Low salinity water production in crude oil processing

Patent metadata

Field	Value
Publication number	US-12448575-B2
Application number	US-202318355921-A
Country	US
Kind code	B2
Filing date	Jul 20, 2023
Priority date	Jul 20, 2023
Publication date	Oct 21, 2025
Grant date	Oct 21, 2025

Abstract

A side-stream is separated from an oil phase stream that is discharged from a crude oil separator in a gas-oil separation plant. The side-stream contains water and oil. At least a portion of the oil phase stream that is discharged from the crude oil separator in the gas-oil separation plant is flowed to a desalter in the gas-oil separation plant. An electric field is applied across the side-stream to coalesce aqueous droplets present in the side-stream to form an aqueous phase. The aqueous phase is separated from the oil of the side-stream. At least a portion of the aqueous phase is evaporated to form a wastewater phase and a vapor phase. At least a portion of the vapor phase is condensed to produce a wash water. The wash water is flowed to the desalter. The wash water can be referred to washing water or dilution water.

First claim

What is claimed is:

1. A method comprising:
separating a side-stream from an oil phase stream discharged from a crude oil separator in a gas-oil separation plant, wherein the side-stream contains water and oil;
flowing at least a portion of the oil phase stream discharged from the crude oil separator in the gas-oil separation plant to a desalter in the gas-oil separation plant;
applying an electric field across the side-stream to coalesce aqueous droplets present in the side-stream to form an aqueous phase;
separating the aqueous phase from the oil of the side-stream;
evaporating at least a portion of the aqueous phase to form a wastewater phase and a vapor phase;
condensing at least a portion of the vapor phase to produce a wash water; and
flowing the wash water to the desalter.

2. The method of claim 1 , further comprising rejoining the oil from the side-stream with a remainder of the oil phase stream discharged from the crude oil separator to form a rejoined oil phase, and flowing the rejoined oil phase to a second crude oil separator in the gas-oil separation plant.

3. The method of claim 2 , further comprising separating, by the second crude oil separator, the rejoined oil phase into a gas phase, a second oil phase, and a second wastewater phase.

4. The method of claim 3 , wherein the portion of the oil phase stream discharged from the crude oil separator and flowed to the desalter comprises at least a portion of the second oil phase from the second crude oil separator.

5. The method of claim 4 , wherein at least the portion of the aqueous phase is evaporated via heat exchange with at least a portion of the gas phase from the second crude oil separator.

6. The method of claim 4 , further comprising heating the side-stream prior to coalescing the aqueous droplets.

7. The method of claim 6 , wherein the side-stream is heated via heat exchange with at least a portion of the aqueous phase.

8. The method of claim 7 , wherein the side-stream is additionally heated via heat exchange with at least a portion of the wastewater phase.

9. The method of claim 8 , wherein the wash water is produced independent of use of a membrane.

10. A system comprising:
a side-stream branching from an oil phase stream discharged from a crude oil separator in a gas-oil separation plant, wherein the side-stream contains water and oil;
a coalescer configured to receive the side-stream and apply an electric field across the side-stream to coalesce aqueous droplets present in the side-stream to form an aqueous phase separate from an oil phase;
a separator configured to receive the side-stream from the coalescer and separate the aqueous phase from the oil phase;
a heat exchanger configured to receive and evaporate at least a portion of the aqueous phase from the separator;
a knockout drum configured to receive the aqueous phase from the heat exchanger and separate the aqueous phase into a wastewater phase and a vapor phase;
a condenser configured to receive and cool the vapor phase to condense at least a portion of the vapor phase into a wash water; and
a desalter configured to receive and mix at least a portion of the oil phase stream discharged from the crude oil separator and the wash water.

11. The system of claim 10 , further comprising a second crude oil separator configured to receive a rejoined oil phase comprising the oil phase from the separator and a remainder of the oil phase stream discharged from the crude oil separator, wherein the second crude oil separator is configured to separate the rejoined oil phase into a gas phase, a second oil phase, and a second wastewater phase.

12. The system of claim 11 , wherein the portion of the oil phase stream discharged from the crude oil separator and received by the desalter comprises at least a portion of the second oil phase from the second crude oil separator.

13. The system of claim 12 , wherein the heat exchanger is configured to evaporate at least the portion of the aqueous phase via heat exchange with at least a portion of the gas phase from the second crude oil separator.

14. The system of claim 13 , further comprising a second heat exchanger upstream of the coalescer, wherein the second heat exchanger is configured to heat the side-stream prior to the coalescer receiving the side-stream.

15. The system of claim 14 , wherein the second heat exchanger is configured to heat the side-stream via heat exchange with at least a portion of the aqueous phase from the separator.

16. The system of claim 15 , further comprising a third heat exchanger upstream of the second heat exchanger, wherein the third heat exchanger is configured to further heat the side-stream prior to the coalescer receiving the side-stream.

17. The system of claim 16 , wherein the third heat exchanger is configured to further heat the side-stream via heat exchange with at least a portion of the wastewater phase from the knockout drum.

18. The system of claim 17 , wherein the system is configured to produce the wash water independent of use of a membrane.

19. A method comprising:
separating, in a first crude oil separator in a gas-oil separation plant, a crude oil stream into a first gas stream, a first oil stream, and a first aqueous stream, wherein the first oil stream contains water and oil;
splitting the first oil stream into a first portion and a second portion;
coalescing aqueous droplets present in the first portion to form an aqueous phase separate from an oil phase;
evaporating at least a portion of the aqueous phase to form a wastewater stream and a water vapor stream;
condensing the water vapor stream to produce a wash water stream;
mixing the oil phase with the second portion to form a rejoined oil phase;
separating, in a second crude oil separator in the gas-oil separation plant, the rejoined oil phase into a second gas stream, a second oil stream, and a second aqueous stream;
flowing at least a portion of the second oil stream to a desalter in the gas-oil separation plant; and
flowing the wash water stream to the desalter.

20. The method of claim 19 , further comprising, prior to coalescing the aqueous droplets, heating the first portion via heat exchange with at least a portion of the aqueous phase, at least a portion of the wastewater stream, or both.

Assignees

• Saudi Arabian Oil Co

Inventors

• Shariff Maher Maqbool
• Duval Sebastien A
• Less Simone
• Oshinowo Olanrewaju Malcolm

Classifications

• C10G2300/4081

  Recycling aspects · CPC title

• C10G2300/1033

  Oil well production fluids · CPC title

• C10G33/02

  with electrical or magnetic means · CPC title

• C10G53/06 Primary

  including only extraction steps, e.g. deasphalting by solvent treatment followed by extraction of aromatics · CPC title

• C10G31/08 Primary

  by treating with water · CPC title