# US 2013/0153226 A1 · Method for Delayedly Crosslinking Environmentally Friendly Fluids > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0153226 A1 - Document ID: US20130153226A1 - Status: Published application - Kind: A1 - Application number: 13/329,844 - Filed: 2011-12-19 - Published: 2013-06-20 - Earliest claimed: 2011-12-19 - Assignees: Halliburton Energy Services, Inc. - Inventors: Melissa Weston; Jeremy Holtsclaw; David Loveless - Web page: https://patentgrep.com/patent/US20130153226A1 ## CPC - C09K 8/685: {containing cross-linking agents} - C09K 8/08: containing natural organic compounds, e.g. polysaccharides, or derivatives thereof - C09K 8/12: containing synthetic organic macromolecular compounds or their precursors - C09K 8/887: {containing cross-linking agents} - C09K 8/90: of natural origin, e.g. polysaccharides, cellulose - E21B 43/26: by forming crevices or fractures - 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 ## Abstract The present invention relates to environmentally friendly delayed crosslinking complexes that are useful in subterranean treatment fluids. One embodiment of the present invention provides a method of providing a treatment fluid having a first viscosity and includes: an aqueous base fluid, a viscosifying agent, a delayed crosslinking complex having: a metal and a ligand, the ligand having at least one hydroxyl group and at least one carboxylic acid group; and placing the treatment fluid in a subterranean formation. In some embodiments, the delayed crosslinking complex is compliant and/or the viscosifying agent is compliant. ## Claims ### Claim 1 A method comprising: providing a treatment fluid having a first viscosity comprising: an aqueous base fluid, a viscosifying agent, a delayed crosslinking complex comprising: a metal and a ligand, the ligand comprising at least one hydroxyl group and at least one carboxylic acid group; and placing the treatment fluid in a subterranean formation. ### Claim 2 (depends on 1) The method of claim 1 wherein the delayed crosslinking complex crosslinks the viscosifying agent to form a crosslinked gel after the treatment fluid is placed in the subterranean formation so as to form a viscosified treatment fluid having a second viscosity, the second viscosity being higher than the first viscosity prior to being placed in the subterranean formation. ### Claim 3 (depends on 2) The method of claim 2 wherein the crosslinked gel having a second viscosity is formed at a variable time from about 1 minute to about 10 minutes after placing the treatment fluid in the subterranean formation. ### Claim 4 (depends on 1) The method of claim 1 wherein the delayed crosslinking complex delays the treatment fluid from forming a crosslinked gel having a second viscosity, the second viscosity being higher than the first viscosity after being placed in the subterranean formation. ### Claim 5 (depends on 1) The method of claim 1 wherein the delayed crosslinking complex includes a ligand selected from the group consisting of: a gluconate, a malate, a picolanate, a lactate, a citrate, an acetate, a tartrate, any derivatives thereof, and any combination thereof. ### Claim 6 (depends on 1) The method of claim 1 wherein the viscosifying agent comprises a viscosifying agent selected from the group consisting of: a xanthan, an acrylate, a methacrylate, a vinyl phosphate, an acrylamide, a carboxyethylcellulose, a carboxymethylcellulose, a carboxymethylhydroxyethylcellulose, a carboxymethylhydroxypropyl guar, a carboxymethyl guar, any derivative thereof, and any combination thereof. ### Claim 7 (depends on 1) The method of claim 1 wherein the delayed crosslinking complex includes a metal ion selected from the group consisting of: an aluminum ion, a zirconium ion, an iron ion, a titanium ion, a chromium ion, an antimony ion, and any combination thereof. ### Claim 8 (depends on 1) The method of claim 1 wherein the treatment fluid has a pH in the range of from about 4.8 to about 5.6. ### Claim 9 (depends on 1) The method of claim 1 wherein the treatment fluid comprises a treatment fluid selected from the group consisting of: a fracturing fluid, a gravel packing fluid, a completion fluid, a drilling fluid, and any combination thereof. ### Claim 10 A method comprising: providing a treatment fluid having a first viscosity comprising: an aqueous base fluid, a viscosifying agent, and a delayed crosslinking complex; placing the treatment fluid in a subterranean formation; and crosslinking the viscosifying agent with the delayed crosslinking complex, wherein the delayed crosslinking complex is compliant. ### Claim 11 (depends on 10) The method of claim 10 wherein the delayed crosslinking complex crosslinks the viscosifying agent to form a crosslinked gel after the treatment fluid is placed in the subterranean formation so as to form a viscosified treatment fluid having a second viscosity, the second viscosity being higher than the first viscosity prior to being placed in the subterranean formation. ### Claim 12 (depends on 10) The method of claim 10 wherein the crosslinked gel having a second viscosity is formed at a variable time from about 1 minute to about 10 minutes after placing the treatment fluid in the subterranean formation. ### Claim 13 (depends on 10) The method of claim 10 wherein the delayed crosslinking complex delays the treatment fluid from forming a crosslinked gel having a second viscosity, the second viscosity being higher than the first viscosity after being placed in the subterranean formation. ### Claim 14 (depends on 10) The method of claim 10 wherein the delayed crosslinking complex includes a gluconate, a malate, a picolanate, a lactate, a citrate, an acetate, a tartrate, any derivatives thereof, and any combination thereof. ### Claim 15 (depends on 10) The method of claim 10 wherein the crosslinking agent comprises a compound capable of supplying a metal ion selected from the group consisting of: an aluminum ion, a zirconium ion, an iron ion, a titanium ion, a chromium ion, an antimony ion, and any combination thereof. ### Claim 16 (depends on 10) The method of claim 10 wherein treatment fluid has a pH in the range of from about 4.8 to about 5.6. ### Claim 17 (depends on 10) The method of claim 10 wherein the treatment fluid comprises a treatment fluid selected from the group consisting of: a fracturing fluid, a gravel packing fluid, a completion fluid, a drilling fluid, and any combination thereof. ### Claim 18 A method comprising: providing a viscosified treatment fluid in a subterranean formation, the viscosified treatment fluid comprising: an aqueous base fluid, a crosslinked gel, and a ligand selected from the group consisting of: a gluconate, a malate, a picolanate, a lactate, a citrate, an acetate, a tartrate, any derivatives thereof, and any combination thereof. ### Claim 19 (depends on 18) The method of claim 18 wherein the crosslinked gel is formed from at least one monomer selected from the group consisting of: a xanthan, an acrylate, a methacrylate, a vinyl phosphate, an acrylamide, a carboxyethylcellulose, a carboxymethylcellulose, a carboxymethylhydroxyethylcellulose, a carboxymethylhydroxypropyl guar, a carboxymethyl guar, any derivative thereof, and any combination thereof. ### Claim 20 (depends on 18) The method of claim 18 wherein the viscosified treatment fluid comprises a treatment fluid selected from the group consisting of: a fracturing fluid, a gravel packing fluid, a completion fluid, a drilling fluid, and any combination thereof.