suspension in an amount in the range of from about 50% to about 250% by weight of water therein and a colloidal suspending agent selected from the group consisting of carbon black, lignite, brown coal, humic acid, styrene-butadiene rubber latexes, polyvinyl alcohol latexes, acetate latexes, acrylate latexes, precipitated silica and pyrogenic silica present in said suspension in an amount in the range of from about 50% to about 100% by weight of water therein;    (b) combining said water-silica suspension with a cement composition comprised of a hydraulic cement and water;    (c) introducing said cement composition including said water-silica suspension into said well bore; and    (d) allowing said cement composition to set.    
     
     
         32 . The method of  claim 31  wherein said water in said suspension is selected from the group consisting of fresh water and salt water.  
     
     
         33 . The method of  claim 31  wherein said colloidal suspending agent is carbon black.  
     
     
         34 . A method of cementing in a well bore comprising the steps of: 
 (a) storing a water-silica suspension for preventing cement strength retrogression comprised of water, silica selected from the group consisting of fine silica flour, silica flour, sand and mixtures thereof present in said suspension in an amount in the range of from about 50% to about 250% by weight of water therein and a clay suspending agent selected from the group consisting of bentonite, attapulgite, kalonite, meta kalonite, hectorite and sepiolite, present in said suspension in an amount in the range of from about 0.5% to about 8% by weight of water therein;    (b) combining said water-silica suspension with a cement composition comprised of a hydraulic cement and water;    (c) introducing said cement composition including said water-silica suspension into said well bore; and    (d) allowing said cement composition to set.    
     
     
         35 . The method of  claim 34  wherein said water in said suspension is selected from the group consisting of fresh water and salt water.  
     
     
         36 . The method of  claim 34  wherein said clay suspending agent is bentonite.  
     
     
         37 . A method of cementing in a well bore comprising the steps of: 
 (a) storing a water-silica suspension for preventing cement strength retrogression comprised of water, silica selected from the group consisting of fine silica flour, silica flour, sand and mixtures thereof present in said suspension in an amount in the range of from about 50% to about 250% by weight of water therein and a polymer suspending agent selected from the group consisting of a copolymer of 2-acrylamido-2-methylpropane sulfonic acid and N,N-dimethylacrylamide, carragenan, scleroglucan, xanthan gum, guar gum, hydroxyethylcellulose, carboxymethylhydroxyethylcellulose, hydroxypropylguar, welan gum, acrylic acid copolymers and terpolymers and vinyl acetate copolymers and terpolymers present in said suspension in an amount in the range of from about 0.1% to about 3% by weight of water therein;    (b) combining said water-silica suspension with a cement composition comprised of a hydraulic cement and water;    (c) introducing said cement composition including said water-silica suspension into said well bore; and    (d) allowing said cement composition to set.    
     
     
         38 . The method of  claim 37  wherein said water in said suspension is selected from the group consisting of fresh water and salt water.  
     
     
         39 . The method of  claim 37  wherein said polymer suspending agent is a copolymer of 2-acrylamido-2-methylpropane sulfonic acid and N,N-dimethylacrylamide.