Method and apparatus for treating oil-water emulsions

Abstract

A treater for separating oil from water in an emulsion uses vertical coalescing vanes extending through the oil portion into the water portion. The vanes are made of a conductive material, and are electrically grounded in the produced water, and may be coated or partially coated to promote de-watering. Water droplets coalescing on the faces of the vanes are transported down the vane into the water portion and are removed from the system. In a further embodiment, the vanes extend above the oil portion into the gas portion to facilitate removal of gas entrained in the oil. In another embodiment, at least some of the coalescing vanes are rotatable, allowing external control of the flow of fluid through the treater.

1 . An emulsion separating apparatus comprising: 
 a first vertical coalescing vane disposed in a separation vessel so that a vertical surface of the first vertical coalescing vane extends from an oil portion into a produced water portion of the separation vessel during operation of the separation vessel, the first vertical coalescing vane having a length suitable for coalescing water from emulsion flowed past the vertical surface of the first vertical coalescing vane.    
     
     
         2 . The emulsion separating apparatus of  claim 1  further comprising a second vertical vane separated from the first vertical coalescing vane by a spacing distance, the spacing distance being not greater than one-half the length of the first vertical coalescing vane.  
     
     
         3 . The emulsion separating apparatus of  claim 2  wherein at least one of the first vertical coalescing vane and the second vertical vane is externably adjustable about a vertical axis.  
     
     
         4 . The emulsion separating apparatus of  claim 2  wherein the second vertical vane is a second vertical coalescing vane.  
     
     
         5 . The emulsion separating apparatus of  claim 2  wherein the length is between 10 inches and 12 inches.  
     
     
         6 . The emulsion separating apparatus of  claim 2  wherein the spacing distance is not greater than one-fourth the length of the vertical coalescing vane.  
     
     
         7 . The emulsion separating apparatus of  claim 2  wherein a ratio between the length and the spacing distance is 10:1.5.  
     
     
         8 . The emulsion separating apparatus of  claim 1  wherein the first vertical coalescing vane extends below an oil-water interface at least three inches.  
     
     
         9 . The emulsion separating apparatus of  claim 1  wherein the first vertical coalescing vane extends above an oil-gas interface at least two inches.  
     
     
         10 . The emulsion separating apparatus of  claim 1  further comprising a hydrophilic coating on the vertical surface of the first vertical coalescing vane.  
     
     
         11 . An emulsion separating apparatus comprising: 
 a first vertical coalescing vane disposed in a separation vessel and configured so that the first vertical coalescing vane extends below an oil-water interface into a produced water portion of the separation vessel during operation of the separation vessel, the first vertical coalescing vane having a length suitable for coalescing water from emulsion flowed past a vertical surface of the first vertical coalescing vane, the first vertical coalescing vane being externally rotatable about a vertical axis.    
     
     
         12 . The emulsion separating apparatus of  claim 11  further comprising a second vertical vane separated from the first vertical coalescing vane by a spacing distance, the spacing distance being not greater than one-half the length of the first vertical coalescing vane  
     
     
         13 . The emulsion separating apparatus of  claim 12  wherein the second vertical vane is fixed in relation to the first vertical coalescing vane.  
     
     
         14 . The emulsion separating apparatus of  claim 12  wherein the second vertical vane has a second vertical surface forming an angle of up to 45 degrees with a direction of flow of emulsion.  
     
     
         15 . A method of treating an emulsion of oil and water, the method comprising: 
 flowing the emulsion across a vertical face of a vertical coalescing vane in a treating vessel;    grounding the vertical coalescing vane in the water portion in the treating vessel;    coalescing emulsified water on a face of the vertical coalescing vane; and    conveying water down the face of the vertical coalescing vane.    
     
     
         16 . The method of  claim 15  further comprising a step of rotating the vertical coalescing vane to selectively control flow of emulsion through the treating vessel.  
     
     
         17 . The method of  claim 15  further comprising a step, prior to flowing the emulsion accross the vertical face, of treating the vertical face with a hydrophilic coating.