Di-functional anionic surfactants for enhanced oil recovery

Abstract

The present invention describes the synthesis and use of cleavable di-functional anionic surfactants for enhanced oil recovery applications and/or the use of sacrificial surfactants.

What is claimed is: 
     
         1 . A method of synthesizing a di-functional anionic surfactant of formula (I) comprising: 
       
         
           
           
               
               
           
         
         (a) deriving an acid treated intermediate cyclic sultone using a process that comprises sulfonating a solution of an internal olefin, wherein
 (i) the internal olefin has a general formula R 1 —C 4 H 6 —R 2 , 
 (ii) R 1  and R 2  are the same or different, 
 (iii) R 1  and R 2  are each an alkyl group or hydrogen, and 
 (iv) R 1  and R 2  combined comprise 10 to 40 carbon atoms; 
 
         (b) neutralizing and hydrolyzing the acid treated intermediate cyclic sultone to yield the di-functional anionic surfactant of formula (I); and 
         (c) recovering the di-functional anionic surfactant of formula (I) from the reaction mixture. 
       
     
     
         2 . The method of  claim 1 , wherein said deriving the acid treated intermediate cyclic sultone comprises:
 (i) sulfonating the solution of the internal olefin with sulfur trioxide in air to derive an intermediate cyclic sultone, and   (ii) treating the intermediate cyclic sultone with an acid.   
     
     
         3 . The method of  claim 1 , wherein said deriving the acid treated intermediate cyclic sultone comprises sulfonating the solution of the internal olefin with a sulfating mixture of sulfuric acid and sulfur trioxide to derive the acid treated intermediate cyclic sultone. 
     
     
         4 . A method of synthesizing a di-functional anionic of formula (II), comprising: 
       
         
           
           
               
               
           
         
         (a) alkoylating a dinonylphenol to yield an intermediate alkoxylate derivative; wherein the step of alkoxylating is performed using ethylene oxide, propylene oxide, or a mixture of both; 
         (b) treating the intermediate alkoyxlate derivative with a sulfur trioxide in air to form an intermediate sulfonated alkoxylate derivative; 
         (c) neutralizing and hydrolyzing the intermediate sulfonated alkoxylate derivative with a base to yield the di-functional anionic surfactant of formula (II); and 
         (d) recovering the di-functional anionic surfactant of formula (II) from the reaction mixture, wherein
 (i) R 1  and R 2  are the same or different, 
 (ii) R 1  and R 2  are each an alkyl group or hydrogen, and 
 (iii) R 1  and R 2  combined comprise 10 to 40 carbon atoms. 
 
       
     
     
         5 . A composition suitable for treating a hydrocarbon-bearing formation, said composition comprising a cleavable di-functional anionic surfactant, wherein
 (a) the di-functional anionic surfactant is sufficiently soluble in water such that the di-functional anionic surfactant is suitable for injection into the hydrocarbon-bearing formation, and   (b) the di-functional anionic surfactant is suitable for operation in the hydrocarbon-bearing formation such that the di-functional anionic surfactant is
 (i) cleavable, and 
 (ii) suitable to release a highly surface active monofunctional sulfonate in the hydrocarbon bearing formation. 
   
     
     
         6 . The composition of  claim 5 , wherein the composition further comprises a sacrificial surfactant. 
     
     
         7 . The composition of  claim 5 , wherein the di-functional anionic surfactant is of the formula (I): 
       
         
           
           
               
               
           
         
         wherein
 (a) R 1  and R 2  are the same or different, 
 (b) R 1  and R 2  are each an alkyl group or a hydrogen, and 
 (c) R 1  and R 2  combined comprise 10 to 40 carbon atoms. 
 
       
     
     
         8 . The composition of  claim 5 , wherein the di-functional anionic surfactant is of the formula (II): 
       
         
           
           
               
               
           
         
         wherein
 (a) R 1  and R 2  are the same or different, 
 (b) R 1  and R 2  are each an alkyl group or a hydrogen, and 
 (c) R 1  and R 2  combined comprise 10 to 40 carbon atoms. 
 
       
     
     
         9 . The composition of  claim 5 , wherein
 (a) the composition comprises a sacrificial surfactant,   (b) the di-functional anionic surfactant selected from the group consisting of a di-functional anionic surfactant of formula (I), a di-functional anionic surfactant of formula (II), and combinations thereof, and   (c) formula (I) and formula (II) are, respectively:   
       
         
           
           
               
               
           
         
       
     
     
         10 . The composition of  claim 9 , wherein the sacrificial surfactant is selected from the group consisting of dialkyl sulfosuccinates and their alkoxylated homologues, monoalkyl sulfosuccinates and their alkoxylated versions, mono alkyl succinates and their alkoxylated versions, alcohol alkoxysulfates, and combinations thereof, wherein the dialkyl sulfosuccinates, monoalkyl sulfosuccinates, and mono alkyl succinates comprise linear or branched C 4 -C 16  saturated or unsaturated chains, polyethoxy or polypropoxy chains with a degree of polymerization ranging from 0-12, C 4 -C 12  alkylphenol structures or combinations thereof. 
     
     
         11 . The composition of  claim 10 , wherein the alcohol alkoxysulfates comprise linear or branched C 6 -C 32  chains, polyethoxy or polypropoxy chains with a degree of polymerization ranging from 0-50, C 4 -C 12  alkylphenol structures or combinations thereof. 
     
     
         12 . The composition of  claim 5 , wherein the composition comprises a high molecular weight sulfated internal olefin sulfonate or a high molecular weight Dialkylphenol alkoxylate sulfonate sulfate. 
     
     
         13 . The composition of  claim 9 , wherein the sacrificial surfactant is hydrolyzable and suitable for forming an alcohol under conditions in the hydrocarbon-bearing formation. 
     
     
         14 . A composition suitable for treating a hydrocarbon-bearing formation wherein the composition comprises a first surfactant and a sacrificial surfactant, wherein the sacrificial surfactant in the composition is suitable for causing the first surfactant to become sufficiently soluble in water for injection into a hydrocarbon-bearing formation. 
     
     
         15 . The composition of  claim 14 , wherein the sacrificial surfactant is selected from the group consisting of dialkyl sulfosuccinates and their alkoxylated homologues, mono alkyl sulfosuccinates and their alkoxylated versions, monoalkyl succinates, monoalkyl maleates and their alkoxylated versions, and alcohol alkoxysulfates.