Oil recovery method using alkali and alkylaryl sulfonate surfactants derived from broad distribution alpha-olefins

Abstract

An oil recovery process is disclosed which uses an alkali(s) and a particular class of alkylaryl sulfonate surfactants. The surfactants are derived from an alpha-olefin stream having a broad distribution of even carbon numbers ranging from 12 to 28 or more. The olefin stream is reacted with aromatic feedstock, such as benzene, toluene, xylene, ethylbenzene, or a mixture thereof to form alkylates, and then reacted with SO3 to form sulfonic acids. Alternatively, the surfactant can be formed by first reacting an alpha-olefin stream having a broad distribution of carbon numbers ranging from 12 to 28 or more with SO3 to form the olefin sulfonic acid that is subsequently used to alkylate an aromatic feedstock. The use of alkali(s) and broad distribution alpha-olefins sulfonate based surfactant has the improvements of requiring ultra-low surfactant concentrations and providing ultra-low interfacial tensions over a wide range of alkali concentrations with crude oils, especially waxy crude oil, having a broad distribution of carbon numbers.

1 . A method of recovering crude oil from a subterranean hydrocarbon containing formation which comprises (a) injecting into said formation through an injection well an aqueous solution containing an effective amount of one or more alkali(s) along with an effective amount of alkylaryl sulfonate surfactant made by alkylating and sulfonating aromatic compounds and an alpha-olefin stream having a broad distribution in olefin carbon numbers, the olefin stream is the carbon chain C 10  bottoms of a commercial ethylene synthesis alpha-olefin reactor and comprises C 10+  through C 30+  carbon chain fractions, and wherein the aromatic compound is selected from the group consisting of benzene, toluene, xylene, ethyl benzene, or mixtures thereof, and then neutralizing the resulting alkylaryl sulfonic acid, and (b) displacing said solution into the formation to recover hydrocarbons from a production well.  
   
   
       2 . The method of  claim 1  wherein said alkali is one or more selected from the group mono valent hydroxide, mono valent carbonate, mono valent silicate.  
   
   
       3 . The method according to  claim 1  wherein the alkali is selected from the group sodium hydroxide, sodium carbonate, sodium silicate.  
   
   
       4 . The method of  claim 1  where the alkali is present in amounts of from about 0.1% by weight to about 3.0% by weight.  
   
   
       5 . The method of  claim 1  where the alkylaryl sulfonate surfactant is present in amounts from about 0.025% by weight to about 0.5% by weight.  
   
   
       6 . The method of  claim 1  wherein said alpha-olefin stream is a combination of individual alpha-olefin fractions having a carbon chain of from about C 12  to about C 28 .  
   
   
       7 . The method according to  claim 1  wherein the aromatic compound is o-xylene, m-xylene, p-xylene or mixtures thereof and wherein the injection wells and production wells are selected from the group consisting of the same well, different wells or combinations thereof.  
   
   
       8 . The method of  claim 1  wherein alkylation of the aromatic compounds by the alpha-olefin stream having a broad distribution in olefin carbon numbers is conducted with AlCl 3  or HF catalyst.  
   
   
       9 . The method of  claim 1  wherein alkylation of the aromatic compounds is conducted using the olefin sulfonic acids from the sulfonation of an alpha-olefin stream having a broad distribution in olefin carbon numbers.  
   
   
       10 . The method of  claim 1  where the neutralization is carried out using NaOH.  
   
   
       11 . An alkali and alkylaryl sulfonate surfactant composition for enhanced oil recovery giving the improvement ultra-low interfacial tensions over a wide range of alkali(s) concentrations, comprising one or more alkali(s) along with an alkylaryl sulfonate wherein the alkyl chain includes C 12  to C 30+  carbon chain lengths and wherein the carbon chain is straight, branched or mixtures thereof, and wherein the aryl group is selected from the group benzene, toluene, xylene, ethyl benzene, or mixtures thereof.  
   
   
       12 . The composition of  claim 11  wherein said alkali is one or more selected from the group mono valent hydroxide, mono valent carbonate, mono valent silicate.  
   
   
       13 . The composition according to  claim 11  wherein the alkali is selected from the group sodium hydroxide, sodium carbonate, sodium silicate.  
   
   
       14 . The composition according to  claim 11  wherein the aryl group is o-xylene, m-xylene, p-xylene, or mixtures thereof.  
   
   
       15 . The composition of  claim 11  where the alkali is present in amounts of from about 0.1% by weight to about 3.0% by weight.  
   
   
       16 . The composition of  claim 11  where the alkylaryl sulfonate surfactant is present in amounts from about 0.025% by weight to about 0.5% by weight.  
   
   
       17 . The composition of  claim 11  wherein said alkyl chain is one having a carbon chain of from about C 12  to about C 28 .