Configurations and methods of dewatering crude oil
A process for dewatering crude oil is described. The process includes feeding crude oil onto a separation of a cyclone separator that is at least partially disposed in a flash vessel. The temperature are pressure in the flash vessel are selected such that at least 20% of the water contained in the crude oil is flashed from the crude oil as it moves on the separation surface of the cyclone separator. The flow rate and angle of the crude oil inlet is selected such that the crude oil moves across the separation surface as a film in a helical pattern, providing a substantial foaming-free manner. The vapor that is flashed from the crude oil exits the flash vessel at a top outlet and the liquid crude oil exits the flash vessel at a bottom outlet.
1. A method of water removal from crude oil and water mixture, comprising:
feeding the crude oil and water mixture at a flow rate and a temperature onto an interior separation surface of a cyclone separator as a thin film, wherein the crude oil and water mixture are fed to an inlet at a top of the cyclone separator, wherein the cyclone separator is at least partially disposed within a flash vessel;
flashing at least 20% of the water contained in the crude oil as steam from the crude oil while the crude oil and water mixture is moving on the separation surface in a helical pattern as a thin film;
collapsing foam bubbles on the separation surface of the cyclone separator; and
wherein the separation surface, a pressure in the flash vessel, the temperature of the crude oil in the cyclone separator, and the flow rate are selected such as to allow flashing of the water as steam from the crude oil without foam carry-over into a vapor phase leaving the flash vessel.
2. The method of claim 1 , wherein the flash vessel has a crude oil inlet for feeding the crude oil onto the separation surface; wherein the separation surface of the cyclone separator is not rotatable; wherein a flow of the crude oil and water mixture is downward; and wherein an area of the separation surface of the cyclone separator and an angular velocity of the crude oil and water mixture are configured to allow for water removal and prevention of foam.
3. The method of claim 2 , wherein the flash vessel has a liquid outlet that is located below the crude oil inlet.
4. The method of claim 2 , wherein the flash vessel has a vapor outlet that is located above the crude oil inlet.
5. The method of claim 1 , wherein the cyclone separator is suspended within the flash vessel by the inlet.
6. The method of claim 5 , wherein the separation surface, the pressure in the flash vessel, the temperature of the crude oil in the cyclone separator, and the flow rate are selected such as to allow flashing of at least 70% of water as steam from the crude oil in the flash vessel.
7. The method of claim 1 wherein the separation surface, the pressure in the flash vessel, the temperature of the crude oil in the cyclone separator, and the flow rate are selected such as to allow flashing of at least 90% of water as steam from the crude oil in the flash vessel.
8. The method of claim 1 , further comprising the steps of:
condensing the vapor phase leaving the flash vessel to form liquid water, some light hydrocarbon liquid, and a hydrocarbon vapor; and
separating the liquid water, the light hydrocarbon liquid, and the hydrocarbon vapor.
9. The method of claim 1 , further comprising:
operationally coupling a control unit to a flash vessel and programming the control unit to regulate at least one of a temperature of the crude oil in the flash vessel, a pressure in the flash vessel, and a flow rate of the crude oil such as to allow flashing of the crude oil in the flash vessel,
wherein feeding the crude oil at the flow rate and the temperature onto the separation surface of the cyclone separator comprises:
using the control unit to regulate the pressure in the flash vessel, the temperature of the crude oil in the flash vessel, and the flow rate to so enable flashing of at least 50% of water as steam from the crude oil in the flash vessel without foam carry-over into a vapor phase and a liquid phase leaving the flash vessel.
10. The method of claim 9 , wherein the flash vessel comprises a multi-cyclone separator at least partially disposed in a lumen of the flash vessel.
11. The method of claim 1 , wherein feeding the crude oil at the flow rate and the temperature onto the separation surface of the cyclone separator comprises:
moving the crude oil on the separation surface across a pressure gradient and at a velocity and angle that are sufficient to suppress foam formation; and
wherein the temperature of the crude oil is sufficient to allow flashing of the steam at the pressure gradient.
12. The method of claim 11 , wherein the pressure gradient is a pressure drop of at least 10 psig.
13. The method of claim 11 , further comprising the step of adjusting at least one of the temperature and the pressure gradient to allow flashing.
14. The method of claim 11 , wherein the angle is sufficient for cyclone separation.
15. The method of claim 11 , wherein the film has a thickness of between 1 mm and 20 mm.
16. The method of claim 11 , wherein the separation surface is part of a cyclone separator.
17. The method of claim 1 , wherein the crude oil and water mixture is free from diluents.