Surfactant based compositions and process for heavy oil recovery

Abstract

A process for recovering heavy oil with the steps of: a) injecting into one or more injection wells an aqueous injection fluid containing one or more surfactants designed to form a pseudo-emulsion between the injection fluid and the heavy oil, and, b) recovering the oil from one or more producing wells. The process does not require the addition of outside mechanical or thermal energy or solvents to recover the heavy oil and does not form emulsions between the injection fluid and the heavy oil that may be difficult to break when brought to the surface or may cause increased viscosity and injectivity problems within the reservoir.

1 . A process for recovering heavy oil by
 a) injecting an aqueous injection fluid containing one or more surfactants into one or more injection wells to form a low viscosity water external pseudo-emulsion when contacting the heavy oil; and   b) recovering the oil from one or more producing wells.   
     
     
         2 . The process of recovering heavy oil of  claim 1  where the aqueous injection fluid contains in addition to the surfactants, one or more from the group:
 viscosifiers for mobility control, alkalis for reducing adsorption, co-surfactants for improved interfacial tension lowering, cosolvents for improved handling, freeze-thaw stability.   
     
     
         3 . The process of recovering heavy oil of  claim 1  where the injection wells and producing wells are the same well. 
     
     
         4 . The process of recovering heavy oil of  claim 1  where the injection wells and the producing wells are different wells. 
     
     
         5 . The process for the recovery of heavy oil of  claim 1  where the one or more surfactants are chosen from the group: anionic surfactants, nonionic surfactants. 
     
     
         6 . The process for the recovery of heavy oil of  claim 1  where the one or more surfactants are chosen from the group alkoxylated phenol, alkoxylated alkylphenols, alkoxylated linear or branched alcohols, alkoxylated fatty acids, alkoxylated sorbitol esters, 
     
     
         7 . The process for the recovery of heavy oil of  claim 1  where the one or more surfactants are chosen from the group the phosphate, sulfonate, and sulfate alkali metal salts of the phosphate esters of alkoxylated phenol, alkoxylated alkylphenols, alkoxylated linear or branched alcohols. 
     
     
         8 . The process for the recovery of heavy oil of  claim 1  where the one or more surfactants are chosen from the group, alkali metal salts of branched or linear alkylaryl sulfonates, branched or linear alkyl ether sulfonates, branched or linear internal olefin sulfonates, branched or linear alpha olefin sulfonates. 
     
     
         9 . The process for the recovery of heavy oil of  claim 1  where the one or more surfactants are chosen from the group sulfonated alkali metal salts of alkoxylated phenol, alkoxylated alkylphenols, alkoxylated linear or branched alcohols. 
     
     
         10 . The process for the recovery of heavy oil of  claim 1  where the one or more surfactants are chosen from the group the sulfate esters of alkali metal salts of alkoxylated phenol, alkoxylated alkylphenols, alkoxylated linear or branched alcohols. 
     
     
         11 . The process for the recovery of heavy oil of  claim 1  where the one or more surfactants have the structure 
       
         
           
           
               
               
           
         
       
       where
 m+n=5-28 
 M=H, Na, K, NH 3 , Amine, Ca, Mg, 
 Y=H or COOM or PO 3 M 
 X=H, CH 3  or CH 2 CH 3    
 x=1-30 or more. 
 
     
     
         12 . The process for the recovery of heavy oil described in  claim 1  where the one or more surfactants has the structure I or II 
       
         
           
           
               
               
           
         
       
       where;
 M is Na, K, NH 3 , Ca, Mg, or an amine 
 a=0 to 20 
 b=0 to 20 
 x+y+z=5 to 19. 
 
     
     
         13 . The process for the recovery of heavy oil described in  claim 1  where the one or more surfactants have the structure
   R 1 [—(O—(R 2 O) m —(R 3 O) n —(R 4 )] y      
       where:
 R 1 =alkyl, alkenyl, amine, alkylamine, dialkylamine, trialkylamine, aromatic, polyaromatic, cycloalkane, cycloalkene, 
 R 2 =C 2 H 4  or C 3 H 6  or C 4 H 
 R 3 =C 2 H 4  or C 3 H 6  or C 4 H 8 , 
 R 4 =linear or branched C 7 H 14 SO 3 X to C 30 H 60 SO 3 X when y=1, 
 R 4 =linear or branched C 7 H 14 SO 3 X to C 30 H 60 SO 3 X or H when y>1 but at least one R 4  must be linear or branched C 7 H 14 SO 3 X to C 30 H 60 SO 3 X,
 m≧1, 
 n≧0, 
 n+m=1 to 30+, 
 y≧1, 
 X=alkali metal or alkaline earth metal or ammonium or amine. 
 
 
     
     
         14 . The process for the recovery of heavy oil of  claim 1  where the one or more surfactants are present in the aqueous injection fluid at concentrations between 0.025 and 5.0 wt %. 
     
     
         15 . The process for the recovery of heavy oil of  claim 1  where the concentration of the one or more surfactants is chosen to provide a pseudo-emulsion without forming a stable emulsion between the injected aqueous fluid and the heavy oil.