Methods of cementing in subterranean zones and cementing compositions therefor

Abstract

A method and cementing composition is provided for sealing a subterranean zone penetrated by a well bore, wherein the cementing composition comprises a mixture of cementitious material, a polymeric cement cohesion additive, and sufficient water to form a slurry. The polymeric cement cohesion additive is a high molecular weight hydroxyethylcellulose. The method comprises placing the cement composition in the subterranean zone and allowing the cement composition to set into a solid mass therein.

1 . A cementing composition for sealing a subterranean zone comprising: cement; an effective amount of a polymeric cement cohesion additive sufficient to inhibit one or both of contamination and dilution of the cementing composition by fluids in the subterranean zone; and water.  
   
   
       2 . The composition of  claim 1  wherein the polymeric cement cohesion additive comprises hydroxyethylcellulose.  
   
   
       3 . The composition of  claim 2  wherein the hydroxyethylcellulose has a molecular weight of at least 300,000 g/mol.  
   
   
       4 . The composition of  claim 2  wherein the hydroxyethylcellulose has a molecular weight of at least 1,300,000 g/mol.  
   
   
       5 . The composition of  claim 2  wherein the hydroxyethylcellulose comprises a mixture of hydroxyethylcellulose having a molecular weight of at least 1,300,000 g/mol. and hydroxyethylcellulose having a molecular weight of at least 300,000 g/mol.  
   
   
       6 . The composition of  claim 3  wherein the composition comprises at least about 0.45 percent of hydroxyethylcellulose by weight of the cement.  
   
   
       7 . The composition of  claim 4  wherein the composition comprises at least about 0.2 percent of hydroxyethylcellulose by weight of the cement.  
   
   
       8 . The composition of  claim 5  wherein the composition comprises at least about 0.3 percent of hydroxyethylcellulose by weight of the cement.  
   
   
       9 . The composition of  claim 1  wherein the cement is Portland cement, pozzolan cement, gypsum cement, aluminous cement, silica cement, or alkaline cement.  
   
   
       10 . The composition of  claim 9  wherein the cement is class A, G or H Portland cement.  
   
   
       11 . The composition of  claim 1  wherein the water is present in a range of 35-65 percent by weight of the cement.  
   
   
       12 . The composition of  claim 1  further comprising a mixture of foaming and foam stabilizing surfactants present in an amount sufficient to form and stabilize a foamed cementing composition.  
   
   
       13 . The composition of  claim 12  wherein the mixture of foaming and foam stabilizing surfactants is comprised of an ethoxylated alcohol ether sulfate present in an amount of about 63.3 parts by weight, cocoylamidopropylbetaine present in an amount of about 31.7 parts by weight and cocoylamidopropyldimethylamine oxide present in an amount of about 5 parts by weight.  
   
   
       14 . The composition of  claim 13  wherein the mixture of foaming and foam stabilizing surfactants in a 30% to 50% aqueous solution is present in an amount in the range of from about 1% to about 3% by volume of water therein.  
   
   
       15 . The composition of  claim 12  wherein the cementing composition further comprises sufficient gas to form a foam.  
   
   
       16 . The composition of  claim 15  wherein the gas is selected from the group consisting of air and nitrogen.  
   
   
       17 . The composition of  claim 16  wherein the gas is present in the composition in an amount in the range of from about 15% to about 30% by volume of the composition.  
   
   
       18 . The composition of  claim 1  further comprising one or more of a slurry density modifying material, dispersing agent, set retarding agent, set accelerating agent, fluid loss control agent, strength retrogression control agent, viscosifying agent, foaming agent, and foam stabilizing agent.  
   
   
       19 . A cementing composition for sealing a subterranean zone comprising: 
 at least one hydraulic cement selected from the group consisting of Portland cement, pozzolan cement, gypsum cement, aluminous cement, silica cement and alkaline cement;    an effective amount of a polymeric cement cohesion additive comprising hydroxyethylcellulose sufficient to inhibit one or both of contamination and dilution of the cementing composition by fluids in the subterranean zone;    water in an amount of from 35 to 65 percent by weight of the cement; and    one or more additive selected from the group consisting of a slurry density modifying material, a dispersing agent, a set retarding agent, a set accelerating agent, a fluid loss control agent, a strength retrogression control agent, a viscosifying agent, a foaming agent, and a foam stabilizing agent.    
   
   
       20 . A cementing composition for sealing a subterranean zone comprising: 
 at least one hydraulic cement selected from the group consisting of Portland cement, pozzolan cement, gypsum cement, aluminous cement, silica cement and alkaline cement;    an effective amount of a polymeric cement cohesion additive comprising hydroxyethylcellulose sufficient to inhibit one or both of contamination and dilution of the cementing composition by fluids in the subterranean zone;    water in an amount of from 35 to 65 percent by weight of the cement; and    a mixture of foaming and foam stabilizing surfactants present in an amount sufficient to form and stabilize a foamed cementing composition.