# US 11,078,399 B2 · Dry blend pre-flush and spacer package and method for mixing and injecting a pre-flush and spacer on-the-fly to clean a subterranean well > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,078,399 B2 - Document ID: US11078399B2 - Status: Granted - Kind: B2 - Application number: 16/456,498 - Filed: 2019-06-28 - Published: 2020-07-23 - Granted: 2021-08-03 - Earliest claimed: 2019-01-21 - Applicants: Sanjel Energy Services Inc. - Inventors: Simon Iremonger; Jared Taylor - Web page: https://patentgrep.com/patent/US11078399B2 ## CPC - C09K 8/40: Spacer compositions, e.g. compositions used to separate well-drilling from cementing masses - C09K 8/42: Compositions for cementing, e.g. for cementing casings into boreholes; Compositions for plugging, e.g. for killing wells (compositions for plastering C09K8/50) - C09K 8/424: {using "spacer" compositions} - C09K 8/52: Compositions for preventing, limiting or eliminating depositions, e.g. for cleaning - E21B 33/13: Methods or devices for cementing, for plugging holes, crevices or the like - E21B 37/00: Methods or apparatus for cleaning boreholes or wells (E21B21/00 takes precedence) - 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 a dry blend one-part pre-flush and spacer package for forming a water-based pre-flush and spacer on-the-fly for use in a subterranean well and a method of mixing a pre-flush and spacer on-the-fly for use in a subterranean well. The dry blend pre-flush and spacer package includes an anionic surfactant, a builder compound, and optionally, a defoamer, a dispersant calcium chelator, a density modifying agent, a viscosifying agent such as a solid, and preferably rapidly hydrating, gellant, salt and one or more lost-circulation materials. The dry blend pre-flush and spacer package is mixed on-the-fly with water at the subterranean well site to form the pre-flush and spacer at a pre-selected density and the pre-flush and spacer, when pumped into the subterranean well by a pressure pumper, converts the well from an oil-wet or substantially non-water-wet condition to a substantially water-wet condition. ## Claims ### Claim 1 A dry blend pre-flush and spacer package for forming a pre-flush and spacer to clean a subterranean well, comprising: an anionic surfactant; and a builder compound; wherein the dry blend pre-flush and spacer package is mixed on-the-fly with water while being pumped into the well, the mixing being continuously at a pre-selected density, to form the pre-flush and spacer at the pre-selected density and wherein the pre-flush and spacer, when pumped into the well, converts the well from an oil-wet or substantially non-water-wet condition to a substantially water-wet condition. ### Claim 2 (depends on 1) The dry blend pre-flush and spacer package of claim 1, wherein the dry blend pre-flush and spacer package further comprises an inert density modifying agent to form the pre-flush and spacer at the pre-selected density when the dry blend pre-flush and spacer package is mixed with water. ### Claim 3 (depends on 2) The dry blend pre-flush and spacer package of claim 2, wherein the inert density modifying agent comprises one or more of silica flour, barite, flyash, calcium carbonate, hematite, flyash, manganese tetroxide, or glass microbubbles or foam. ### Claim 4 (depends on 1) The dry blend pre-flush and spacer package of claim 1, further comprising a viscosifying agent. ### Claim 5 (depends on 4) The dry blend pre-flush and spacer package of claim 4, wherein the viscosifying agent is a solid gellant. ### Claim 6 (depends on 5) The dry blend pre-flush and spacer package of claim 5, wherein the solid gellant is a rapidly hydrating gellant that comprises one or more of: hydroxyl ethyl cellulose, guar, polyvinylpyrrolidone, carboxymethylcellulose, galactomannans or other viscosifiers. ### Claim 7 (depends on 1) The dry blend pre-flush and spacer package of claim 1, further comprising a defoamer. ### Claim 8 (depends on 1) The dry blend pre-flush and spacer package of claim 1, further comprising a dispersant calcium chelator. ### Claim 9 (depends on 8) The dry blend pre-flush and spacer package of claim 8, wherein the dispersant calcium chelator comprises one or more of: citric acid, tartaric acid, sodium lignosulfonates, sodium salts of citric acid or tartaric acid, sodium acid pyrophosphate, sodium gluconate, polynaphthalene sulfonates, polycarboxylates, or polymelamine sulfonates. ### Claim 10 (depends on 1) The dry blend pre-flush and spacer package of claim 1, wherein the anionic surfactant is a low-foaming surfactant. ### Claim 11 (depends on 1) The dry blend pre-flush and spacer package of claim 1, wherein the anionic surfactant comprises one or more of: sodium myreth sulfate, sodium tripolyphosphate, ammonium lauryl sulfate, sodium lauryl sulfate (sodium dodecyl sulfate), sodium laureth sulfate (sodium lauryl ether sulfate), sodium myreth sulfate, or sodium stearate. ### Claim 12 (depends on 1) The dry blend pre-flush and spacer package of claim 1, wherein the builder compound comprises one or more of: sodium metasilicate, a hydrate of sodium metasilicate, sodium phosphates, sodium polyphosphates, sodium carbonate or soda ash. ### Claim 13 (depends on 1) The dry blend pre-flush and spacer package of claim 1, wherein the pre-flush and spacer composition is suitable for use with both cement slurry and oil-based mud (OBM). ### Claim 14 (depends on 1) The dry blend pre-flush and spacer package of claim 1, further comprising one or more lost-circulation materials. ### Claim 15 (depends on 1) The dry blend pre-flush and spacer package of claim 1, further including a salt. ### Claim 16 A method of mixing and injecting a pre-flush and spacer to clean a subterranean well, comprising: providing a dry blend pre-flush and spacer package, the dry blend pre-flush and spacer package comprising: an anionic surfactant; and a builder compound; mixing the dry blend pre-flush and spacer package with water while being pumped into the well, the mixing being continuously at a pre-selected density, to form the pre-flush and spacer at the pre-selected density; and injecting the pre-flush and spacer into the well while the mixing step continues, and converting the well from an oil-wet or substantially non-water-wet condition to a substantially water-wet condition. ### Claim 17 (depends on 16) The method of claim 16, wherein the mixing step and the injecting step are performed by a pressure pumper. ### Claim 18 (depends on 16) The method of claim 16, wherein the dry blend pre-flush and spacer package further comprises an inert density modifying agent to form the pre-flush and spacer at the pre-selected density when the dry blend pre-flush and spacer package is mixed with water. ### Claim 19 (depends on 18) The method of claim 18, wherein the inert density modifying agent comprises one or more of silica flour, barite, flyash, calcium carbonate, hematite, flyash, or manganese tetroxide. ### Claim 20 (depends on 16) The method of claim 16, wherein the dry blend pre-flush and spacer package further comprises a viscosifying agent. ### Claim 21 (depends on 20) The method of claim 20, wherein the viscosifying agent is a solid gellant. ### Claim 22 (depends on 21) The method of claim 21, wherein the solid gellant is a rapidly hydrating gellant that comprises one or more of: hydroxyl ethyl cellulose, guar, polyvinylpyrrolidone, carboxymethylcellulose, galactomannans or other viscosifiers. ### Claim 23 (depends on 16) The method of claim 16, wherein the dry blend pre-flush and spacer package further comprises a defoamer. ### Claim 24 (depends on 16) The method of claim 16, wherein the dry blend pre-flush and spacer package further comprises a dispersant calcium chelator. ### Claim 25 (depends on 24) The method of claim 24, wherein the dispersant calcium chelator comprises one or more of: citric acid, tartaric acid, sodium lignosulfonates, sodium salts of citric acid or tartaric acid, sodium acid pyrophosphate, sodium gluconate, polynaphthalene sulfonates, polycarboxylates, or polymelamine sulfonates. ### Claim 26 (depends on 16) The method of claim 16, wherein the anionic surfactant is a low-foaming surfactant. ### Claim 27 (depends on 26) The method of claim 26, wherein the anionic surfactant comprises one or more of: sodium myreth sulfate, sodium tripolyphosphate, ammonium lauryl sulfate, sodium lauryl sulfate (sodium dodecyl sulfate), sodium laureth sulfate (sodium lauryl ether sulfate), sodium myreth sulfate, or sodium stearate. ### Claim 28 (depends on 16) The method of claim 16, wherein the builder compound comprises one or more of: sodium metasilicate, a hydrate of sodium metasilicate, sodium phosphates, sodium polyphosphates, sodium carbonate or soda ash. ### Claim 29 (depends on 16) The method of claim 16, wherein the pre-flush and spacer composition is suitable for use with both cement slurry and oil-based mud (OBM). ### Claim 30 (depends on 16) The method of claim 16, wherein the dry blend pre-flush and spacer package further comprises one or more lost-circulation materials. ### Claim 31 (depends on 16) The method of claim 16, wherein the dry blend and pre-flush and spacer package further comprises a salt. ### Claim 32 (depends on 16) The method of claim 16, wherein the step of mixing the dry blend pre-flush and spacer package with water to form the pre-flush and spacer at the pre-selected density further comprises mixing the dry blend pre-flush and spacer package with a liquid gellant.