# US 5,341,878 A · Fatty acid salts as steam foaming agents > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,341,878 A - Document ID: US5341878A - Status: Granted - Kind: A - Application number: 07/996,741 - Filed: 1992-12-24 - Granted: 1994-08-30 - Earliest claimed: 1992-12-24 - Assignees: Texaco Inc. - Inventors: William T. Osterloh - Web page: https://patentgrep.com/patent/US5341878A ## CPC - C09K 8/594: Compositions used in combination with injected gas {, e.g. CO2 orcarbonated gas}(C09K8/592 takes precedence) - C09K 8/58: Compositions for enhanced recovery methods for obtaining hydrocarbons, i.e. for improving the mobility of the oil, e.g. displacing fluids - E21B 43/24: using heat, e.g. steam injection - Y10S 507/936: Flooding the formation - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract A steam foam method of recovering hydrocarbons from an underground hydrocarbon formation, which comprises injecting steam through an injection well into the formation, injecting an aqueous solution having a salinity greater than about 1% by weight and a pH of about 8 to about 12, comprising about 0.1% to about 5% by weight of a fatty acid salt having about 10 to about 24 carbon atoms, and injecting steam into the formation to sweep hydrocarbons towards the production well for recovery. ## Claims ### Claim 1 A method of recovering hydrocarbons from an underground hydrocarbon formation penetrated by at least one injection well and at least one production well, which comprises: injecting steam through an injection well into the formation; injecting through the injection well into the formation an aqueous solution having a salinity greater than about 1% and a pH of about 8 to about 12 comprising about 0.1% to about 5% by weight of a fatty acid salt having about 10 to about 24 carbon atoms; and injecting steam through the injection well into the formation to sweep hydrocarbons towards a production well for recovery. ### Claim 2 (depends on 1) The method of claim 1, wherein the fatty acid salt of said aqueous solution is solvated in the aqueous phase of injected steam. ### Claim 3 (depends on 1) The method of claim 1, wherein the fatty acid salt is an unsaturated fatty acid salt. ### Claim 4 (depends on 1) The method of claim 1, wherein the fatty acid salt is a saturated fatty acid salt. ### Claim 5 (depends on 1) The method of claim 1, wherein the fatty acid salt is a mixture of saturated and unsaturated fatty acid salts. ### Claim 6 (depends on 1) The method of claim 1, wherein the fatty acid salt is a tall oil acid salt. ### Claim 7 (depends on 6) The method of claim 6, wherein the fatty acid salt is an oleic acid salt. ### Claim 8 (depends on 6) The method of claim 6, wherein the fatty acid salt is a linoleic acid salt. ### Claim 9 (depends on 1) The method of claim 1, wherein the aqueous solution further comprises a basic buffer to help maintain the pH of the solution between about 8 and about 12. ### Claim 10 (depends on 9) The method of claim 9, wherein the basic buffer is sodium sesquicarbonate, sodium carbonate, or sodium bicarbonate/sodium hydroxide, or disodium hydrogen phosphate/sodium hydroxide. ### Claim 11 (depends on 1) The method of claim 1, wherein the aqueous solution comprises about 1% to about 3% of an inorganic salt. ### Claim 12 (depends on 11) The method of claim 11, wherein the inorganic salt is sodium chloride, potassium chloride, or lithium chloride. ### Claim 13 (depends on 1) The method of claim 1, wherein the fatty acid salt is injected into the formation with the initial injection of steam. ### Claim 14 (depends on 1) The method of claim 1, wherein the fatty acid salt is injected into the formation prior to steam breakthrough at a production well. ### Claim 15 (depends on 1) The method of claim 1, wherein the fatty acid salt is injected into the formation after steam breakthrough at a production well. ### Claim 16 (depends on 1) The method of claim 1, wherein the aqueous solution is injected into a steam override zone. ### Claim 17 (depends on 1) The method of claim 1, wherein the aqueous solution comprises about 0.3% to about 1% of the fatty acid salt. ### Claim 18 A method of recovering hydrocarbons from an underground hydrocarbon formation penetrated by at least one injection well and at least one production well, which comprises: injecting steam through an injection well into the formation; injecting an aqueous solution having a pH of about 8 to about 12 through the injection well into the formation, said aqueous solution comprising about 0.3% to about 1% by weight of a tall oil acid salt, sodium sesquicarbonate as a basic buffer to maintain the pH between about 8 to about 12, and about 0.5% to about 2.5% by weight of inorganic salt; and injecting steam through the injection well into the formation to sweep hydrocarbons towards a production well for recovery. ### Claim 19 A method of recovering hydrocarbons from an underground hydrocarbon formation penetrated by at least one well which comprises: injecting steam through an injection/production well into the formation: injecting through the injection/production well into the formation an aqueous solution having a salinity greater than about 1% and a pH of about 8 to about 12 comprising about 0.1% to about 5% by weight of a fatty acid salt having about 10 to about 24 carbon atoms; injecting steam through the injection/production well into the formation; producing hydrocarbons and other fluids through the injection/production well. ### Claim 20 (depends on 19) The method of claim 19, wherein the injected steam is allowed to soak in the formation for about one to about fourteen days prior to producing hydrocarbons and other fluids. ### Claim 21 (depends on 19) The method of claim 19, wherein the fatty acid salt is a tall oil acid salt. ### Claim 22 (depends on 19) The method of claim 19, wherein the aqueous solution further comprises a basic buffer to help maintain the pH of the solution between about 8 and about 12. ### Claim 23 (depends on 19) The method of claim 19, wherein the aqueous solution comprises about 1% to about 3% of an inorganic salt. ### Claim 24 (depends on 19) The method of claim 19, wherein the aqueous solution comprises about 0.3% to about 1% of the fatty acid salt. ### Claim 25 A method of recovering hydrocarbons from an underground hydrocarbon formation penetrated by at least one well, which comprises: injecting steam through an injection/production well into the formation; injecting an aqueous solution having a pH of about 8 to about 12 through the injection/production well into the formation, said aqueous solution comprising about 0.3% to about 1% by weight of a tall oil acid salt, sodium sesquicarbonate as a basic buffer to maintain the pH between about 8 and about 12, and about 0.5% to about 2.5% by weight of inorganic salt; injecting steam through the injection/production well into the formation; allowing the injected steam to soak in the formation for about one to about fourteen days; and producing hydrocarbons and other fluids through the injection/production well.