# US 2019/0375980 A1 · Scale inhibition in high pressure and high temperature applications > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0375980 A1 - Document ID: US20190375980A1 - Status: Published application - Kind: A1 - Application number: 16/483,072 - Filed: 2017-02-27 - Published: 2019-12-12 - Earliest claimed: 2017-02-27 - Assignees: Bl Technologies, Inc. - Applicants: General Electric Company - Inventors: Caroline Chihyu Sui - Web page: https://patentgrep.com/patent/US20190375980A1 ## CPC - C09K 8/035: Organic additives - C08F 220/06: Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof - C09K 8/528: inorganic depositions, e.g. sulfates or carbonates - E21B 21/068: {using chemical treatment} - E21B 37/06: using chemical means for preventing or limiting {, e.g. eliminating,} the deposition of paraffins or like substances - E21B 43/24: using heat, e.g. steam injection - E21B 43/26: by forming crevices or fractures - C09K 8/592: Compositions used in combination with generated heat, e.g. by steam injection - C09K 8/62: Compositions for forming crevices or fractures - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract Methods are provided to inhibit scale formation in oil or gas production systems. In one embodiment, the scale inhibiting treatment comprises: A) an AAA terpolymer and B) a polycarboxylate such as a polyepoxy succinic acid (PESA). The treatment can be added to these systems in the well area itself, to the well annulus and its associated tubes, casings, etc., to the oil or gas bearing subterranean formation, to injection conduits for injection of steam or fracking fluid to the subterranean formation, to the produced water, or to equipment in fluid contact with the produced water. ## Claims ### Claim 1 A method of inhibiting scale formation in an oil or gas production system comprising adding to said system a scale inhibiting treatment comprising: (A) a water soluble or dispersible polymer having the formula I wherein E is the repeat unit remaining after polymerization of an ethylenically unsaturated compound; R1 is H or lower alkyl (C1-C4); or CH2—CH2—CH2; f is an integer of about 1-100, preferably from about 1-20, X and A are independently selected and are an anionic group selected from OSO3, SO3, PO3, OPO3, or COO; G and Z are independently selected and are chosen from H or a cationic group such as Na, K, or NH4; R3 is H or lower alkyl (C1-C4), and R4 is a hydroxyl substituted alkylene radical having from 1 to about 6 carbon atoms; subscripts c, d, and e represent the molar amounts of the monomer repeat units in the polymer and wherein c is present in an amount of 1-80, d is present in an amount of 0-30 and e is present in an amount of 0-30 with the proviso that at least one of d and e is present, the sum of c+d+e=100; and (B) a polycarboxylate polymer. ### Claim 2 (depends on 1) The method as recited in claim 1, wherein (B) is a polyepoxy succinic acid (PESA). ### Claim 3 (depends on 2) The method as recited in claim 2, wherein c, d, and e are all present, wherein c is present in an amount of 1-80, d is present in an amount of 1-30, and e is present in an amount of 1-30. ### Claim 4 (depends on 3) The method as recited in claim 3, wherein a brine laden aqueous product is produced in said system, defining produced water, said method comprising adding said scale imparting treatment to said produced water. ### Claim 5 (depends on 4) The method as recited in claim 4, wherein said produced water comprises an Fe content of 3 mg/L or greater. ### Claim 6 (depends on 5) The method as recited in claim 5, wherein said produced water has a temperature of 90° C. and higher and is under a pressure of 1 Atm and greater. ### Claim 7 (depends on 6) The method as recited in claim 6, wherein said pressure is 500 psig and greater. ### Claim 8 (depends on 4) The method as recited in claim 4, wherein said produced water has a Ca content of 500 mg/L and greater. ### Claim 9 (depends on 8) The method as recited in claim 8, wherein said Ca content is 2,000 mg/L and greater. ### Claim 10 (depends on 3) The method as recited in claim 3, wherein said Fe content is 100 mg/L or greater. ### Claim 11 (depends on 2) The method as recited in claim 2, wherein said scale inhibiting treatment is fed to said produced water in an amount of about 0.1-100 mg/L (combined A and B) of said produced water. ### Claim 12 (depends on 2) The method as recited in claim 2, wherein (A) is a terpolymer comprising repeat units of i) acrylic acid or salt, ii) allylalkoxylated ether or water soluble salt, and iii) allylhydroxylated alkyl ether or water soluble salt thereof. ### Claim 13 (depends on 12) The method as recited in claim 12, wherein (A) is a terpolymer of i) acrylic acid or salt, ii) allylpolyethoxy (10) sulfonate, and iii) allylhydroxypropylsulfonate ether. ### Claim 14 (depends on 2) The method as recited in claim 2, wherein said scale inhibiting treatment is added to a well. ### Claim 15 (depends on 14) The method as recited in claim 14, wherein said scale inhibiting treatment is added to a casing or tube in operative association with said well. ### Claim 16 (depends on 2) The method as recited in claim 2, wherein said scale inhibiting treatment is added to a subterranean oil or gas bearing formation that is a component of said oil or gas production system. ### Claim 17 (depends on 16) The method as recited in claim 16, wherein said scale inhibiting treatment is added to steam or a fracking fluid that is in fluid communication with said subterranean oil or gas bearing formation. ### Claim 18 (depends on 2) The method as recited in claim 2, wherein said scale inhibiting treatment is added to produced water from said oil or gas production system. ### Claim 19 (depends on 2) The method as recited in claim 2, wherein said scale is calcium carbonate. ### Claim 20 (depends on 2) The method as recited in claim 2, wherein said scale is iron carbonate.