Method of breaking oil-water micellar emulsions

Abstract

A method is disclosed for enhancing the separation of oil-water micellar emulsion, such as those found in production fluid. Specifically, an embodiment of the invention is separating oil and water phases in recovered production fluid by adding an ionic salt such as sodium chloride, calcium chloride, sodium carbonate, sodium bicarbonate, and/or a high-molecular weight alcohol, such as 2-ethyl hexanol or decanol, to the production fluid. The production fluid may include fluids produced from an enhanced oil recovery method.

What is claimed is: 
     
         1 . A method of separating fluids produced from a chemical enhanced oil recovery flooding process, comprising:
 a) receiving a production fluid from a chemical enhanced oil recovery flooding processes comprising an oil-water micellar emulsion;   b) adding a chemical compound to the production fluid, the chemical compound being selected from the group consisting of an ionic inorganic salt and a C 4 -C 10  alcohol; and   c) separating the production fluid to produce an oil product and a water product.   
     
     
         2 . The method of  claim 1 , wherein the oil product has a basic sediment and water content of less than 1%. 
     
     
         3 . The method of  claim 1 , wherein the water product has an oil content of less than 1000 ppm, less than 500 ppm, or less than 300 ppm. 
     
     
         4 . The method of  claim 1 , wherein the ionic organic salt is sodium chloride, calcium chloride, sodium carbonate, sodium bicarbonate, or a mixture thereof. 
     
     
         5 . The method of  claim 1 , wherein the C 4 -C 10  alcohol is 2-ethyl hexane, decanol, or a mixture thereof. 
     
     
         6 . The method of  claim 1 , further comprising mixing the production fluid and the one or more chemical compounds prior to separating the production fluid. 
     
     
         7 . The method of  claim 1 , further comprising adding a demulsifying agent to the production fluid. 
     
     
         8 . The method of  claim 1 , wherein the production fluid is separated in a wash tank. 
     
     
         9 . The method of  claim 8 , wherein the production fluid resides in the wash tank for at least 6 hours, at least 7 hours, or at least 8 hours. 
     
     
         10 . The method of  claim 1 , wherein the production fluid is separated in a pressure vessel. 
     
     
         11 . The method of  claim 1 , further comprising heating the production fluid to 100° F., at least about 125° F. at least about 150° F., at least about 175° F., at least about 200°, at least about 225° F., or at least about 250° F., or at least 275° F. 
     
     
         12 . The method of  claim 1 , wherein the added chemical compound comprises at least about 0.25%, 0.5%, about 1.0%, about 1.5%, or about 2.0% by weight of the production fluid. 
     
     
         13 . The method of  claim 1 , wherein steps a-c are performed off-shore. 
     
     
         14 . The method of  claim 1 , wherein the chemical compound is in solution. 
     
     
         15 . The method of  claim 1 , wherein the chemical compound is sodium chloride provided in the form of seawater. 
     
     
         16 . The method of  claim 15 , wherein the seawater comprises at least 0.5%, at least 0.75%, at least 1.0%, at least 1.25%, at least 1.5%, at least 1.75%, at least 2.0%, at least 2.25%, at least 2.5%, at least 2.75%, at least 3.0%, or at least 3.5% sodium chloride. 
     
     
         17 . The method of  claim 1 , wherein the chemical compound is sodium chloride provided in the form of waste brine. 
     
     
         18 . The method of  claim 17 , wherein the waste brine is waste brine from water treatment, waste brine from a boiler blow down, or waste brine from a water softener. 
     
     
         19 . The method of  claim 1 , further comprising processing the production fluid to remove a gas product. 
     
     
         20 . The method of  claim 1 , wherein the production fluid further comprises at least one of a surfactant and a polymer. 
     
     
         21 . A method of separating an oil-water micellar emulsion the method comprising:
 a) receiving a production fluid comprising an oil-water micellar emulsion;   b) adding waste brine or sea water to the production fluid; and   c) separating the production fluid to produce an oil product and a water product.   
     
     
         22 . The method of  claim 21 , wherein the waste brine is from a water treatment processes. 
     
     
         23 . The method of  claim 21 , wherein the waste brine is from a boiler blowdown. 
     
     
         24 . The method of  claim 21 , wherein the waste brine is from a water softening process.