Flooding operations employing chlorine dioxide

Abstract

A method includes introducing a treatment fluid including a first polymer gel into a subterranean formation to generate a production fluid having an aqueous portion and a hydrocarbon portion, treating the aqueous portion of the production fluid with chlorine dioxide to separate additional hydrocarbons from the aqueous portion, and adjusting the viscosity of the treated aqueous portion prior to introducing the treated aqueous portion back into the subterranean formation.

What is claimed is: 
     
         1 . A method comprising:
 introducing a polymer gel-containing treatment fluid into a subterranean formation, the polymer gel-containing treatment fluid comprising:
 a water-soluble polymer; 
 an amount of chlorine dioxide sufficient to increase the viscosity of the treatment fluid; and 
 an aqueous base fluid. 
   
     
     
         2 . The method of  claim 1 , wherein the amount of chlorine dioxide is at least about 5 ppm residual chlorine dioxide. 
     
     
         3 . The method of  claim 1 , wherein the amount of chlorine dioxide comprises at least about 6 ppm residual chlorine dioxide. 
     
     
         4 . The method of  claim 1 , wherein the amount of chlorine dioxide is in a range from about 5 ppm to about 20 ppm residual chlorine dioxide. 
     
     
         5 . The method of  claim 1 , wherein an upper limit of the amount chlorine dioxide is an amount less than would substantially break the polymer gel, as determined by viscosity measurement. 
     
     
         6 . The method of  claim 1 , wherein the amount of chlorine dioxide is substantially greater than needed for biocidal activity. 
     
     
         7 . A method comprising:
 introducing a treatment fluid into a subterranean formation, the treatment fluid comprising:
 a polymer gel comprising a water-soluble polymer; and 
 an amount of chlorine dioxide substantially greater than needed for biocidal activity and also allowing an amount of water-soluble polymer to be used to form the polymer gel to be reduced by about 25% to about 75%, relative to a treatment fluid lacking chlorine dioxide; and 
 an aqueous base fluid. 
   
     
     
         8 . The method of  claim 7 , wherein the amount of chlorine dioxide comprises at least about 5 ppm residual chlorine dioxide. 
     
     
         9 . The method of  claim 7 , wherein the amount of chlorine dioxide comprises at least about 6 ppm residual chlorine dioxide. 
     
     
         10 . The method of  claim 7 , wherein the amount of chlorine dioxides comprises from about 5 ppm to about 20 ppm residual chlorine dioxide. 
     
     
         11 . The method of  claim 7 , wherein an upper limit of the amount of chlorine dioxide is an amount less than substantially breaks the polymer gel, as determined by measurement of viscosity.