# US 11,299,661 B2 · Water-based drilling fluids that include lubricants > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,299,661 B2 - Document ID: US11299661B2 - Status: Granted - Kind: B2 - Application number: 16/524,724 - Filed: 2019-07-29 - Published: 2021-02-04 - Granted: 2022-04-12 - Earliest claimed: 2019-07-29 - Assignees: Saudi Arabian Oil Company - Applicants: Saudi Arabian Oil Company - Inventors: Md Amanullah; Jothibasu Ramasamy; Ali Radhwan - Web page: https://patentgrep.com/patent/US11299661B2 ## CPC - C09K 8/04: Aqueous well-drilling compositions - C09K 8/22: Synthetic organic compounds - C09K 8/16: characterised by the inorganic compounds other than clay - E21B 21/00: Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor (freeing objects stuck in boreholes by flushing E21B31/03) - E21B 21/003: {Means for stopping loss of drilling fluid (plastering the borehole wall E21B33/138)} - C09K 2208/34: Lubricant additives - 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 One or more embodiments presently described are directed to drilling fluid compositions that include lubricants, methods for making drilling fluids, and methods for drilling subterranean wells utilizing the drilling fluids. According to one embodiment, a drilling fluid composition may include a base fluid including water, a weighting agent in an amount of from 0.1 weight percent (wt. %) to 75 wt. % relative to the total weight of the water-based drilling fluid, and a lubricant in an amount of from 1 wt. % to 10 wt. % relative to the total weight of the water-based drilling fluid. The lubricant may include one or more alkyl esters and a fatty acid blend including at least palmitic acid and stearic acid. The sum of the weight percent of the palmitic acid and stearic acid may be at least 50 wt. % of the fatty acid blend. ## Claims ### Claim 1 A water-based drilling fluid comprising: a base fluid comprising water; a weighting agent in an amount of from 0.1 wt. % to 75 wt. % relative to the total weight of the water-based drilling fluid; and a lubricant in an amount of from | wt. % to 10 wt. % relative to the total weight of the water-based drilling fluid, the lubricant comprising: one or more alkyl esters; and a fatty acid blend comprising at least palmitic acid and stearic acid, where the sum of the weight percent of the palmitic acid and stearic acid is at least 50 wt. % of the fatty acid blend, and where the weight ratio of the one or more alkyl esters to the fatty acid blend is from 1:1 to 3:1, wherein the weight ratio uniformly distributes the fatty acid blend within the one or more alkyl esters so that the lubricant is in a liquid state. ### Claim 2 (depends on 1) The water-based drilling fluid of claim 1, further comprising at least one salt selected from a monovalent salt, a divalent salt, or combinations of these. ### Claim 3 (depends on 2) The water-based drilling fluid of claim 2, where the at least one salt is present in an amount from 0.01 wt. % to 10 wt. % relative to the total weight of the water-based drilling fluid. ### Claim 4 (depends on 2) The water-based drilling fluid of claim 2, where the at least one salt is selected from KCl, NaCl, CaCl2), or combinations of these. ### Claim 5 (depends on 1) The water-based drilling fluid of claim 1, where the molar ratio of palmitic acid to stearic acid is from 20:80 to 40:60. ### Claim 6 (depends on 1) The water-based drilling fluid of claim 1, where the one or more alkyl esters are derived from vegetable oil. ### Claim 7 (depends on 1) The water-based drilling fluid of claim 1, wherein the lubricant comprises from 55 wt. % to 75 wt. % alkyl esters based on the total weight of the lubricant. ### Claim 8 (depends on 1) The water-based drilling fluid of claim 1, wherein the lubricant comprises: from 55 wt. % to 75 wt. % alkyl esters based on the total weight of the lubricant; and from 25 wt. % to 45 wt. % fatty acid blend based on the total weight of the lubricant. ### Claim 9 (depends on 8) The water-based drilling fluid of claim 8, where the molar ratio of palmitic acid to stearic acid is from 20:80 to 40:60. ### Claim 10 A method for making a water-based drilling fluid, the method comprising: mixing a base fluid, a weighting agent in an amount of from 0.1 wt. % to 75 wt. % relative to the total weight of the water-based drilling fluid, and a lubricant in an amount of from 1 wt. % to 10 wt. % relative to the total weight of the water-based drilling fluid, where: the base fluid comprises water; the lubricant comprises one or more alkyl esters and a fatty acid blend comprising at least palmitic acid and stearic acid; the sum of the weight percent of the palmitic acid and stearic acid is at least 50 wt. % of the fatty acid blend; and the weight ratio of the one or more alkyl esters to the fatty acid blend is from 1:1 to 3:1, wherein the weight ratio uniformly distributes the fatty acid blend within the one or more alkyl esters so that the lubricant is in a liquid state. ### Claim 11 (depends on 10) The method of claim 10, where the mixing step further comprises mixing at least one salt selected from a monovalent salt, a divalent salt, or combinations of these. ### Claim 12 (depends on 11) The method of claim 11, where the at least one salt is present in an amount from 0.01 wt. % to 10 wt. % relative to the total weight of the water-based drilling fluid. ### Claim 13 (depends on 11) The method of claim 11, where the at least one salt is selected from KCl, NaCl, CaCl2, or combinations of these. ### Claim 14 (depends on 10) The method of claim 10, where the molar ratio of the solid palmitic acid to the solid stearic acid is from 20:80 to 50:50. ### Claim 15 (depends on 10) The method of claim 10, where the one or more alkyl esters are derived from vegetable oil. ### Claim 16 (depends on 10) The method of claim 10, further comprising: mixing solid palmitic acid and solid stearic acid to make a solid fatty acid blend; heating the solid fatty acid blend to form a liquid fatty acid blend; mixing the liquid fatty acid blend with one or more alkyl esters to from a lubricant precursor; and heating the lubricant precursor to a temperature of at least 50° C. and mechanically agitating the lubricant precursor while heating to form the lubricant. ### Claim 17 A method for drilling a subterranean well, the method comprising: operating a drill in a wellbore in the presence of a water-based drilling fluid, where the water-based drilling fluid comprises: a base fluid comprising water; a weighting agent in an amount of from 0.1 wt. % to 75 wt. % relative to the total weight of the water-based drilling fluid; and a lubricant in an amount of from 1 wt. % to 10 wt. % relative to the total weight of the water-based drilling fluid, the lubricant comprising: one or more alkyl esters; and a fatty acid blend comprising at least palmitic acid and stearic acid, where the sum of the weight percent of the palmitic acid and stearic acid is at least 50 wt. % of the fatty acid blend, and the weight ratio of the one or more alkyl esters to the fatty acid blend is from 1:1 to 3:1, wherein the weight ratio uniformly distributes the fatty acid blend within the one or more alkyl esters so that the lubricant is in a liquid state. ### Claim 18 (depends on 17) The method of claim 17, where the water-based drilling fluid further comprises at least one salt selected from a monovalent salt, a divalent salt, or combinations of these. ### Claim 19 (depends on 18) The method of claim 18, where the at least one salt is present in an amount from 0.01 wt. % to 10 wt. % relative to the total weight of the base fluid. ### Claim 20 (depends on 18) The method of claim 18, where the at least one salt is selected from KCl, NaCl, CaCl2, or combinations of these. ### Claim 21 (depends on 17) The method of claim 17, where the molar ratio of palmitic acid to stearic acid is from 20:80 to 40:60. ### Claim 22 (depends on 17) The method of claim 17, where the one or more alkyl esters are derived from vegetable oil.