Carbon dioxide-resistant portland based cement composition

Abstract

The invention provides a carbon dioxide-resistant hydraulic cement composition. The inventive composition comprises a Portland cement, Class C fly ash and water. The Class C fly ash is present in the composition in an amount in the range of from about 5% to less than about 30% by weight based on the total weight of the cementitious components in the composition. In another aspect, the invention provides a method of cementing in a carbon dioxide environment. In yet another aspect, the invention provides a method of enhancing the recovery of a hydrocarbon fluid from a subterranean formation.

What is claimed is: 
     
         1 . A carbon dioxide-resistant hydraulic cement composition, comprising:
 a Portland cement;   Class C fly ash present in an amount in the range of from about 5% to less than about 30% by weight based on the total weight of the cementitious components in said composition; and   water present in an amount sufficient to form a slurry.   
     
     
         2 . The carbon dioxide-resistant hydraulic cement composition of  claim 1 , wherein said Portland cement is selected from API Class G type Portland cement and API Class H type Portland cement. 
     
     
         3 . The carbon dioxide-resistant hydraulic cement composition of  claim 2 , wherein said Portland cement is API Class H type Portland cement. 
     
     
         4 . The carbon dioxide-resistant hydraulic cement composition of  claim 1 , further comprising a fluid loss additive. 
     
     
         5 . The carbon dioxide-resistant hydraulic cement composition of  claim 1 , further comprising a defoamer. 
     
     
         6 . The carbon dioxide-resistant hydraulic cement composition of  claim 1 , wherein said Class C fly ash is present in said composition in an amount in the range of from about 15% to about 28% by weight based on the total weight of the cementitious components in said composition. 
     
     
         7 . The carbon dioxide-resistant hydraulic cement composition of  claim 6 , wherein said Class C fly ash is present in said composition in an amount of about 25% by weight based on the total weight of the cementitious components in said composition. 
     
     
         8 . The carbon dioxide-resistant hydraulic cement composition of  claim 1 , wherein said Class C fly ash is present in said composition in an amount of from about 5% to less than about 30% by weight based on the total weight of said Portland cement and Class C fly ash in said composition. 
     
     
         9 . The carbon dioxide-resistant hydraulic cement composition of  claim 1 , wherein said composition has a cement density in the range of from about 12 to about 19 pounds of cementitious components per gallon of water in said slurry. 
     
     
         10 . The carbon dioxide-resistant hydraulic cement composition of  claim 1 , wherein after said composition has set, said composition has a cement penetration of 1 mm or less after 15 days of carbon dioxide exposure. 
     
     
         11 . The carbon dioxide-resistant hydraulic cement composition of  claim 1 , wherein after said composition has set, said composition has a cement penetration of 1 mm or less at 30 days. 
     
     
         12 . A carbon dioxide-resistant hydraulic cement composition, comprising:
 a Portland cement;   Class C fly ash present in an amount in the range of from 5% to less than 30% by weight based on the total weight of the cementitious components in said composition; and   water present in an amount sufficient to form a slurry.   
     
     
         13 . The carbon dioxide-resistant hydraulic cement composition of  claim 12 , wherein said Portland cement is selected from API Class G type Portland cement and API Class H type Portland cement. 
     
     
         14 . The carbon dioxide-resistant hydraulic cement composition of  claim 13 , wherein said Portland cement is API Class H type Portland cement. 
     
     
         15 . The carbon dioxide-resistant hydraulic cement composition of  claim 12 , further comprising a fluid loss additive. 
     
     
         16 . The carbon dioxide-resistant hydraulic cement composition of  claim 12 , further comprising a defoamer. 
     
     
         17 . The carbon dioxide-resistant hydraulic cement composition of  claim 12 , wherein said Class C fly ash is present in said composition in an amount in the range of from 15% to 28% by weight based on the total weight of the cementitious components in said composition. 
     
     
         18 . The carbon dioxide-resistant hydraulic cement composition of  claim 12 , wherein said Class C fly ash is present in said composition in an amount of from 5% to less than 30% by weight based on the total weight of said Portland cement and Class C fly ash in said composition. 
     
     
         19 . The carbon dioxide-resistant hydraulic cement composition of  claim 12 , wherein said composition has a cement density in the range of from 12 to 19 pounds of cementitious components per gallon of water in said slurry. 
     
     
         20 . The carbon dioxide-resistant hydraulic cement composition of  claim 13 , wherein said Portland cement is API Class H type Portland cement, and said Class C fly ash is present in said composition in an amount in the range of from 15% to 28% by weight based on the total weight of the cementitious components in said composition, said composition further comprising:
 a fluid loss additive; and   a defoamer, and wherein after said composition has set, said composition has a cement penetration of 1 mm or less at 30 days.