Methods of improving compatibility of oilfield produced water from different sources

Patent metadata

Field	Value
Publication number	US-11434151-B2
Application number	US-202016846734-A
Country	US
Kind code	B2
Filing date	Apr 13, 2020
Priority date	Apr 13, 2020
Publication date	Sep 6, 2022
Grant date	Sep 6, 2022

Abstract

a method of treating aqueous wellbore fluids, comprising (a) converting one or more multivalent cations in a multivalent cation-containing aqueous fluid to form a mixture comprising one or more insoluble compounds and a treated aqueous fluid, (b) separating the treated aqueous fluid from the one or more insoluble compounds, and (c) contacting the treated aqueous fluid with a sulfide-containing aqueous fluid to form a compatibilized aqueous fluid, wherein the multivalent cation-containing aqueous fluid, the sulfide-containing aqueous fluid, or both were recovered from wellbores prior to (c).

First claim

We claim:

1. A method of treating aqueous wellbore fluids, comprising:
(a) converting one or more multivalent cations in a multivalent cation-containing aqueous fluid to form a mixture comprising one or more insoluble compounds and a treated aqueous fluid;
(b) separating the treated aqueous fluid from the one or more insoluble compounds; and
(c) contacting the treated aqueous fluid with a sulfide-containing aqueous fluid to form a compatibilized aqueous fluid,
wherein the multivalent cation-containing aqueous fluid, the sulfide-containing aqueous fluid, or both were recovered from wellbores prior to (c).

2. The method of claim 1 , wherein the one or more multivalent cations comprise iron ion, iron (III) ion, magnesium (II) ion, calcium (II) ion, or any combination thereof.

3. The method of claim 1 , wherein the one or more multivalent cations are present in the multivalent cation-containing aqueous fluid in a total amount of from about 0.1 ppm to about 1,000 ppm.

4. The method of claim 1 , further comprising contacting the mixture with a flocculating agent prior to separating the one or more insoluble compounds from the treated aqueous fluid.

5. The method of claim 4 , wherein the flocculating agent comprises polyacrylamide, a polyacrylamide copolymer, acrylamide copolymer, aluminum hydroxide, aluminum salts, iron salts, calcium salts, silicates, polysaccharides, polyDADMAC, or any combination thereof.

6. The method of claim 4 , wherein a weight ratio of the flocculating agent to the one or more multivalent cations is in a range of from about 0.01:1 to about 100:1.

7. The method of claim 1 , wherein the converting comprises contacting the multivalent cation-containing aqueous fluid with a carbonate-containing compound.

8. The method of claim 7 , wherein the carbonate-containing compound comprises sodium carbonate, potassium carbonate, or any combination thereof.

9. The method of claim 7 , wherein a molar ratio of carbonate in the carbonate-containing compound to the one or more multivalent cations is in a range of from about 1:1 to about 2:1.

10. The method of claim 1 , wherein the one or more multivalent cations comprise iron (II).

11. The method of claim 10 , wherein the converting comprises contacting the iron (II) present in the multivalent cation-containing aqueous fluid with an oxidizing agent.

12. The method of claim 11 , wherein the oxidizing agent comprises air, oxygen, sodium hypochlorite, chlorine dioxide, persulfate, bromate, or any combination thereof.

13. The method of claim 11 , wherein a molar ratio of the oxidizing agent to the iron (II) is from about 1:6 to about 2:1.

14. A method of treating a wellbore fluid, comprising:
(a) recovering from a wellbore a wellbore fluid comprising one or more multivalent cations, hydrocarbons, and water;
(b) separating the hydrocarbons from the wellbore fluid to produce an oleaginous fluid and a produced water comprising the one or more multivalent cations;
(c) converting the one or more multivalent cations in the produced water to form a mixture comprising one or more insoluble compounds and a treated aqueous fluid;
(d) separating the treated aqueous fluid from the one or more insoluble compounds; and
(e) contacting the treated aqueous fluid with a sulfide-containing aqueous fluid.

15. The method of claim 14 , wherein separating the hydrocarbons from the wellbore fluid comprises contacting the wellbore fluid with a demulsifier.

16. The method of claim 14 further comprising prior to (e), recovering the sulfide-containing aqueous fluid from another wellbore.

17. The method of claim 14 , wherein the converting comprises: contacting the produced water with a carbonate-containing compound.

18. The method of claim 14 , wherein the one or more multivalent cations comprise iron (II), and wherein the converting comprises contacting the iron (II) in the produced water with an oxidizing agent.

19. The method of claim 14 , further comprising contacting the one or more insoluble compounds with a flocculating agent to form a sludge prior to separating the treated aqueous fluid from the one or more insoluble compounds contained in the sludge.

20. A method of treating an aqueous wellbore fluid containing iron (II) comprising:
contacting the aqueous wellbore fluid with sodium carbonate to form one or more insoluble compounds;
contacting the one or more insoluble compounds with a flocculating agent to form a mixture of a sludge and a treated aqueous fluid;
separating the treated aqueous fluid from the sludge; and
contacting the treated aqueous fluid with a sulfide-containing aqueous fluid.

Assignees

• Multi Chem Group Llc
• Halliburton Energy Services Inc

Inventors

• Li Chunli
• Li Leiming
• Hazlewood Johnathan Scott

Classifications

• C02F1/72

  by oxidation {(C02F1/4672 takes precedence)} · 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

• C02F1/56

  Macromolecular compounds · CPC title

• C02F5/08

  Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents · CPC title

• C02F2103/10

  from quarries or from mining activities · CPC title