# US 10,370,578 B2 · Method of encapsulating signaling agents for use downhole > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,370,578 B2 - Document ID: US10370578B2 - Status: Granted - Kind: B2 - Application number: 15/914,083 - Filed: 2018-03-07 - Published: 2018-09-13 - Granted: 2019-08-06 - Earliest claimed: 2017-03-07 - Assignees: Saudi Arabian Oil Company - Applicants: Saudi Arabian Oil Company - Inventors: Elizabeth Q. Contreras - Web page: https://patentgrep.com/patent/US10370578B2 ## CPC - C09K 8/467: containing additives for specific purposes - B01J 13/16: Interfacial polymerisation - C04B 20/1033: {obtained by reactions only involving carbon-to-carbon unsaturated bonds} - C04B 24/24: Macromolecular compounds (C04B24/14 takes precedence; macromolecular compounds comprising sulfonate or sulfate groups C04B24/16) - C04B 28/02: containing hydraulic cements other than calcium sulfates - E21B 33/14: for cementing casings into boreholes - E21B 47/005: Monitoring or checking of cementation quality or level - G01N 33/383: {Concrete or cement} - C04B 2103/0058: {Core-shell polymers} - C04B 2103/0062: {Cross-linked polymers} - C04B 2103/54: Pigments; Dyes - C04B 2111/80: Optical properties, e.g. transparency or reflexibility - C04B 2111/807: {Luminescent or fluorescent materials} - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract A method of monitoring conditions in a wellbore by disposing capsules with a signaling agent downhole, and monitoring the presence of the signaling agent released from the capsules that escape the wellbore. The capsules are formed by combining immiscible liquids, where one of the liquids contains the signaling substance, and each of the liquids contains a reagent. When combined, the liquids segregate into a dispersed phase and a continuous phase, with the dispersed phase having the signaling agent. The reagents react at the interfaces between dispersed and continuous phases and form polymer layers encapsulating the signaling agent to form the capsules. When disposed downhole, such as in casing cement, the capsule membranes can burst under pressure or temperature to release the signaling agent. Adjusting relative concentrations of the reagents varies membrane strength and permeability. ## Claims ### Claim 1 A method of wellbore operations comprising: providing a first fluid having a signaling agent and a first reagent; providing a second fluid that is immiscible with the first fluid and that contains a second reagent that is combinable with the first reagent to form a polymer; combining the first and second fluids so that the first fluid is dispersed in the second fluid to form vesicles of the first fluid in the second fluid, and so that the first and second reagents react at interfaces between the first and second fluids to form polymer layers that encapsulate the vesicles, and which form capsules containing the signaling agent; controlling a characteristic of the polymer layers by adjusting a concentration of a one of the first and second reagents; disposing the capsules in a wellbore; and monitoring for the presence of signaling agents that escape from the capsules. ### Claim 2 (depends on 1) The method of claim 1, where the capsules are disposed in cement in the wellbore. ### Claim 3 (depends on 1) The method of claim 1, further comprising monitoring the concentration of the signaling agent that releases from the capsules. ### Claim 4 (depends on 2) The method of claim 2, where the signaling agent comprises a first signaling agent, the method comprising forming capsules having a second signaling agent and disposing the capsules having the second signaling agent at a designated depth in the wellbore that is different from a depth where capsules having the first signaling agent are disposed in the wellbore. ### Claim 5 (depends on 2) The method of claim 2, further comprising identifying a characteristic of the cement based on the step of monitoring the signaling agent. ### Claim 6 (depends on 1) The method of claim 1, where the signaling agent comprises a material selected from the group consisting of a dye, a fluorophore, an isotope, and combinations thereof. ### Claim 7 (depends on 1) The method of claim 1, where the first and second reagents comprise compounds having a reactive functional group and are selected from the group consisting of monomers with tri-functional acid chlorides and monomers with di-functional amino groups. ### Claim 8 (depends on 1) The method of claim 1, further comprising encapsulating a sealing reagent for sealing cement. ### Claim 9 (depends on 1) The method of claim 1, where the characteristics of the polymer layers comprise permeability and yield strength. ### Claim 10 (depends on 1) The method of claim 1, where the polymer layers are formulated to fail at one of a designated pressure, a designated temperature, or a designated temperature and designated pressure. ### Claim 11 (depends on 1) The method of claim 1, further comprising controlling a release rate of the signaling agent from the polymer layers by adjusting one or more of, a viscosity of the first fluid, a permeability of the polymer layers, a size of the reagents, and a charge of the reagents. ### Claim 12 A method of wellbore operations comprising: combining first and second solutions that each comprise a reactive monomer and a fluid that is immiscible with a fluid in the other solution, and at least one of the first or second solutions having a signaling agent; forming an emulsion with the first and second solutions that comprises a continuous phase, and amounts of a dispersed phase containing the signaling agent and distributed within the continuous phase; forming polymeric layers around the amounts of the dispersed phase by reacting monomers that define capsules containing the signaling agent; adjusting a concentration of a one of the reactive monomers to adjust a characteristic of polymer layers; disposing the capsules in, cement that lines a wellbore; and evaluating a condition of the cement by sensing signaling agent that has escaped from the capsules in the cement. ### Claim 13 (depends on 12) The method of claim 12, where the step of evaluating comprises using colorimetric spectroscopy, infrared spectroscopy, mass spectroscopy, visual inspection, a radiation detector, and combinations thereof. ### Claim 14 (depends on 12) The method of claim 12, where the emulsion is selected from a group comprising a water in oil emulsion, an oil in water emulsion, an oil in oil emulsion, and a water in water emulsion. ### Claim 15 (depends on 12) The method of claim 12, where the reactive monomers comprise compounds having multi-functional reactive groups. ### Claim 16 (depends on 12) The method of claim 12, where the fluids are selected from the group consisting of water, chloroform-cyclohexane, ethanol, and combinations thereof. ### Claim 17 (depends on 12) The method of claim 12, where the signaling agent is selected from the group consisting of colored dyes, fluorophore, isotopes, fluorescent dyes, fluorescein, and combinations thereof. ### Claim 18 A method of wellbore operations comprising: using an interfacial polymerization technique that comprises combining a monomer with a cross-linking monomer to form capsules that comprise a signaling agent disposed within a polymer layer; adjusting an amount of the cross-linking monomer to control a characteristic of the polymer layer; disposing the capsules in a wellbore; and assessing a characteristic of the wellbore based on sensing the signaling agent escaping the capsules. ### Claim 19 (depends on 18) The method of claim 18, where the capsules are disposed in wellbore cement. ### Claim 20 (depends on 18) The method of claim 18, where the characteristic of the wellbore comprises integrity of cement that lines the wellbore.