Acidic aqueous solution containing a chelating agent and the use thereof

Patent metadata

Field	Value
Publication number	US-9803134-B2
Application number	US-81235808-A
Country	US
Kind code	B2
Filing date	Oct 10, 2008
Priority date	Jan 9, 2008
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

An acidic aqueous solution containing a chelating agent and an acid, wherein the chelating agent is glutamic acid N,N-diacetic acid (GLDA) or a salt thereof, and wherein the amount of GLDA or the salt thereof is at least 10 wt %, based on the weight of the aqueous solution, and to the use thereof as an oilfield chemical, in descaling processes, or in processes in which highly concentrated aqueous acids are used, such as cleaning processes or plating processes.

First claim

The invention claimed is:

1. A process of using an acidic aqueous solution in an oil field in completion or stimulation, the process comprising at least one of acidizing, fracturing or descaling with the acidic aqueous solution,
wherein the acidic aqueous solution contains a chelating agent and an acid,
wherein the chelating agent is glutamic acid N,N-diacetic acid (GLDA) or a salt thereof and is dissolved in the acidic aqueous solution,
wherein the amount of GLDA or the salt thereof is at least 10 and up to 60 wt %, based on the weight of the aqueous solution, and
wherein the acid is selected from the group consisting of hydrochloric acid, hydrobromic acid, hydrofluoric acid, hydroiodic acid, sulfuric acid, nitric acid, phosphoric acid, formic acid, acetic acid, citric acid, lactic acid, malic acid, tartaric acid, maleic acid, boric acid, hydrogen sulfide, and a mixture of two or more of these acids.

2. The process of claim 1 , wherein the acidic aqueous solution has a pH of below 3.

3. The process of claim 1 , wherein the process comprises acidizing with the acidic aqueous solution.

4. The process of claim 3 , wherein the acidic aqueous solution has a pH of below 3.

5. The process of claim 1 , wherein the process comprises fracturing with the acidic aqueous solution.

6. The process of claim 5 , wherein the acidic aqueous solution has a pH of below 3.

7. The process of claim 1 , wherein the process comprises descaling with the acidic aqueous solution.

8. The process of claim 7 , wherein the acidic aqueous solution has a pH of below 3.

9. The process of claim 1 , wherein the amount of the acid is at least 5 wt %.

10. The process of claim 1 , wherein the acidic aqueous solution has a pH of below 1.

11. A process comprising cleaning, plating or descaling with an acidic aqueous solution containing a chelating agent and an acid,
wherein the chelating agent is glutamic acid N,N-diacetic acid (GLDA) or a salt thereof and is dissolved in the acidic aqueous solution,
wherein the amount of GLDA or the salt thereof is at least 10 and up to 60 wt %, based on the weight of the aqueous solution, and
wherein the acid is selected from the group consisting of hydrochloric acid, hydrobromic acid, hydrofluoric acid, hydroiodic acid, sulfuric acid, nitric acid, phosphoric acid, formic acid, acetic acid, citric acid, lactic acid, malic acid, tartaric acid, maleic acid, boric acid, hydrogen sulfide, and a mixture of two or more of these acids.

12. The process of claim 11 , wherein the process comprises cleaning with the acidic aqueous solution.

13. The process of claim 12 , wherein the acidic aqueous solution has a pH of below 3.

14. The process of claim 11 , wherein the process comprises plating with the acidic aqueous solution.

15. The process of claim 14 , wherein the acidic aqueous solution has a pH of below 3.

16. The process of claim 11 , wherein the process comprises descaling with the acidic aqueous solution.

17. The process of claim 16 , wherein the acidic aqueous solution has a pH of below 3.

18. The process of claim 11 , wherein the acidic aqueous solution has a pH of below 3.

19. The process of claim 11 , wherein the acidic aqueous solution is substantially free of bismuth.

20. The process of claim 11 , wherein the acidic aqueous solution is substantially free of hydrogen peroxide.

21. The process of claim 11 , wherein the amount of the acid is at least 5 wt %.

22. An acidic aqueous solution containing a chelating agent, an acid, and an additive,
wherein the chelating agent is glutamic acid N,N-diacetic acid (GLDA) or a salt thereof and is dissolved in the acidic aqueous solution,
wherein the amount of GLDA or the salt thereof is at least 10 and up to 60 wt %, based on the weight of the aqueous solution, and
wherein the acid is selected from the group consisting of hydrochloric acid, hydrobromic acid, hydrofluoric acid, hydroiodic acid, sulfuric acid, nitric acid, phosphoric acid, formic acid, acetic acid, citric acid, lactic acid, malic acid, tartaric acid, maleic acid, boric acid, hydrogen sulfide, and a mixture of two or more of these acids and wherein the additive is selected from the group consisting of surfactants, builders, wetting agents, emulsifiers, and bleaching agents.

23. The acidic aqueous solution of claim 22 having a pH of below 3.

24. The acidic aqueous solution of claim 22 , wherein the acidic aqueous solution is substantially free of bismuth.

25. The acidic aqueous solution of claim 22 , wherein the acidic aqueous solution is substantially free of hydrogen peroxide.

26. The process of claim 22 , wherein the amount of the acid is at least 5 wt %.

Assignees

• De Wolf Cornelia Adriana
• Lepage James N
• Bemelaar Johanna Hendrika
• Akzo Nobel Chemicals Int Bv

Inventors

• De Wolf Cornelia Adriana
• Lepage James N
• Bemelaar Johanna Hendrika

Classifications

• C11D3/30

  Amines; Substituted amines {; Quaternized amines} · CPC title

• C25D3/02

  from solutions (C25D5/34 - C25D5/46 take precedence) · CPC title

• C11D3/2075

  Carboxylic acids-salts thereof · CPC title

• C11D3/042

  Acids · CPC title

• C11D7/08

  Acids · CPC title