# US 11,905,804 B2 · Stimulating hydrocarbon reservoirs > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,905,804 B2 - Document ID: US11905804B2 - Status: Granted - Kind: B2 - Application number: 17/829,972 - Filed: 2022-06-01 - Published: 2023-12-07 - Granted: 2024-02-20 - Earliest claimed: 2022-06-01 - Assignees: Saudi Arabian Oil Company - Applicants: Saudi Arabian Oil Company - Inventors: Katherine Leigh Hull; Amy J. Cairns; Rajesh Kumar Saini - Web page: https://patentgrep.com/patent/US11905804B2 ## CPC - E21B 43/164: {Injecting CO2 or carbonated water (in combination with organic material C09K8/594)} - E21B 43/27: by use of eroding chemicals, e.g. acids - C09K 8/594: Compositions used in combination with injected gas {, e.g. CO2 orcarbonated gas}(C09K8/592 takes precedence) - C09K 8/74: combined with additives added for specific purposes - E21B 43/25: Methods for stimulating production {(by vibrating earth formations E21B43/003)} - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE ## Abstract Techniques for treating a hydrocarbon reservoir include delivering a composition to the hydrocarbon reservoir. The composition includes at least one acid, and liquid or supercritical carbon dioxide (CO2). The method further includes exposing the delivered composition to water to activate the composition; and treating a rock formation of the hydrocarbon reservoir with the activated composition. ## Claims ### Claim 1 A method for treating a hydrocarbon reservoir, comprising: delivering a composition to the hydrocarbon reservoir, the composition comprising: at least one acid, and liquid or supercritical carbon dioxide (CO2); exposing the delivered composition to water to activate the composition; and treating a rock formation of the hydrocarbon reservoir with the activated composition, wherein the at least one acid is dissolved in the liquid or supercritical CO2 with a cosolvent or surfactant, and the at least one acid is stearic acid, and the cosolvent or surfactant is selected from the group consisting of acetic acid, acetic acid and acetonitrile, ethanol, ethanol and acetonitrile, and methyl acetate. ### Claim 2 (depends on 1) The method of claim 1, wherein exposing the delivered composition to water comprises at least one of: exposing the delivered composition to subterranean water in the hydrocarbon reservoir; or delivering the water to the hydrocarbon reservoir separately from the delivered composition to expose the delivered composition to the water. ### Claim 3 (depends on 2) The method of claim 2, wherein delivering the composition comprises delivering the composition in a first fluid slug, the method further comprising delivering, in a second fluid slug subsequent to the first fluid slug, another acid to the hydrocarbon reservoir that is independent of the liquid or supercritical CO2. ### Claim 4 (depends on 3) The method of claim 3, further comprising delivering a spacer to the hydrocarbon reservoir between the first and second fluid slugs. ### Claim 5 (depends on 2) The method of claim 2, further comprising: delivering a pre-flush to the hydrocarbon reservoir prior to delivering the composition to the hydrocarbon reservoir; and delivering a post-flush to the hydrocarbon reservoir subsequent to delivering the composition to the hydrocarbon reservoir. ### Claim 6 (depends on 5) The method of claim 5, further comprising diverting the delivered composition to a particular location in the hydrocarbon reservoir. ### Claim 7 (depends on 2) The method of claim 2, further comprising diverting the delivered composition to a particular location in the hydrocarbon reservoir. ### Claim 8 (depends on 1) The method of claim 1, wherein delivering the composition comprises delivering the composition in a first fluid slug, the method further comprising delivering, in a second fluid slug subsequent to the first fluid slug, another acid to the hydrocarbon reservoir that is independent of the liquid or supercritical CO2. ### Claim 9 (depends on 8) The method of claim 8, further comprising delivering a spacer to the hydrocarbon reservoir between the first and second fluid slugs. ### Claim 10 (depends on 1) The method of claim 1, further comprising: delivering a pre-flush to the hydrocarbon reservoir prior to delivering the composition to the hydrocarbon reservoir; and delivering a post-flush to the hydrocarbon reservoir subsequent to delivering the composition to the hydrocarbon reservoir. ### Claim 11 (depends on 1) The method of claim 1, further comprising diverting the delivered composition to a particular location in the hydrocarbon reservoir. ### Claim 12 A method for treating a hydrocarbon reservoir, comprising: delivering a composition to the hydrocarbon reservoir, the composition comprising: at least one acid, and liquid or supercritical carbon dioxide (CO2); delivering water to the hydrocarbon reservoir separately from the composition to activate the composition; and treating a rock formation of the hydrocarbon reservoir with the activated composition, wherein the at least one acid is dissolved in the liquid or supercritical CO2 with a cosolvent or surfactant, and the at least one acid is stearic acid, and the cosolvent or surfactant is selected from the group consisting of acetic acid, acetic acid and acetonitrile, ethanol, ethanol and acetonitrile, and methyl acetate. ### Claim 13 (depends on 12) The method of claim 12, wherein delivering the composition comprises delivering the composition in a first fluid slug, the method further comprising delivering, in a second fluid slug subsequent to the first fluid slug, another acid to the hydrocarbon reservoir that is independent of the liquid or supercritical CO2. ### Claim 14 (depends on 13) The method of claim 13, further comprising delivering a spacer to the hydrocarbon reservoir between the first and second fluid slugs. ### Claim 15 (depends on 12) The method of claim 12, further comprising: delivering a pre-flush to the hydrocarbon reservoir prior to delivering the composition to the hydrocarbon reservoir; and delivering a post-flush to the hydrocarbon reservoir subsequent to delivering the composition to the hydrocarbon reservoir. ### Claim 16 (depends on 12) The method of claim 12, further comprising diverting the delivered composition to a particular location in the hydrocarbon reservoir. ### Claim 17 A method for treating a hydrocarbon reservoir, comprising: delivering a composition to the hydrocarbon reservoir, the composition comprising: at least one acid, and liquid or supercritical carbon dioxide (CO2); exposing the delivered composition to subterranean water in the hydrocarbon reservoir to activate the composition; and treating a rock formation of the hydrocarbon reservoir with the activated composition, wherein the at least one acid is dissolved in the liquid or supercritical CO2 with a cosolvent or surfactant, and the at least one acid is stearic acid, and the cosolvent or surfactant is selected from the group consisting of acetic acid, acetic acid and acetonitrile, ethanol, ethanol and acetonitrile, and methyl acetate. ### Claim 18 (depends on 17) The method of claim 17, wherein delivering the composition comprises delivering the composition in a first fluid slug, the method further comprising delivering, in a second fluid slug subsequent to the first fluid slug, another acid to the hydrocarbon reservoir that is independent of the liquid or supercritical CO2. ### Claim 19 (depends on 18) The method of claim 18, further comprising delivering a spacer to the hydrocarbon reservoir between the first and second fluid slugs. ### Claim 20 (depends on 17) The method of claim 17, further comprising: delivering a pre-flush to the hydrocarbon reservoir prior to delivering the composition to the hydrocarbon reservoir; and delivering a post-flush to the hydrocarbon reservoir subsequent to delivering the composition to the hydrocarbon reservoir. ### Claim 21 (depends on 17) The method of claim 17, further comprising diverting the delivered composition to a particular location in the hydrocarbon reservoir.