# US 11,299,666 B2 · Surfactant composition for the reinjection of produced water > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,299,666 B2 - Document ID: US11299666B2 - Status: Granted - Kind: B2 - Application number: 16/763,530 - Filed: 2017-11-14 - Published: 2020-11-19 - Granted: 2022-04-12 - Earliest claimed: 2017-11-14 - Assignees: Total SA; Central National De La Recherche Scientifique - Applicants: Total SE; Centre National De La Recherche Scientifique; Sorbonne Universite; Ecole Superieure De Physique Et De Chimie Industrielles De La Ville De Paris - Inventors: Bertrand Levache; Aurélie Le Beulze; Nicolas Passade-Boupat - Web page: https://patentgrep.com/patent/US11299666B2 ## CPC - C09K 8/584: characterised by the use of specific surfactants - C09K 8/604: {Polymeric surfactants} - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE ## Abstract The invention relates to the use of a non-ionic surfactant and an anionic surfactant for enhancing the injectivity of an injection well, wherein the non-ionic surfactant and the anionic surfactant are added to produced water, to form a reinjection stream which is injected into a subterranean formation by the injection well. ## Claims ### Claim 1 A method for enhancing the injectivity of an injection well, comprising: adding a non-ionic surfactant and an anionic surfactant to water produced from the well, to form a reinjection stream; injecting the reinjection stream into a subterranean formation via the injection well such that the injectivity of the injection well is enhanced; wherein the anionic surfactant is of the formula R2—Y, wherein R2 is a saturated or unsaturated aliphatic or aromatic group having from 10 to 18 carbon atoms, a mean degree of unsaturation from 0 to 3, and a mean degree of branching of from 0 to 5; and wherein —Y is —O—(CH2CH(R3)O)m—(CH2CH2O)n—SO3−M+, wherein: R3 is an aliphatic or aromatic group having from 1 to 10 carbon atoms, m is from 1 to 20, n is from 0 to 5, and M+ is a monovalent cation. ### Claim 2 (depends on 1) The method of claim 1, wherein the injectivity of the injection well is increased by a factor of at least 1.5 relative to the injectivity of the injection well when the non-ionic surfactant and the anionic surfactant are not present in the reinjection stream containing produced water which is injected into the subterranean formation by the injection well. ### Claim 3 (depends on 1) The method of claim 1, wherein the injectivity of the injection well is maintained or restored at a level of at least 30%, relative to the maximal injectivity of the injection well. ### Claim 4 (depends on 1) The method of claim 1, wherein the total concentration of the non-ionic surfactant and anionic surfactant in the reinjection stream is less than 500 ppm by weight. ### Claim 5 (depends on 1) The method of claim 1, wherein the non-ionic surfactant is of formula R1—X, wherein R1 is a saturated or unsaturated aliphatic or aromatic group having from 10 to 18 carbon atoms, a mean degree of unsaturation from 0 to 3, and a mean degree of branching of from 0 to 5, and X is a hydrophilic group selected from the group consisting of polyoxyalkylene groups, sorbitan groups, polyethoxylated sorbitan groups, polyglyceryl groups and glycosidic groups. ### Claim 6 (depends on 5) The method of claim 5, wherein —X is —O—(CH2CH2O)p—H, and wherein p is from 1 to 20. ### Claim 7 (depends on 1) The method of claim 1, wherein the weight proportion of anionic surfactant relative to the total of the anionic surfactant and non-ionic surfactant in the reinjection stream is from 50 to 95%. ### Claim 8 (depends on 1) The method of claim 1, wherein the anionic surfactant and non-ionic surfactant are continuously added to the produced water for a period of time of at least 1 month. ### Claim 9 (depends on 1) The use of claim 1, wherein a nature and/or a proportion of the non-ionic surfactant and the anionic surfactant are selected by preparing a plurality of mixtures of non-ionic surfactant, anionic surfactant, produced water or simulated produced water, and oil, agitating the plurality of mixtures and identifying a mixture which provides a water/oil micro-emulsion. ### Claim 10 A method of extracting hydrocarbons from a subterranean formation, comprising: collecting a production stream comprising hydrocarbons and produced water from at least one hydrocarbon production well; separating the production stream into at least one or more hydrocarbon streams as well as a stream of produced water; continuously adding a non-ionic surfactant and an anionic surfactant to at least part of the stream of produced water to provide a reinjection stream; continuously injecting said reinjection stream into the subterranean formation by at least one injection well wherein the anionic surfactant is of formula R2—Y, wherein R2 is a saturated or unsaturated aliphatic or aromatic group having from 10 to 18 carbon atoms, a mean degree of unsaturation from 0 to 3, and a mean degree of branching of from 0 to 5; and wherein —Y is —O—(CH2CH(R3)O)m—(CH2CH2O)n—SO3−M+, wherein: R3 is an aliphatic or aromatic group having from 1 to 10 carbon atoms, m is from 1 to 20, n is from 0 to 5, and M+ is a monovalent cation. ### Claim 11 (depends on 10) The method of claim 10, wherein the injection well has an injectivity which is maintained or restored at a level of at least 30%, relative to its maximal injectivity. ### Claim 12 (depends on 10) The method of claim 10, wherein the total concentration of the non-ionic surfactant and anionic surfactant in the reinjection stream is less than 500 ppm, by weight. ### Claim 13 (depends on 10) The method of claim 10, wherein the non-ionic surfactant is of formula R1—X, wherein R1 is a saturated or unsaturated aliphatic or aromatic group having from 10 to 18 carbon atoms, a mean degree of unsaturation from 0 to 3, and a mean degree of branching of from 0 to 5, and X is a hydrophilic group selected from polyoxyalkylene groups, sorbitan groups, polyethoxylated sorbitan groups, polyglyceryl groups and glycosidic groups. ### Claim 14 (depends on 13) The method of claim 13, wherein —X is —O—(CH2CH2O)p—H, wherein p is from 1 to 20. ### Claim 15 (depends on 10) The method of claim 10, wherein the weight proportion of anionic surfactant relative to the total of the anionic surfactant and non-ionic surfactant in the reinjection stream is from 50 to 95%. ### Claim 16 (depends on 10) The method of claim 10, wherein the method is continuously implemented for a period of time of at least 1 month.