# US 10,501,679 B2 · Iron sulfide dissolver > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,501,679 B2 - Document ID: US10501679B2 - Status: Granted - Kind: B2 - Application number: 15/885,207 - Filed: 2018-01-31 - Published: 2019-08-01 - Granted: 2019-12-10 - Earliest claimed: 2018-01-31 - Assignees: Saudi Arabian Oil Company - Applicants: Saudi Arabian Oil Company - Inventors: Harry Daniel Oduro; Mohammed Khaldi - Web page: https://patentgrep.com/patent/US10501679B2 ## CPC - C09K 8/532: Sulfur - C01G 9/00: Compounds of zinc - C01G 37/00: Compounds of chromium - C01G 49/12: Sulfides {(C01G49/0018 takes precedence)} - C07C 53/02: Formic acid - C07C 53/08: Acetic acid (pyroligneous acid C10C; preparation of vinegar C12J) - C07C 63/06: Benzoic acid - C07C 321/14: of an acyclic saturated carbon skeleton - C09K 8/528: inorganic depositions, e.g. sulfates or carbonates - C23G 1/088: {solutions containing organic acids} - C09K 2208/20: Hydrogen sulfide elimination - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - C01G: COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts or peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium, or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds containing nitrogen, other non-metals and metal C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanamide C01C3/16; thiocyanates C01C3/20) - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS - C23G: CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS ## 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. ## Claims ### Claim 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. ### Claim 2 (depends on 1) The aqueous iron sulfide dissolver of claim 1, wherein the methoxybenzoic acid comprises a trimethoxybenzoic acid. ### Claim 3 (depends on 2) The aqueous iron sulfide dissolver of claim 2, wherein the trimethoxybenzoic acid comprises 3,4,5-trimethoxybenzoic acid. ### Claim 4 (depends on 1) The aqueous iron sulfide dissolver of claim 1, wherein the methoxybenzoic acid comprises a dimethoxybenzoic acid. ### Claim 5 (depends on 4) The aqueous iron sulfide dissolver of claim 4, wherein the dimethoxybenzoic acid comprises syringic acid (3,5-dimethoxy-4-hydroxybenzoic acid). ### Claim 6 (depends on 1) 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. ### Claim 7 (depends on 1) 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. ### Claim 8 (depends on 1) 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. ### Claim 9 (depends on 1) 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. ### Claim 10 (depends on 1) 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. ### Claim 11 (depends on 10) 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. ### Claim 12 (depends on 11) 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. ### Claim 13 (depends on 1) 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. ### Claim 14 (depends on 13) 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. ### Claim 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. ### Claim 16 (depends on 15) The method of claim 15, wherein the zinc is in the form of zinc metal. ### Claim 17 (depends on 15) The method of claim 15, wherein the chromium is in the form of a chromium salt. ### Claim 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. ### Claim 19 (depends on 18) 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. ### Claim 20 (depends on 18) The method of claim 18, further comprising removing the dimethyl disulfide from the solution.