Gas oil separation plant systems and methods for rag layer treatment

Patent metadata

Field	Value
Publication number	US-10513663-B2
Application number	US-201815866100-A
Country	US
Kind code	B2
Filing date	Jan 9, 2018
Priority date	Jan 9, 2018
Publication date	Dec 24, 2019
Grant date	Dec 24, 2019

Abstract

Systems and methods for treating a rag layer in a gas oil separation plant. The method includes withdrawing the rag layer from a vessel proximate an oil water interface; conveying the rag layer to a separation device, the separation device operable to effect electrostatic coalescence on the rag layer to separate oil and water; and recycling separated oil from the separation device back to the gas oil separation plant process.

First claim

What is claimed is:

1. A system for treating a rag layer in a gas oil separation plant process, the system comprising:
an outlet stream to withdraw the rag layer from a first vessel proximate an oil water interface;
a separation device, the separation device in fluid communication with the outlet stream and operable to effect electrostatic coalescence on the rag layer to separate oil and water; and
a recycle line to recycle separated oil from the separation device back to a second vessel of the gas oil separation plant process,
where the system is operable to open a water level control valve on the outlet stream in response to a deactivation signal from the separation device to reduce a water level in the first vessel to below an oily water interface skimmer such that the oil water interface is proximate the oily water interface skimmer, and
where the system is operable to withdraw the rag layer in part based on a pressure differential between a pressure in the first vessel and a pressure in the second vessel, the pressure in the first vessel being greater than the pressure in the second vessel.

2. The system according to claim 1 , where the first vessel is selected from the group consisting of: a dehydrator and a desalter.

3. The system according to claim 2 , wherein the second vessel comprises a low pressure production trap; and further comprises a third vessel selected from the group consisting of a dehydrator and a desalter and is different from the first vessel; and where a hydrocarbon inlet stream to the low pressure production trap and a hydrocarbon inlet stream to the dehydrator are heated by heat exchangers to increase efficiency of water/oil separation in the system.

4. The system according to claim 1 , where the separation device is selected from the group consisting of: a three-phase separation device equipped with fully insulated electrostatic electrodes and a spool of pipe equipped with fully insulated electrostatic electrodes.

5. The system according to claim 1 , further comprising a level indicator and controller in communication with the vessel and in communication with a control valve, the control valve in fluid communication with the vessel via the outlet stream.

6. The system according to claim 1 , the system operable to automatically discontinue conveying the rag layer to the separation device when the separation device detects 100% water being withdrawn from the vessel.

7. The system according to claim 1 , further comprising a device to increase the pressure of the rag layer.

8. The system according to claim 7 , where the device to increase the pressure of the rag layer is selected from the group consisting of: a turbocharger; a pump; and combinations of the same.

Assignees

• Saudi Arabian Oil Co

Inventors

• Soliman Mohamed
• Alanazi Khalid F
• Salu Samusideen Adewale
• Zahrani Talal A

Classifications

• C10G32/02

  by electric or magnetic means · CPC title

• C02F1/463

  by electrocoagulation · CPC title

• C02F1/40

  Devices for separating or removing fatty or oily substances or similar floating material (cleaning or keeping clear the surface of open water from oil or like materials E02B15/04; devices in sewers for separating liquid or solid substances from sewage E03F5/14, e.g. for use in drains leading to the sewer E03F5/16) · CPC title

• B03C11/00

  Separation by high-voltage electrical fields, not provided for in other groups of this subclass · CPC title

• B03C2201/02

  Electrostatic separation of liquids from liquids · CPC title