Method of encapsulating signaling agents for use downhole

Patent metadata

Field	Value
Publication number	US-10370578-B2
Application number	US-201815914083-A
Country	US
Kind code	B2
Filing date	Mar 7, 2018
Priority date	Mar 7, 2017
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

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.

First claim

What is claimed is:

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.

2. The method of claim 1 , where the capsules are disposed in cement in the wellbore.

3. The method of claim 1 , further comprising monitoring the concentration of the signaling agent that releases from the capsules.

4. 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.

5. The method of claim 2 , further comprising identifying a characteristic of the cement based on the step of monitoring the signaling agent.

6. 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.

7. 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.

8. The method of claim 1 , further comprising encapsulating a sealing reagent for sealing cement.

9. The method of claim 1 , where the characteristics of the polymer layers comprise permeability and yield strength.

10. 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.

11. 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.

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.

13. 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.

14. 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.

15. The method of claim 12 , where the reactive monomers comprise compounds having multi-functional reactive groups.

16. The method of claim 12 , where the fluids are selected from the group consisting of water, chloroform-cyclohexane, ethanol, and combinations thereof.

17. 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.

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.

19. The method of claim 18 , where the capsules are disposed in wellbore cement.

20. The method of claim 18 , where the characteristic of the wellbore comprises integrity of cement that lines the wellbore.

Assignees

• Saudi Arabian Oil Co

Inventors

• Contreras Elizabeth Q

Classifications

• G01N33/383

  Concrete or cement · CPC title

• C04B24/24

  Macromolecular compounds (C04B24/14 takes precedence; macromolecular compounds comprising sulfonate or sulfate groups C04B24/16) · CPC title

• C04B2103/0062

  Cross-linked polymers · CPC title

• C04B20/1033

  obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• C04B2111/80

  Optical properties, e.g. transparency or reflexibility · CPC title