Apparatus and Method for Separation of Oil From Oil-Containing Produced Water

Abstract

A process for separation of oil from oil-containing produced water as well as an apparatus for separation of oil from oil-containing produced water. A perforated baffle plate is arranged in a separator tank to provide for equalizing of the downwardly flow rate of produced water. The insertion of such baffle plates has shown that less oil is following the stream downward.

1 . A method of separating oil from oil-containing produced water, the method comprising:
 mixing an oil-containing produced water with a gas-containing component to form a mixture;   feeding the mixture into a tank along an axis thereof;   spreading the mixture into the tank radially outward;   passing the mixture axially through a perforated baffle plate in the tank;   separating gas with adherent oil droplets and oil from the mixture;   allowing the oil and the gas with adherent oil droplets to rise to an outlet at the top of the tank and discharge from the tank; and   conveying cleaned produced water to an outlet at the bottom of the tank.   
     
     
         2 . The method of  claim 1 , further comprising:
 supplying the oil-containing produced water into the tank through an inlet; and   spreading the mixture into the tank using a nozzle extending from the inlet.   
     
     
         3 . The method of  claim 2 , wherein the perforated baffle plate is mounted below the nozzle within the tank. 
     
     
         4 . The method of  claim 1 , wherein the perforated baffle plate has openings, and wherein a total area of the openings is at least 15% of the area of the perforated baffle plate. 
     
     
         5 . The method of  claim 1 , wherein the perforated baffle plate extends horizontally a cross the tank. 
     
     
         6 . The method of  claim 1 , further comprising flowing the mixture along a sidewall of the tank. 
     
     
         7 . The method of  claim 6 , wherein flowing the mixture along the sidewall of the tank comprises flowing the mixture on a guide vane extending radially inward from the sidewall and between the sidewall and a shroud disposed radially inward from the sidewall. 
     
     
         8 . The method of  claim 7 , further comprising spreading the mixture into the tank radially outward a second time. 
     
     
         9 . The method of  claim 8 , wherein spreading the mixture into the tank radially outward a second time comprises flowing the mixture through an annulus chamber. 
     
     
         10 . A method, comprising:
 adding gas to an oil-containing produced water to form a mixture;   feeding the mixture into a tank along an axis thereof;   spreading the mixture tangentially along the tank sidewall;   passing the mixture axially through a perforated baffle plate in the tank;   separating gas with adherent oil droplets and oil from the mixture;   allowing the oil and the gas with adherent oil droplets to rise to an outlet at the top of the tank and discharge from the tank; and   conveying cleaned produced water to an outlet at the bottom of the tank.   
     
     
         11 . The method of  claim 10 , wherein feeding the mixture into a tank along an axis thereof comprises flowing the mixture through an inlet oriented along the axis. 
     
     
         12 . The method of  claim 11 , wherein spreading the mixture tangentially along the tank sidewall comprises flowing the mixture through a nozzle extending from the inlet toward the sidewall. 
     
     
         13 . The method of  claim 12 , wherein the perforated baffle plate is mounted below the nozzle within the tank. 
     
     
         14 . The method of  claim 13 , wherein the perforated baffle plate has openings, and wherein a total area of the openings is at least 15% of the area of the perforated baffle plate. 
     
     
         15 . The method of  claim 14 , wherein spreading the mixture tangentially along the tank sidewall comprises flowing the mixture on a guide vane extending radially inward from the sidewall and between the sidewall and a shroud disposed radially inward from the sidewall. 
     
     
         16 . The method of  claim 15 , further comprising spreading the mixture tangentially along the tank sidewall a second time. 
     
     
         17 . The method of  claim 16 , wherein spreading the mixture tangentially along the tank sidewall a second time comprises flowing the mixture through an annulus chamber. 
     
     
         18 . A method, comprising:
 adding gas to an oil-containing produced water to form a mixture;   feeding the mixture into a tank through an inlet oriented along an axis of the tank;   spreading the mixture radially outward through a plurality of nozzles extending from the inlet toward the tank sidewall and ending tangentially along the tank sidewall;   passing the mixture axially through a perforated baffle plate in the tank below the plurality of nozzles;   separating gas with adherent oil droplets and oil from the mixture;   allowing the oil and the gas with adherent oil droplets to rise to an outlet at the top of the tank and discharge from the tank; and   conveying cleaned produced water to an outlet at the bottom of the tank.   
     
     
         19 . The method of  claim 18 , wherein spreading the mixture radially outward comprises flowing the mixture on a guide vane extending radially inward from the sidewall and between the sidewall and a shroud disposed radially inward from the sidewall. 
     
     
         20 . The method of  claim 19 , further comprising flowing the mixture through an annulus chamber and spreading the mixture radially outward through a second plurality of nozzles extending from the annulus chamber toward the tank sidewall and ending tangentially along the tank sidewall.