Apparatus and method for separation of hydrocarbons from hydrocarbon-containing produced water

1. An apparatus for separation of hydrocarbons from hydrocarbon-containing produced water, comprising;

a separator tank;

an inlet tube;

a branch means for distribution of the produced water

a distribution tube extending from the branch means and ending in a first outlet nozzle;

a guide vane mounted under the outlet nozzle to lead water over to a next outlet nozzle;

an outlet in the bottom of the tank for cleaned water;

an outlet for removal of rising gas with adherent oil droplets; and

a shroud fixed entirely or partly along the inside of the guide vane in an angle of 30° to 150° related to the guide vane.

2. The apparatus of claim 1 , wherein the shroud extends upwards from the guide vane in a distance corresponding to the width of the vane.

3. The apparatus of claim 1 , wherein the shroud is arranged on the inside of the guide vane in an angle of 50° to 120°.

4. The apparatus of claim 1 , wherein the shroud comprises an annular wall fixed to the guide vane.

5. The apparatus of claim 1 , wherein a plate separates the separator tank into two chambers.

6. The apparatus of claim 5 , wherein the apparatus further comprises a vortex breaker, and wherein a chamber encircles the inlet tube and comprises a branch means.

7. A method for separation of hydrocarbons from hydrocarbon-containing produced water in a pressure tank, comprising:

supplying the hydrocarbon-containing produced water and mixing the hydrocarbon-containing produced water with a gas-containing component;

feeding the gas-and-hydrocarbon-containing produced water mixture to an inlet tube in the centre of a tank;

distributing said mixture via a branch means tangentially along the tank wall via distribution tubes, each with a first outlet nozzle;

leading said mixture over to a next outlet nozzle by a guide vane mounted under each outlet nozzle and a shroud fixed to the guide vane in an angle of 30° to 150°;

allowing hydrocarbons and gas with adherent oil droplets to rise to an outlet from the tank;

discharging the hydrocarbons and gas with adherent oil droplets from said tank through the outlet; and

conveying cleaned water to an outlet in the bottom of the tank.

8. The method of claim 7 , further comprising:

recirculating at least a portion of the cleaned water into the tank.

9. The method of claim 8 , wherein the recirculating comprises:

mixing the at least a portion of cleaned water with another gas-containing component;

feeding the gas-and-at least a portion of clean water mixture to an annulus chamber that encircles the inlet tube; and

distributing the gas-and-at least portion of clean water mixture via a second branch means tangentially along the tank wall.

10. The method of claim 7 , further comprising:

adjusting a ratio within the gas-and-hydrocarbon-containing produced water mixture feed to the inlet tube.

11. The method of claim 7 , further comprising:

allowing the cleaned water to pass through packing materials within the tank;

discharging the cleaned water from the bottom of the tank.

12. An apparatus for separation of hydrocarbons from a hydrocarbon-containing produced water stream mixed with a gas-containing component, comprising;

a separator tank;

an inlet tube to receive the produced water stream in the tank;

a distribution tube with an outlet nozzle to distribute the produced water stream from the inlet tube;

a guide vane mounted under the outlet nozzle to receive and lead the produced water stream over to a next outlet nozzle;

a shroud positioned on an interior surface of the guide vane;

an outlet at the bottom of the tank to convey cleaned water out of the tank; and

an outlet at the top of the tank to convey rising gas with adherent oil droplets from the tank.

13. The apparatus of claim 12 , wherein the shroud is angled between about 30° to 150° with respect to an axis of the tank.

14. The apparatus of claim 12 , further comprising:

an annulus chamber formed about the inlet tube to receive a gas-and-clean water mixture in the tank; and

a second distribution tube to distribute the gas-and-clean water mixture from the annulus chamber.

15. The apparatus of claim 12 , wherein the outlet nozzle is positioned tangentially along a tank wall.

16. The apparatus of claim 12 , further comprising an adjustable nozzle means connected to the inlet tube.

17. The apparatus of claim 12 , further comprising packing materials positioned within the tank to filter cleaned water at the bottom of the tank.