Iron sulfide dissolver

Patent metadata

Field	Value
Publication number	US-10501679-B2
Application number	US-201815885207-A
Country	US
Kind code	B2
Filing date	Jan 31, 2018
Priority date	Jan 31, 2018
Publication date	Dec 10, 2019
Grant date	Dec 10, 2019

Abstract

An aqueous iron sulfide dissolver including zinc, chromium, a methoxybenzoic acid, formic acid, acetic acid, and hydrochloric acid. The iron sulfide dissolver is made by combining these components, and dissolves compounds including iron sulfide upon contact. Evolved hydrogen sulfide reacts with the methoxybenzoic acid to yield solubilized methanethiol as an intermediate product, which is further oxidized to yield dissolved dimethyl disulfide.

First claim

What is claimed is:

1. An aqueous iron sulfide dissolver comprising:
zinc;
chromium;
a methoxybenzoic acid, wherein “methoxybenzoic acid” refers to the methoxybenzoic acid and its conjugate base;
formic acid, wherein “formic acid” refers to formic acid and its conjugate base;
acetic acid, wherein “acetic acid” refers to acetic acid and its conjugate base; and
hydrochloric acid, wherein “hydrochloric acid” refers to hydrochloric acid and its conjugate base.

2. The aqueous iron sulfide dissolver of claim 1 , wherein the methoxybenzoic acid comprises a trimethoxybenzoic acid.

3. The aqueous iron sulfide dissolver of claim 2 , wherein the trimethoxybenzoic acid comprises 3,4,5-trimethoxybenzoic acid.

4. The aqueous iron sulfide dissolver of claim 1 , wherein the methoxybenzoic acid comprises a dimethoxybenzoic acid.

5. The aqueous iron sulfide dissolver of claim 4 , wherein the dimethoxybenzoic acid comprises syringic acid (3,5-dimethoxy-4-hydroxybenzoic acid).

6. The aqueous iron sulfide dissolver of claim 1 , wherein a molar ratio of the zinc to the chromium is in a range of 1 to 3.

7. The aqueous iron sulfide dissolver of claim 1 , wherein the molar ratio of the zinc to the chromium is in a range of 1.5 to 2.5.

8. The aqueous iron sulfide dissolver of claim 1 , wherein a molar ratio of the formic acid to the chromium is in a range of 3.5 to 5.5.

9. The aqueous iron sulfide dissolver of claim 1 , wherein a molar ratio of the acetic acid to the chromium is in a range of 2.5 to 4.5.

10. The aqueous iron sulfide dissolver of claim 1 , wherein a molar ratio of the hydrochloric acid to the chromium is in a range of 1 to 3.

11. The aqueous iron sulfide dissolver of claim 10 , wherein the molar ratio of the hydrochloric acid to the chromium is in a range of 1.5 to 2.5.

12. The aqueous iron sulfide dissolver of claim 11 , wherein the molar ratio of the hydrochloric acid to the chromium is in a range of 2 to 2.5.

13. The aqueous iron sulfide dissolver of claim 1 , wherein a molar ratio of the methoxybenzoic acid to the chromium is in a range of 1.1 to 2.5.

14. The aqueous iron sulfide dissolver of claim 13 , wherein the molar ratio of the methoxybenzoic acid to the chromium is in a range of 1.5 to 2.

15. A method of making an aqueous iron sulfide dissolver for dissolving iron sulfides, the method comprising:
combining zinc, chromium, a methoxybenzoic acid, formic acid, acetic acid, and hydrochloric acid to yield the aqueous iron sulfide dissolver.

16. The method of claim 15 , wherein the zinc is in the form of zinc metal.

17. The method of claim 15 , wherein the chromium is in the form of a chromium salt.

18. A method of dissolving an iron sulfide, the method comprising:
contacting an iron sulfide with an aqueous iron sulfide dissolver comprising zinc, chromium, a methoxybenzoic acid, formic acid, acetic acid, and hydrochloric acid to dissolve the iron sulfide;
reacting evolved hydrogen sulfide with the methoxybenzoic acid to yield methanethiol; and
dimerizing the methanethiol to yield dimethyl disulfide in solution.

19. The method of claim 18 , further comprising introducing the aqueous iron sulfide dissolver into a wellbore, wherein contacting the iron sulfide with the aqueous iron sulfide dissolver occurs downhole.

20. The method of claim 18 , further comprising removing the dimethyl disulfide from the solution.

Assignees

• Saudi Arabian Oil Co

Inventors

• Oduro Harry Daniel
• Khaldi Mohammed

Classifications

• C09K2208/20

  Hydrogen sulfide elimination · CPC title

• C07C321/14

  of an acyclic saturated carbon skeleton · CPC title

• C01G49/12

  Sulfides {(C01G49/0018 takes precedence)} · CPC title

• C01G9/00

  Compounds of zinc · CPC title

• C07C53/08

  Acetic acid (pyroligneous acid C10C; preparation of vinegar C12J) · CPC title