# US 8,273,690 B2 · Crosslinkable polymer compositions comprising phenols and associated methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,273,690 B2 - Document ID: US8273690B2 - Status: Granted - Kind: B2 - Application number: 11/592,484 - Filed: 2006-11-03 - Published: 2007-03-08 - Granted: 2012-09-25 - Earliest claimed: 2005-06-28 - Assignees: Halliburton Energy Services, Inc. - Inventors: B. Raghava Reddy; Julio E. Vasquez; Larry S. Eoff; Eldon Dwyann Dalrymple - Web page: https://patentgrep.com/patent/US8273690B2 ## CPC - C09K 8/5083: {obtained by reactions only involving carbon-to-carbon unsaturated bonds} - C09K 8/512: containing cross-linking agents - C09K 8/514: of natural origin, e.g. polysaccharides, cellulose (C09K8/512 takes precedence) - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE ## Abstract Crosslinkable-polymer compositions that comprise a chitosan-based compound and a phenol source, and associated methods, are provided. Various methods of use are also provided. In one embodiment, the methods comprise providing a crosslinkable-polymer composition comprising an aqueous fluid, a chitosan-based compound, a chitosan-reacting polymer, and a phenol source; introducing the crosslinkable-polymer composition into the portion of the subterranean formation; and allowing the crosslinkable-polymer composition to form a crosslinked gel in the portion of the subterranean formation. ## Claims ### Claim 1 A crosslinkable-polymer composition, comprising: an aqueous fluid; a chitosan-based compound and a chitosan-reacting polymer wherein a crosslink is formed between the chitosan-based compound and the chitosan-reacting polymer; a phenol source selected from the group consisting of a phenolic compound, a compound that produces a phenolic compound, and combinations thereof; wherein the phenolic compound is selected from the group consisting of a vanillin, vanilic acid, tyrosine, an alpha-hydroxynapthalene, a beta-hydroxynapthalene, and combinations thereof; wherein the compound that produces a phenolic compound is selected from the group consisting of acetyl salicyclic acid, para-nitrophenyl acetate, tris(nonlphenylphosphite), triphenylphosphite, and combinations thereof; and, a gelation-retarding additive. ### Claim 2 (depends on 1) The crosslinkable-polymer composition of claim 1 wherein the aqueous fluid comprises an acid selected from the group consisting of organic acids, inorganic acids, and mixtures thereof. ### Claim 3 (depends on 1) The crosslinkable-polymer composition of claim 1 wherein the chitosan-based compound is present in an amount in the range of from about 0.05% to about 5% by weight of the crosslinkable-polymer composition. ### Claim 4 (depends on 1) The crosslinkable-polymer composition of claim 1 wherein the chitosan-reacting polymer is present in an amount in the range of from about 0.5% to about 20% by weight of the crosslinkable-polymer composition. ### Claim 5 (depends on 1) The crosslinkable-polymer composition of claim 1 wherein the chitosan-reacting polymer comprises a carbonyl group. ### Claim 6 (depends on 1) The crosslinkable-polymer composition of claim 1 wherein the chitosan-reacting polymer comprises an acrylamide-based polymer. ### Claim 7 (depends on 1) The crosslinkable-polymer composition of claim 1 wherein the chitosan-reacting polymer is selected from the group consisting of a polyacrylamide, an acrylamide copolymer, polyvinyl pyrrolidone, a 2-acrylamido-2-methylpropane sulfonic acid/acrylamide copolymer, a sulfonated styrene/maleic anhydride copolymer, a vinylpyrrolidone/2-acrylamido-2-methylpropane sulfonic acid/acrylamide terpolymer, a 2-acrylamido-2-methylpropane sulfonic acid/N-N-dimethylacrylamide/acrylamide terpolymer, a polyketone, a acrylamide/t-butyl acrylate copolymer, an oxidized polyvinyl alcohol, a poly(lactic acid), a water soluble polyester, a water dispersible polyester, a derivative thereof, and a combination thereof. ### Claim 8 (depends on 1) The crosslinkable-polymer composition of claim 1 wherein the chitosan-reacting polymer comprises an oxidized polysaccharide. ### Claim 9 (depends on 1) The crosslinkable-polymer composition of claim 1 wherein the chitosan-reacting polymer comprises a starch. ### Claim 10 (depends on 1) The crosslinkable-polymer composition of claim 1 wherein the phenol source is a polyhydric phenol. ### Claim 11 (depends on 1) The crosslinkable-polymer composition of claim 1 wherein the gelation-retarding additive is present in an amount in the range of from about 0.1% to about 10% by weight of the crosslinkable-polymer composition. ### Claim 12 (depends on 1) The crosslinkable-polymer composition of claim 1 wherein the gelation-retarding additive is selected from the group consisting of: carboxylic acid anhydrides, organic sulfonic acid derivatives, and mixtures thereof. ### Claim 13 (depends on 1) The crosslinkable-polymer composition of claim 1 wherein the crosslinkable polymer composition is thermally stable in downhole temperatures. ### Claim 14 A crosslinkable-polymer composition comprising: an aqueous fluid present in an amount in the range of from about 65% to about 99.4% by weight of the crosslinkable-polymer composition; a chitosan-reacting polymer present in an amount in the range of from about 0.5% to about 20% by weight of the crosslinkable-polymer composition and a chitosan-based compound present in an amount in the range of from about 0.05% to about 5% by weight of the crosslinkable-polymer composition wherein a crosslink is formed between the chitosan-based compound and the chitosan-reacting polymer; a phenol source present in an amount in the range of from about 1.25% to about 3.0% by weight of the crosslinkable-polymer composition; wherein the phenol source is selected from the group consisting of a phenolic compound, a compound that produces a phenolic compound, and combinations thereof wherein the phenolic compound is selected from the group consisting of a vanillin, vanilic acid, tyrosine, an alpha-hydroxynapthalene, a beta-hydroxynapthalene, and combinations thereof; wherein the compound that produces a phenolic compound is selected from the group consisting of acetyl salicyclic acid, para-nitrophenyl acetate, tris(nonlphenylphosphite), triphenylphosphite, and combinations thereof; and, a gelation-retarding additive present in an amount in the range of from about 0.1% to about 10% by weight of the crosslinkable-polymer composition. ### Claim 15 A crosslinkable-polymer composition, comprising: an aqueous fluid; a chitosan-based compound and a polymer comprising a carbonyl group capable of interacting with the chitosan-based compound wherein a crosslink is formed between the chitosan-based compound and the polymer comprising a carbonyl group; a phenol source selected from the group consisting of a phenolic compound, a compound that produces a phenolic compound, and combinations thereof; wherein the phenolic compound is selected from the group consisting of a vanillin, vanilic acid, tyrosine, an alpha-hydroxynapthalene, a beta-hydroxynapthalene, and combinations thereof; wherein the compound that produces a phenolic compound is selected from the group consisting of acetyl salicyclic acid, para-nitrophenyl acetate, tris(nonlphenylphosphite), triphenylphosphite, and combinations thereof; and, a gelation-retarding additive. ### Claim 16 (depends on 15) The crosslinkable-polymer composition of claim 15: wherein the aqueous fluid is present in an amount in the range of from about 65% to about 99.4% by weight of the crosslinkable-polymer composition; wherein the polymer is present in an amount in the range of from about 0.5% to about 20% by weight of the crosslinkable-polymer composition; wherein the chitosan-based compound is present in an amount in the range of from about 0.05% to about 5% by weight of the crosslinkable-polymer composition; and wherein the phenol source is present in an amount in the range of from about 1.25% to about 3.0% by weight of the crosslinkable-polymer composition. ### Claim 17 (depends on 15) The crosslinkable-polymer composition of claim 15 wherein the polymer comprises an acrylamide/t-butyl acrylate copolymer. ### Claim 18 (depends on 15) The crosslinkable-polymer composition of claim 15 wherein the phenol source is a polyhydric phenol. ### Claim 19 (depends on 14) The crosslinkable-polymer composition of claim 14 wherein the chitosan-reacting polymer comprises an acrylamide/t-butyl acrylate copolymer. ### Claim 20 (depends on 14) The crosslinkable-polymer composition of claim 14 wherein the phenol source is a polyhydric phenol.