Methods of using stable hydrocarbon foams

Abstract

A method of treating a subterranean geological formation comprising hydrocarbons comprising injecting a foam into the formation at a rate and pressure sufficient to open at least one fracture therein and a method of completing a well in a subterranean geological formation penetrated by a well bore comprising introducing a foam into the well bore of the subterranean geological formation and carrying out a completion operation in the well bore of the subterranean geological formation. The foam comprises a liquid hydrocarbon and a nonionic polymeric surfactant comprising fluorinated repeating units, wherein the fluorinated repeating units have up to 5 perfluorinated carbon atoms, and wherein a one weight percent solution of the nonionic polymeric surfactant in kerosene has a foam half-life at 22° C. of at least 10 minutes.

1 . A method of completing a well in a subterranean geological formation penetrated by a well bore, the method comprising:
 providing a foam comprising a liquid hydrocarbon and a nonionic polymeric surfactant comprising fluorinated repeating units, wherein the fluorinated repeating units have up to 5 perfluorinated carbon atoms, and wherein a one weight percent solution of the nonionic polymeric surfactant in kerosene has a foam half-life at 22° C. of at least 10 minutes;   introducing the foam into the well bore of the subterranean geological formation; and   carrying out a completion operation in the well bore of the subterranean geological formation.   
   
   
       2 . The method of  claim 1 , wherein the completion operation is at least one of gravel packing the well bore, cleaning the well bore, or cementing the well bore. 
   
   
       3 . The method of  claim 1 , wherein the nonionic polymeric surfactant comprises:
 at least one divalent unit represented by formula I:   
     
       
         
         
             
             
         
       
       at least one divalent unit represented by formula II: 
     
     
       
         
         
             
             
         
       
       
         wherein
 Rf is a perfluoroalkyl group having from 3 to 4 carbon atoms; 
 R and R 2  are each independently hydrogen or alkyl of 1 to 4 carbon atoms; 
 R 1  is alkyl of 16 to 24 carbon atoms; and 
 n is an integer from 2 to 11. 
 
       
     
   
   
       4 . The method of  claim 3 , wherein R 1  is alkyl of 18 to 22 carbon atoms. 
   
   
       5 . The method of  claim 3 , wherein the nonionic polymeric surfactant comprises the divalent unit represented by formula I in a range from 45 to 75 weight percent, based on the total weight of the nonionic polymeric surfactant. 
   
   
       6 . The method of  claim 3 , wherein the weight average molecular weight of the nonionic polymeric surfactant is at least 45,000 grams per mole. 
   
   
       7 . The method of  claim 1 , wherein a one weight percent solution of the nonionic polymeric surfactant in kerosene has a foam half-life at 22° C. of at least 20 minutes. 
   
   
       8 . The method of  claim 1 , wherein the nonionic polymeric surfactant is present in a range from 0.1 percent to 5 percent by weight, based on total weight of the foam. 
   
   
       9 . The method of  claim 1 , wherein the liquid hydrocarbon is at least one of kerosene, diesel, gasoline, pentane, hexane, heptane, mineral oil, or a naphthene. 
   
   
       10 . The method of  claim 1 , wherein the foam further comprises a plurality of gravel particles. 
   
   
       11 . A method of making a nonionic polymeric surfactant, the method comprising:
 combining components comprising:
 at least one compound represented by formula: 
   
     
       
         
         
             
             
         
       
       
         at least one compound represented by formula: 
       
     
     
       
         
         
             
             
         
       
       
         
           wherein 
           Rf is independently a perfluoroalkyl group having from 3 to 4 carbon atoms; 
           R and R 2  are each independently hydrogen or alkyl of 1 to 4 carbon atoms; 
           R 1  is independently alkyl of 16 to 24 carbon atoms; and 
           n is independently an integer from 2 to 11, 
         
         a chain-transfer agent, 
         a free-radical initiator, and 
         a solvent; and 
       
       heating the components at a temperature of up to 70° C. 
     
   
   
       12 . A method of treating a subterranean geological formation bearing hydrocarbons, the method comprising:
 injecting a foam into a subterranean geological formation bearing hydrocarbons at a rate and pressure sufficient to open at least one fracture therein, wherein the foam comprises a liquid hydrocarbon and a nonionic polymeric surfactant comprising fluorinated repeating units, wherein the fluorinated repeating units have up to 5 perfluorinated carbon atoms, and wherein a one weight percent solution of the nonionic polymeric surfactant in kerosene has a foam half-life at 22° C. of at least 10 minutes.   
   
   
       13 . The method of  claim 12 , wherein the nonionic polymeric surfactant comprises:
 at least one divalent unit represented by formula I:   
     
       
         
         
             
             
         
       
       at least one divalent unit represented by formula II: 
     
     
       
         
         
             
             
         
       
       
         wherein
 Rf is a perfluoroalkyl group having from 3 to 4 carbon atoms; 
 R and R 2  are each independently hydrogen or alkyl of 1 to 4 carbon atoms; 
 R 1  is alkyl of 16 to 24 carbon atoms; and 
 n is an integer from 2 to 11. 
 
       
     
   
   
       14 . The method of  claim 13 , wherein R 1  is alkyl of 18 to 22 carbon atoms. 
   
   
       15 . The method of  claim 13 , wherein the nonionic polymeric surfactant comprises the divalent unit represented by formula I in a range from 45 to 75 weight percent, based on the total weight of the nonionic polymeric surfactant. 
   
   
       16 . The method of  claim 13 , wherein the weight average molecular weight of the nonionic polymeric surfactant is at least 45,000 grams per mole. 
   
   
       17 . The method of  claim 12 , wherein the liquid hydrocarbon is at least one of kerosene, diesel, gasoline, pentane, hexane, heptane, mineral oil, or a naphthene. 
   
   
       18 . The method of  claim 12 , wherein a one weight percent solution of the nonionic polymeric surfactant in kerosene has a foam half-life at 22° C. of at least 20 minutes. 
   
   
       19 . The method of  claim 12 , further comprising injecting a plurality of proppant particles into the fracture. 
   
   
       20 . The method of  claim 19 , wherein the foam further comprises a gelling agent.