Methods of treating a subterranean formation with a treatment fluid having surfactant effective to increase the thermal stability of the fluid

Abstract

Methods of treating a subterranean formation penetrated by a wellbore are provided, the methods comprising the steps of: (a) for a treatment fluid to be used in treating a subterranean formation, establishing a desired viscosity at a desired temperature for a desired time; (b) forming a treatment fluid that has the desired viscosity at the desired temperature for the desired time, wherein the treatment fluid comprises: (i) a base fluid; (ii) a viscosifying agent comprising a polymer; and (iii) a surfactant; and (c) introducing the treatment fluid into a subterranean formation. According to one aspect, an otherwise substantially identical treatment fluid with a lower concentration of the surfactant would not achieve the desired viscosity at the desired temperature for the desired time. According to another aspect, the polymer is at a lower concentration in the base fluid than would be required for an otherwise substantially identical treatment fluid with a lower concentration of the surfactant to achieve the desired viscosity at the desired temperature for the desired time.

1 . A method of treating a subterranean formation penetrated by a welbore, the method comprising the steps of: 
 a. for a treatment fluid to be used in treating a subterranean formation establishing a desired viscosity at a desired temperature for a desired time;    b. forming a treatment fluid that has the desired viscosity at the desired temperature for the desired time, wherein the treatment fluid comprises; 
 i. a base fluid;  
 ii. a viscosifying agent comprising a polysaccharide; and  
 iii. a surfactant;  
 wherein an otherwise substantially identical treatment fluid with a lower concentration of the surfactant would not achieve the desired viscosity at the desired temperature for the desired time; and  
   c. introducing the treatment fluid into a subterranean formation.    
     
     
         2 . The method according to  claim 1 , wherein: 
 a. the desired viscosity is at least 100 cP at a shear rate of at least 1/sec;    b. the desired temperature is at least 175° F. (80° C.); and    c. the desired time is at least 0.5 hour    
     
     
         3 . The method according to  claim 2 , wherein: 
 a. the desired viscosity is in the range of 100-5,000 cP at a shear rate in the range of 1-1,000/sec;    b. the desired temperature is in the range of 175-400° F. (80-205° C.); and    c. the desired time is in the range of about 0.5-8 hours.    
     
     
         4 . The method according to  claim 3 , wherein: 
 a. the desired viscosity is at least 500 cP at a shear rate of at least 81/sec;    b. the desired temperature is at least 220° F. (105° C.); and    c. the desired time is at least 1 hour.    
     
     
         5 . The method according to  claim 4 , wherein: 
 a. the desired viscosity is in the range of 500-2,500 cP at a shear rate of 81/sec;    b. the desired temperature is in the range of 220-300° F. (105-149° C.); and    c. the desired time is in the range of 2-4 hours.    
     
     
         6 . The method according to  claim 1 , wherein the base fluid comprises water.  
     
     
         7 . The method according to  claim 6 , wherein the viscosifying agent comprises: a water-soluble polysaccharide.  
     
     
         8 . The method according to  claim 1 , wherein an otherwise substantially identical treatment fluid without any of the surfactant would not achieve the desired viscosity at the desired temperature for the desired time.  
     
     
         9 . canceled.  
     
     
         10 . canceled.  
     
     
         11 . The method according to  claim 1 , wherein the surfactant comprises: a non-ionic surfactant.  
     
     
         12 . The method according to  claim 11 , wherein the non-ionic surfactant is selected from the group consisting of: linear ethoxylates, branched ethoxylates, linear alkyl ethoxylated alcohols, branched alkyl ethoxylated alcohols, linear propoxylates, linear alkyl propoxylated alcohols, phenol-formaldehyde non-ionic resin blends, and any combination in any proportion of the foregoing.  
     
     
         13 . The method according to  claim 1 , wherein the surfactant comprises: an anionic surfactant.  
     
     
         14 . The method according to  claim 13 , wherein the anionic surfactant is selected from the group consisting of: sulfonic acid, salt of a sulfonic acid, sulfonate, fatty acid, and salt of fatty acid, and any combination in any proportion of the foregoing.  
     
     
         15 . The method according to  claim 1 , wherein the treatment fluid further comprises: a non-surfactant thermal stabilizer.  
     
     
         16 . A method of treating a subterranean formation penetrated by a wellbore, the method comprising the steps of: 
 a. for a treatment fluid to be used in treating a subterranean formation, establishing a desired viscosity at a desired temperature for a desired time;    b. forming a treatment fluid that has the desired viscosity at the desired temperature for the desired time, wherein the treatment fluid comprises: 
 i. a base fluid;  
 ii. a viscosifying agent comprising a polysaccharide; and  
 iii. a surfactant;  
 wherein the polysaccharide is at a lower concentration in the base fluid than would be required for an otherwise substantially identical treatment fluid with a lower concentration of the surfactant to achieve the desired viscosity at the desired temperature for the desired time; and  
   c. introducing the treatment fluid into a subterranean formation.    
     
     
         17 . The method according to  claim 16 , wherein: 
 a. the desired viscosity is at least 100 cP at a shear rate of at least 1/sec;    b. the desired temperature is at least 175° F. (80° C.); and    c. the desired time is at least 0.5 hour.    
     
     
         18 . The method according to  claim 17 , wherein: 
 a. the desired viscostiy is in the range of 100-5,000 cP at a shear rate in the range of 1-1,000/sec;    b. the desired temperature is in the range of 175-400° F. (80-205° C.); and    c. the desired time is in the range of about 0.5-8 hours.    
     
     
         19 . The method according to  claim 18 , wherein: 
 a. the desired viscosity is at least 500 cP at a shear rate of at least 81/sec;    b. the desired temperature is at least 220° F. (105° C.); and    c. the desired time is at least 1 hour.    
     
     
         20 . The method according to  claim 19 , wherein: 
 a. the desired viscosity is in the range of 500-2,500 cP at a shear rate of 81/sec;    b. the desired temperature is in the range of 220-300° F. (105-149° C.); and    c. the desired time is in the range of 2-4 hours.    
     
     
         21 . The method according to  claim 16 , wherein the base fluid comprises water.  
     
     
         22 . The method according to  claim 21 , wherein the viscosifying agent comprises: a water-soluble polysaccharide.  
     
     
         23 . The method according to  claim 16 , wherein the polysaccharide is at a lower concentration in the base fluid than would be required for an otherwise substantially identical treatment fluid without any of the surfactant to achieve the desired viscosity at the desired temperature for the desired time.  
     
     
         24 . canceled.  
     
     
         25 . canceled.  
     
     
         26 . The method according to  claim 16 , wherein the surfactant comprises: a non-ionic surfactant.  
     
     
         27 . The method according to  claim 26 , wherein the non-ionic surfactant is selected from the group consisting of: linear ethoxylates, branched ethoxylates, linear alkyl ethoxylated alcohols, branched alkyl ethoxylated alcohols, linear propoxylates, linear alkyl propoxylated alcohols, phenol-formaldehyde non-ionic resin blends, and any combination in any proportion of the foregoing.  
     
     
         28 . The method according to  claim 16 , wherein the surfactant comprises: an anionic surfactant.  
     
     
         29 . The method according to  claim 28 , wherein the anionic surfactant is selected from the group consisting of: sulfonic acid, salt of a sulfonic acid, sulfonate, fatty acid, and salt of fatty acid, and any combination in any proportion of the foregoing.  
     
     
         30 . The method according to  claim 16 , wherein the treatment fluid further comprises: a non-surfactant thermal stabilizer.  
     
     
         31 . A method of treating a subterranean formation penetrated by a wellbore, the method comprising the steps of: 
 a. forming a treatment fluid comprising: 
 i. a base fluid;  
 ii. a viscosity agent comprising a polysaccharide;  
 iii. a surfactant; and  
 iv. a non-surfactant thermal stabilizer; and  
   b. introducing the treatment fluid into a subterranean formation.    
     
     
         32 . The method according to  claim 31 , wherein the base fluid comprises water.  
     
     
         33 . The method according to  claim 32 , wherein the viscosifying agent comprises: a water-soluble polysaccharide.  
     
     
         34 . The method according to  claim 32 , wherein the non-surfactant thermal stabilizer is selected from the group consisting of: thiosulfates, methanol, formate brines, and any combination thereof in any combination.