Self-repairing cement including microcapsule-in-microcapsule material and designed swellable rubber and methods for fabricating same

Patent metadata

Field	Value
Publication number	US-12297148-B2
Application number	US-202117453297-A
Country	US
Kind code	B2
Filing date	Nov 2, 2021
Priority date	Nov 2, 2021
Publication date	May 13, 2025
Grant date	May 13, 2025

Abstract

Microcapsule encapsulated microcapsule (MIM) material compositions and methods for preparing the same are provided for self-repairing cements that include a plurality of first microcapsules where each of the first microcapsule comprises a first core and a first shell and a plurality of second microcapsules that each comprise a second core and a second shell where the plurality of second microcapsules are dispersed within a continuous phase comprised within the first core of each of the first microcapsules. The MIM material may be prepared such that the first and second shell comprise a cross-linked material. Compositions for self-healing cement slurries are also provided and include cement, sand, water, and microcapsule encapsulated microcapsules (MIM) materials.

First claim

What is claimed:

1. A microcapsule encapsulated microcapsule (MIM) material for self-repairing cement comprising:
a plurality of first microcapsules wherein each of the first microcapsule comprises a first core and a first shell;
a plurality of second microcapsules that each comprise a second core and a second shell;
wherein the plurality of second microcapsules are dispersed within a continuous phase comprised within the first core of each of the first microcapsules,
wherein each of the first and second shell comprise a polyurethane cross-linked material,
wherein the continuous phase of the first core comprises a dissolved isocyanate compound in a hydrophobic media.

2. The MIM material of claim 1 , wherein the plurality of second microcapsules comprise water, a polyol, and a surfactant.

3. The MIM material of claim 1 , wherein each of the first microcapsules have a diameter ranging from 10 μm to 500 μm.

4. The MIM material of claim 3 , wherein the MIM material comprises first microcapsules of more than one diameter such that a particle diameter size distribution of the first microcapsules of the MIM materials is one or more selected from group consisting of from 10 to 150 μm, from 150 to 300 μm, from 300 to 500 μm, or a combination thereof.

5. The MIM material of claim 1 , wherein the continuous phase of the first core comprises the dissolved isocyanate compound selected from the group consisting of diisocyanate, methylene diphenyl diisocyanate (MDI), hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), hydrogenate MDI, hexahydrotoluylene diisocyanate (H6TDI), trimethyl hexamethylene diisocyanate, tetramethyl xylylene isocyanate, tetramethyl xylylene diisocyanate, xylylene diisocyanate, isocyanate dimers, isocyanate trimers, polyisocyanates, polydiisocyanates, or combinations thereof.

6. The MIM material of claim 1 , where the continuous phase of the first core comprises the dissolved isocyanate compound in an amount ranging from 40 to 70 wt. %, relative to the weight of the entire MIM material.

7. The MIM material of claim 2 , wherein the polyol is one or more of a diol, a triol, and a polyol having four reactive hydroxyl groups.

8. The MIM material of claim 2 , wherein the first core of the MIM material comprises a liquid polyisocyanate or a dissolved polyisocyanate.

9. The MIM material of claim 8 , wherein equivalents of the liquid polyisocyanate or dissolved polyisocyanates and polyols may be contained within their respective first and second cores in a ratio, relative to each other, ranging from 0.9:1 to 1:1.1.

10. The MIM material of claim 7 , wherein the diol is selected from the group consisting of 1,4-butanediol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, tripropylene glycol, 1,3-propanediol, 1,3-butanediol, neopentyl glycol, 1,6-hexanediol, and 1,4-cyclohexanedimethanol.

11. The MIM material of claim 2 , wherein a surfactant is contained within both the first and second cores.

12. A method for forming a microcapsule encapsulated microcapsule (MIM) material for self-repairing cement, the method comprising:
forming a water-in-oil emulsion containing an aqueous phase dispersed within a hydrophobic media continuous phase, wherein the aqueous dispersed phase comprises a mixture of polyol compounds, and wherein the continuous phase is comprised of a solvent;
adding a mixture of a prepolymer and a dissolved isocyanate or liquid isocyanate compound to the water-in-oil emulsion;
polymerizing the prepolymer in a first stage polymerization reaction with the polyol via interfacial polymerization to form a polymeric microcapsule shell, encapsulating the liquid polyol compound in the formed polymeric microcapsule and thereby producing a plurality of second microcapsules;
forming a second water-in-oil-in-water emulsion, wherein the continuous phased is comprised of an aqueous solution, and wherein the dispersed phase is comprised of the water-in-oil emulsion comprising the produced plurality of second microcapsules;
adding a second quantity of the prepolymer and the liquid isocyanate compound to an aqueous solution containing a surfactant; and
adding a cross-linker to polymerize the prepolymer in a second stage polymerization reaction with the cross-linker via interfacial polymerization to form a larger polymeric microcapsule shell, encapsulating the liquid isocyanate compound and the plurality of second microcapsules in the formed polymeric microcapsule and thereby producing a plurality of first microcapsules.

13. The method of claim 12 , wherein a surfactant is added during the formation of each of the first water-in-oil emulsion and second water-in-oil-in-water emulsion and is contained within both the first and second microcapsules.

14. The method of claim 12 , wherein each of the first and second stage polymerization reactions are conducted at a temperature in a range from 125° F. to 225° F.

15. The method of claim 12 , wherein in the first stage emulsion polymerization reaction, the amount of the hydrophobic media continuous phase is present in an amount in a range from 60 wt % to 90 wt % of the water-in-oil emulsion.

16. The method of claim 12 , wherein in the second stage emulsion polymerization reaction, the amount of the aqueous solution may be present in an amount in a range from 60 wt % to 90 wt % of the water-in-oil-in-water emulsion.

17. A self-healing cement slurry comprising:
cement;
sand;
water; and
microcapsule encapsulated microcapsules (MIM) material comprising:
a plurality of first microcapsules comprising a first core and a first shell;
a plurality of second microcapsules that each comprise a second core and a second shell;
wherein the plurality of second microcapsules are dispersed in a continuous phase within the first core of the first microcapsule,
wherein both the first and second shell are comprised of a polyurethane cross-linked material; and
wherein the cement slurry comprises the MIM material in an amount ranging from 1 to 50% by weight, relative to the entire weight of the cement slurry,
wherein the continuous phase of the first core comprises a dissolved isocyanate compound in a hydrophobic media.

18. The self-healing cement of claim 17 , wherein the cement slurry comprises the MIM material in an amount in a range from 1 to 20% by weight, relative to the entire weight of the cement slurry.

19. The self-healing cement of claim 17 , wherein the cement slurry further comprises a swellable micronized rubber additive.

20. The self-healing cement of claim 19 , wherein the swellable micronized rubber additive is a water-swellable micronized rubber additive comprising one or more compounds selected from the group consisting of isobutylene maleic anhydride, acrylic acid-type polymers, polyethylene oxide polymers, bentonite, or mixtures thereof.

21. The self-healing cement of claim 19 , wherein the swellable micronized rubber additive is an oil-swellable micronized rubber additive comprising one or more compounds selected from the group consisting of nitrile rubber, styrene butadiene, and fluoro-silicones.

22. The self-healing cement of claim 19 , wherein the swellable micronized rubber additive is comprised in an amount from 1 to 40 wt. % relative to the entire weight of the cement slurry.

Assignees

• Saudi Arabian Oil Co

Inventors

• Orlov Maxim
• Al-Yami Abdullah S
• Baltaeva Madina

Classifications

• C04B2111/00663

  as filling material for cavities or the like · CPC title

• C04B28/04

  Portland cements · CPC title

• C04B20/0036

  Microsized or nanosized · CPC title

• C04B24/125

  Compounds containing one or more carbon-to-nitrogen double or triple bonds, e.g. imines · CPC title

• C04B2103/0049

  Water-swellable polymers · CPC title