# US 12,110,453 B2 · Acid injection and fracturing method for porous subterranean geological formation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,110,453 B2 - Document ID: US12110453B2 - Status: Granted - Kind: B2 - Application number: 18/621,124 - Filed: 2024-03-29 - Published: 2024-08-22 - Granted: 2024-10-08 - Earliest claimed: 2019-04-29 - Assignees: King Fahd University of Petroleum and Minerals - Applicants: King Fahd University of Petroleum and Minerals - Inventors: Ime Bassey Obot; Ahmad A. Sorour - Web page: https://patentgrep.com/patent/US12110453B2 ## CPC - C09K 8/74: combined with additives added for specific purposes - C09K 8/54: Compositions for in situ inhibition of corrosion in boreholes or wells - C23F 11/04: in markedly acid liquids - C23F 11/173: Macromolecular compounds - E21B 41/02: in situ inhibition of corrosion in boreholes or wells - E21B 43/25: Methods for stimulating production {(by vibrating earth formations E21B43/003)} - C09K 2208/32: Anticorrosion additives - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - C23F: NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE (working metal by laser beams B23K26/00; desurfacing by applying flames B23K7/00; working of metal by electro-erosion B23H; producing decorative effects by removing surface material, e.g. by engraving, by etching, B44C1/22; electrolytic etching or polishing C25F); INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25 - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract A method of inhibiting corrosion of metal during acid stimulation of an oil and gas well that involves treating the oil and gas well with an acidic treatment fluid that includes 10 to 28 wt. % of an acid, based on a total weight of the acidic treatment fluid, and a corrosion inhibitor composition containing gelatin, wherein the gelatin is present in the acidic treatment fluid in a concentration of 0.1 to 10% by weight per total volume of the acidic treatment fluid. ## Claims ### Claim 1 An acid injection and fracturing method with downhole corrosion inhibition of an oil and gas well in a porous subterranean geological formation, comprising: injecting an acidic treatment fluid into the oil and gas well at a first pressure through metal tubing into pores of the porous subterranean geological formation to react with and/or dissolve rock of the porous subterranean geological formation and thereby increase a permeability of the porous subterranean geological formation; then fracturing the rock at a second pressure that is greater than the first pressure; wherein the acidic treatment fluid is an aqueous solution comprising (i) a corrosion inhibitor composition comprising gelatin and an intensifier selected from the group consisting of CuI, KI, and formic acid, and (ii) 14 to 16 wt. % of HCl, based on a total weight of the acidic treatment fluid, wherein the gelatin is present in the acidic treatment fluid in a concentration of 0.5 to 2.5 wt. % per total volume of the acidic treatment fluid, wherein the intensifier is present in the acidic treatment fluid in a concentration in a range of from 0.01 to 0.05 wt. % per total volume of the acidic treatment fluid, wherein the gelatin has a Bloom number in a range of from 50 to less than 220, and wherein the gelatin has free carboxyl groups in a range of from 78 to 115 mmol per 100 g of protein. ### Claim 2 (depends on 1) The method of claim 1, wherein the gelatin is Type A gelatin derived from acid-cured porcine skin. ### Claim 3 (depends on 1) The method of claim 1, wherein the gelatin is Type B gelatin derived from lime-cured bovine skin. ### Claim 4 (depends on 1) The method of claim 1, wherein the gelatin is Type A or Type B gelatin derived from fish skin or fish scales. ### Claim 5 (depends on 1) The method of claim 1, wherein the gelatin has a Bloom number in a range of from 150 to less than 220. ### Claim 6 (depends on 1) The method of claim 1, wherein the free carboxyl groups in the gelatin are present in a range of from 78 to 80 mmol per 100 g of protein. ### Claim 7 (depends on 1) The method of claim 1, wherein the free carboxyl groups in the gelatin are present in a range of from 100 to 115 mmol per 100 g of protein. ### Claim 8 (depends on 1) The method of claim 1, wherein the intensifier is KI. ### Claim 9 (depends on 1) The method of claim 1, wherein the corrosion inhibitor composition is substantially free of a cinnamaldehyde compound, an alkoxylated fatty amine, an imidazoline compound, and a carboxylic acid compound having 1 to 12 carbon atoms or an ester or salt thereof. ### Claim 10 (depends on 1) The method of claim 1, wherein the acidic treatment fluid is substantially free of a polysaccharide, a synthetic polymer, a quaternary ammonium surfactant, and an organic solvent. ### Claim 11 (depends on 1) The method of claim 1, wherein the HCl in the acidic treatment fluid is present in a range of from 14 to 15 wt. %. ### Claim 12 (depends on 1) The method of claim 1, wherein the oil and gas well is treated with the acidic treatment fluid at a temperature in a range of from 25 to 180° C. ### Claim 13 (depends on 1) The method of claim 1, wherein the metal tubing is carbon steel. ### Claim 14 (depends on 1) The method of claim 1, which has a corrosion inhibition efficiency of 55 to 85%. ### Claim 15 (depends on 1) The method of claim 1, wherein a corrosion rate of the metal tubing is from 12 to 36 mils penetration per year (mpy).