Carbon dioxide self-healing material as well as preparation method and application thereof

Abstract

The invention provides a carbon dioxide self-healing material as well as a preparation method and application thereof. The carbon dioxide self-healing material comprises a base material and a coating material coating the surface of the base material, the base material is prepared from the following raw materials: an acrylamide monomer, a first acrylate monomer and a first carbon dioxide responsive compound; the coating material is prepared from the following raw materials: a second acrylate monomer and a second carbon dioxide responsive compound. The carbon dioxide self-healing material has excellent mechanical performance and good adhesion performance with an inorganic interface, can improve the gas channeling resistance of cement and regulate the thickening performance of the cement, has good responsiveness to carbon dioxide, can realize cement self-repairing, prevents the corrosion of carbon dioxide to the cement, and has a good application prospect. And oil and gas channeling caused by microcracks in set cement can be effectively prevented and controlled.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of oil field plugging, and particularly relates to a carbon dioxide self-healing material and a preparation method and application thereof. BACKGROUND

[0002] With the further increase of carbon dioxide emissions, great threat is caused to the ecological environment. Effectively solving the problem of carbon dioxide emissions is of great significance for mitigating the greenhouse effect. Among them, carbon dioxide capture, utilization and storage (CCUS) has become one of the indispensable key technologies. CCUS technology refers to collecting and storing CO2 in the atmosphere to reduce the concentration of CO2 in the atmosphere, and is a measure that can effectively reduce carbon emissions.

[0003] The geological storage system of CO2 is composed of a stainless steel casing, cement, a cap rock and a cement plug; and the failure of wellbore integrity is the main leakage path of CO2 in geological storage; in the process of oil and gas development, due to the inherent brittleness of cement material, microcracks will inevitably be formed under the action of internal stress and external load, and with the passage of time, the interlayer integrity is gradually destroyed, leading to CO2 leakage. The leaked CO2 will corrode the cement, causing the overall performance of the cement to decrease, and further leading to the formation of annular channeling flow in the cementing of CCUS wells, which not only affects the drilling operation, but also causes the whole well to be scrapped in serious cases.

[0004] At present, two aspects are mainly used to avoid the leakage of carbon dioxide in the cementing of CCUS wells; on the one hand, the strength and toughness of the cement are improved by chemical modification or physical modification, so as to slow down the corrosion of carbon dioxide on the cement and improve the anti-gas channeling capacity of the cement; but this method can only guarantee the integrity of the cement stone in the early stage, and once the microcracks appear in the cement stone in the actual production and use process, it will not be able to effectively seal again. On the other hand, a repairing agent that can respond to the external environment is added to the cement slurry, such as a conventional water-absorbing polymer, but this method will affect the thickening performance and mechanical properties of the cement slurry.

[0005] Therefore, it is an urgent problem in the field to develop a material that can improve the mechanical properties, interfacial adhesion properties and thickening properties of the cement slurry, prevent the corrosion of carbon dioxide on the cement, realize the self-repairing of the microcracks of the cement, and effectively prevent and control the annular channeling flow. SUMMARY

[0006] In view of the deficiencies of the prior art, the present application aims to provide a carbon dioxide self-healing material and a preparation method and application thereof.The carbon dioxide self-healing material has excellent mechanical properties, interfacial adhesion properties and good responsiveness to carbon dioxide; as a self-healing agent, it is used in cement paste, which can not only improve the mechanical properties, interfacial adhesion properties and thickening properties of the cement paste, ensuring the integrity of the cement paste in the early stage, but also prevent the cement paste from being corroded by carbon dioxide and effectively plug microcracks in the later stage, realizing the self-repairing of the cement.

[0007] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0008] In the first aspect, the present application provides a carbon dioxide self-healing material, which comprises a base material and a coating material coated on the surface of the base material; the preparation raw materials of the base material comprise an acrylamide monomer, a first acrylic ester monomer and a first carbon dioxide responsive compound; and the preparation raw materials of the coating material comprise a second acrylic ester monomer and a second carbon dioxide responsive compound.

[0009] In the present application, the base material is compounded by an acrylamide monomer that can produce anions by hydrolysis and a hydrophobic acrylic ester monomer, the mechanical properties of the material are improved by combining hydrophobic association and chemical crosslinking, the strength of the material hydration can be controlled by the balance between hydrophilicity and hydrophobicity, thereby improving the salt expansion resistance and toughness of the cement, and the interfacial adhesion properties of the material are also improved; the first carbon dioxide responsive compound serves as a carbon dioxide sensitive unit and an adhesion unit, has good responsiveness to carbon dioxide, can react with carbon dioxide, thereby helping to realize the self-repairing of the cement; further, the surface of the base material is hydrophobically modified by the coating material, which can delay the hydration time of the base material, regulate the thickening properties of the cement paste, and also improve the adhesion properties between the material and the inorganic interface; at the same time, the coating material also comprises a second carbon dioxide responsive compound, which can also react with carbon dioxide, further improving the self-repairing properties of the cement; the cement paste comprising the carbon dioxide self-healing material has good carbon dioxide corrosion resistance and self-healing ability in the presence of carbon dioxide, and the cement has high strength and good toughness, has good rheological properties, adhesion properties and thickening properties, and can effectively prevent and control the annular channeling.

[0010] Preferably, the mass ratio of the acrylamide-based monomer, the first acrylic ester-based monomer, and the first carbon dioxide-responsive compound is 1 : (0.1-0.6) : (0.3-0.8), wherein the specific value in (0.1-0.6) can be, for example, 0.1, 0.12, 0.14, 0.16, 0.18, 0.2, 0.22, 0.24, 0.26, 0.28, 0.3, 0.32, 0.34, 0.36, 0.38, 0.4, 0.42, 0.44, 0.46, 0.48, 0.5, 0.52, 0.54, 0.56, 0.58, 0.6, etc., and the specific value in (0.3-0.8) can be, for example, 0.3, 0.32, 0.34, 0.36, 0.38, 0.4, 0.42, 0.44, 0.46, 0.48, 0.5, 0.52, 0.54, 0.56, 0.58, 0.6, 0.62, 0.65, 0.68, 0.7, 0.72, 0.75, 0.78, 0.8, etc.

[0011] Preferably, the acrylamide-based monomer includes acrylamide and / or methacrylamide.

[0012] Preferably, the first acrylic ester-based monomer includes a C1-C18 alkyl (meth)acrylate, wherein C1-C18 can be, for example, C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C12, C14, C16, C18, etc., and preferably a C4-C12 alkyl (meth)acrylate.

[0013] Preferably, the first acrylic ester-based monomer includes at least one of methyl methacrylate, butyl acrylate, isooctyl acrylate, lauryl methacrylate, lauryl acrylate, stearyl acrylate, or stearyl methacrylate.

[0014] Preferably, the first carbon dioxide-responsive compound includes a compound containing an amino group and a carbon-carbon double bond.

[0015] Preferably, the first carbon dioxide-responsive compound includes at least one of methacryloyloxyethyl trimethyl ammonium chloride, acryloyloxyethyl trimethyl ammonium chloride, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, dipropylaminoethyl methacrylate.

[0016] Preferably, the raw material for preparing the base material further includes an initiator and a surfactant.

[0017] Preferably, the mass of the initiator and the mass of the surfactant are each independently 0.05-5% based on 100% of the total mass of the acrylamide-based monomer, the first acrylic ester-based monomer, and the first carbon dioxide-responsive compound, for example, 0.05%, 0.1%, 0.2%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 3.8%, 4%, 4.2%, 4.5%, 4.8%, 5%, and the like.

[0018] In the present application, the initiator includes, but is not limited to, at least one of ammonium persulfate, potassium persulfate, azobisisobutyronitrile, and benzoyl peroxide; and the surfactant includes sodium dodecyl sulfate and / or cetyltrimethylammonium chloride, preferably sodium dodecyl sulfate and cetyltrimethylammonium chloride.

[0019] Preferably, the mass ratio of the second acrylic ester-based monomer to the second carbon dioxide-responsive compound is 1:(0.45-0.85), wherein the specific value in (0.45-0.85) can be, for example, 0.45, 0.46, 0.48, 0.5, 0.52, 0.54, 0.56, 0.58, 0.6, 0.62, 0.64, 0.66, 0.68, 0.7, 0.72, 0.74, 0.76, 0.78, 0.8, 0.82, 0.84, 0.85, and the like.

[0020] Preferably, the second acrylic ester-based monomer includes C1-C8 alkyl (meth)acrylate, wherein C1-C8 can be, for example, C1, C2, C3, C4, C5, C6, C7, C8, and the like, and exemplarily, the C1-C8 alkyl (meth)acrylate includes methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isooctyl (meth)acrylate, and the like.

[0021] Preferably, the second acrylic ester-based monomer includes methyl methacrylate and butyl methacrylate.

[0022] Preferably, the mass ratio of the methyl methacrylate to the butyl methacrylate is 1:(1.5-2.5), wherein the specific value in (1.5-2.5) can be, for example, 1.5, 1.52, 1.55, 1.58, 1.6, 1.62, 1.65, 1.68, 1.7, 1.72, 1.75, 1.78, 1.8, 1.82, 1.85, 1.88, 1.9, 1.92, 1.95, 1.98, 2, 2.1, 2.2, 2.3, 2.4, 2.5, and the like.

[0023] Preferably, the second carbon dioxide responsive compound comprises at least one of methacryloyloxyethyl trimethyl ammonium chloride, acryloyloxyethyl trimethyl ammonium chloride, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, dipropylaminoethyl methacrylate.

[0024] Preferably, the preparation raw material of the coating material further comprises a cellulose compound.

[0025] Preferably, the mass ratio of the second carbon dioxide responsive compound and the cellulose compound is 1:(0.2-0.6), wherein the specific value in (0.2-0.6) can be 0.2, 0.22, 0.24, 0.26, 0.28, 0.3, 0.32, 0.34, 0.36, 0.38, 0.4, 0.42, 0.44, 0.46, 0.48, 0.5, 0.52, 0.54, 0.56, 0.58, 0.6, etc.

[0026] Preferably, the cellulose compound comprises at least one of ethyl cellulose, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, or cellulose acetate.

[0027] Preferably, the preparation raw material of the coating material further comprises an initiator and / or an emulsifier.

[0028] Preferably, the mass of the initiator and the emulsifier is independently 0.05-5% based on the total mass of the second acrylate monomer and the second carbon dioxide responsive compound, for example, 0.05%, 0.1%, 0.2%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 3.8%, 4%, 4.2%, 4.5%, 4.8%, 5%, etc.

[0029] In the present application, the initiator in the coating material comprises at least one of ammonium persulfate, potassium persulfate, or sodium persulfate; and the emulsifier comprises at least one of sodium dodecyl benzene sulfonate, nonylphenol polyoxyethylene ether, glyceryl stearate, Tween 20, Tween 40, or Tween 60.

[0030] Preferably, the ratio of the base material to the additive amount of the coating material is 1:(0.4-1.8), wherein the specific value in (0.4-1.8) can be, for example, 0.4, 0.42, 0.44, 0.46, 0.48, 0.5, 0.52, 0.55, 0.58, 0.6, 0.62, 0.65, 0.68, 0.7, 0.72, 0.75, 0.78, 0.8, 0.82, 0.85, 0.88, 0.9, 0.92, 0.95, 0.98, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, etc.

[0031] In a second aspect, the present application provides a preparation method of the carbon dioxide self-healing material according to the first aspect, the preparation method comprising:

[0032] coating the base material with the coating material to obtain the carbon dioxide self-healing material.

[0033] Preferably, the coating method comprises a spray drying coating method.

[0034] Preferably, the coating device comprises a fluidized bed.

[0035] Preferably, the gas flow rate of the coating is 5-10 m 3 / min, which can be, for example, 5 m 3 / min, 6 m 3 / min, 7 m 3 / min, 8 m 3 / min, 9 m 3 / min, 10 m 3 / min, etc.; the atomization pressure is 1-20 bar, which can be, for example, 1 bar, 2 bar, 4 bar, 6 bar, 8 bar, 10 bar, 12 bar, 14 bar, 16 bar, 18 bar, 20 bar, etc.; the liquid spraying amount is 20-60 g / min, which can be, for example, 20 g / min, 25 g / min, 30 g / min, 35 g / min, 40 g / min, 45 g / min, 50 g / min, 55 g / min, 60 g / min, etc.; and the drying temperature is 20-80℃, which can be, for example, 20℃, 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, etc.

[0036] Preferably, the preparation method of the base material comprises:

[0037] mixing the first acrylate monomer, the acrylamide monomer, and the first carbon dioxide responsive compound, and reacting to obtain the base material.

[0038] Preferably, the mixing comprises: pre-mixing the first acrylate monomer with a surfactant and a solvent to obtain polymerizable micelles; mixing the polymerizable micelles with the acrylamide monomer and the first carbon dioxide responsive compound; and the solvent comprises water.

[0039] Preferably, the pre-mixing is performed at room temperature for 1-12 hours, for example, 1 hour, 2 hours, 4 hours, 6 hours, 8 hours, 10 hours, 12 hours, etc.

[0040] Preferably, the reaction is performed in the presence of an initiator and a catalyst; the catalyst includes but is not limited to tetramethyl ethylenediamine (TEMED).

[0041] In the present application, the volume of the catalyst is 30-2000 μL, for example, 30 μL, 50 μL, 100 μL, 200 μL, 400 μL, 600 μL, 800 μL, 1000 μL, 1500 μL, 2000 μL, etc., based on 1 g of ammonium persulfate.

[0042] Preferably, the reaction is performed at a temperature of 30-60°C, for example, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, etc.; and the reaction is performed for a time of 4-24 hours, for example, 4 hours, 6 hours, 8 hours, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours, 24 hours, etc.

[0043] In the present application, the material obtained by the reaction is a gel material, which needs to be dried and crushed into granules before coating.

[0044] Preferably, the preparation method of the coating material comprises:

[0045] reacting the second acrylate monomer and the second carbon dioxide responsive compound to obtain the coating material.

[0046] Preferably, the raw material of the reaction further comprises a cellulose compound.

[0047] Preferably, the preparation method of the coating material comprises:

[0048] (1) pre-reacting the second acrylate monomer and the second carbon dioxide responsive compound to obtain an acrylate polymer;

[0049] (2) reacting the acrylate polymer obtained in step (1) with a cellulose compound to obtain the coating material.

[0050] Preferably, the pre-reaction in step (1) further comprises an initiator, an emulsifier and a solvent; and the solvent comprises water.

[0051] Preferably, the temperature of the pre-reaction in step (1) is 40-60℃, for example, it can be 40℃, 45℃, 50℃, 55℃, 60℃, etc.; the time is 2-5h, for example, it can be 2h, 3h, 4h, 5h, etc.

[0052] Preferably, the temperature of the reaction in step (2) is 60-80℃, for example, it can be 60℃, 65℃, 70℃, 75℃, 80℃, etc.; the time is 1-10h, for example, it can be 1h, 2h, 4h, 6h, 8h, 10h, etc.

[0053] In a third aspect, the present application provides a self-healing toughness anti-channeling cement slurry, which comprises the carbon dioxide self-healing material according to the first aspect.

[0054] In the present application, the self-healing toughness anti-channeling cement slurry comprises cement, water, the carbon dioxide self-healing material, and other additives; the other additives comprise at least one of a toughening agent, an anti-corrosion agent, an anti-gas channeling agent, a fluid loss additive, and a dispersing agent.

[0055] In the present application, the mass ratio of cement to water in the self-healing toughness anti-channeling cement slurry is 100:40-60; the mass of the carbon dioxide self-healing material is 2-15% of the mass of the cement, for example, it can be 2%, 4%, 6%, 8%, 10%, 12%, 14%, 15%, etc.; the mass of the other additives is 0-35% of the mass of the cement, for example, it can be 0%, 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 35%, etc.

[0056] The numerical range in the present application not only includes the point values listed above, but also includes any point values between the above numerical ranges that are not listed, and the present application does not list the specific point values included in the range for the sake of brevity and simplicity.

[0057] Compared with the prior art, the present application has the following beneficial effects:

[0058] The carbon dioxide self-healing material provided by this invention, by setting a coating material on the surface of a matrix material, and by selecting monomer raw materials with specific compositions for both the matrix material and the coating material, gives the carbon dioxide self-healing material excellent mechanical properties, interfacial adhesion properties, and good responsiveness to carbon dioxide. It not only improves the mechanical properties, interfacial adhesion properties, and thickening properties of cement slurry, ensuring the integrity of the cement slurry in the early stages, but also prevents the cement slurry from being corroded by carbon dioxide. When microcracks appear later, it can also effectively seal them, achieving self-repair of the cement. The cement slurry containing the carbon dioxide self-healing material exhibits a flow reduction rate of ≥21% after 1 day of curing, and a flow reduction rate of ≥54% after 7 days of curing; a permeability increase rate of ≤18.4%; a compressive strength of ≥22.6 MPa, and an elastic modulus of ≤6.7 GPa; T 100Bc ≥141 min; the adhesion force of the carbon dioxide self-healing material is ≥1.5 MPa. Detailed Implementation

[0059] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0060] Example 1

[0061] This embodiment provides a carbon dioxide self-healing material, comprising a matrix material and a coating material coated on the surface of the matrix material; the mass ratio of the matrix material to the coating material is 1:1.5; the raw materials for preparing the matrix material include acrylamide, n-butyl acrylate, and dimethylaminoethyl methacrylate in a mass ratio of 1:0.4:0.5; the coating material includes a second acrylate monomer and methacryloyloxyethyltrimethylammonium chloride in a mass ratio of 1:0.6; the second acrylate monomer includes methyl methacrylate and butyl methacrylate in a mass ratio of 1:2; the coating material further includes hydroxyethyl cellulose, and the mass ratio of methacryloyloxyethyltrimethylammonium chloride to hydroxyethyl cellulose is 1:0.4.

[0062] This embodiment provides a method for preparing a carbon dioxide self-healing material, specifically including the following steps:

[0063] (1) Preparation of matrix material

[0064] Sodium dodecyl sulfate, cetyltrimethylammonium chloride and water were mixed to prepare a micellar solution with a concentration of 5 mg / mL (the mass ratio of sodium dodecyl sulfate to cetyltrimethylammonium chloride was 1:1, and the total mass of sodium dodecyl sulfate and cetyltrimethylammonium chloride was 3% of the total mass of acrylamide, n-butyl acrylate and dimethylaminoethyl methacrylate), n-butyl acrylate was added thereto, and stirring was performed at room temperature for 4 h to obtain a polymerizable micellar solution; the polymerizable micellar solution was mixed with acrylamide and dimethylaminoethyl methacrylate, ammonium persulfate (1% of the total mass of acrylamide, n-butyl acrylate and dimethylaminoethyl methacrylate) and TEMED (100 μL of TEMED was added for 1 g of ammonium persulfate) were added thereto, and reaction was performed at 30°C for 12 h to obtain a gel material, which was dried and crushed into particles to obtain the matrix material.

[0065] (2) Preparation of the coating material

[0066] Methyl methacrylate, butyl methacrylate, methacryloyloxyethyl trimethylammonium chloride, sodium dodecylbenzenesulfonate (0.5% of the total mass of methyl methacrylate, butyl methacrylate and methacryloyloxyethyl trimethylammonium chloride) and water (4 times of the total mass of methyl methacrylate, butyl methacrylate, methacryloyloxyethyl trimethylammonium chloride and sodium dodecylbenzenesulfonate) were mixed, and the temperature was raised to 40°C; an aqueous solution of potassium persulfate (50% by mass, 1.5% of the total mass of methyl methacrylate, butyl methacrylate and methacryloyloxyethyl trimethylammonium chloride) was added dropwise thereto under stirring, the dropwise addition was performed for 1 h, and after the dropwise addition was completed, reaction was continued for 5 h; then, hydroxyethyl cellulose was added, and reaction was performed at 70°C for 6 h, and the temperature was cooled to room temperature to obtain the coating material.

[0067] (3) Preparation of the carbon dioxide self-healing material

[0068] According to the formulation amount, the matrix material was placed in a fluidized bed by using a spray drying coating method, the coating material was sprayed on the surface of the matrix material, and drying was simultaneously performed; wherein the process parameters of the coating were as follows: the air flow rate was 8 m / min, the atomization pressure was 8 bar, the spraying liquid amount was 30 g / min, and the drying temperature was 60°C; and the carbon dioxide self-healing material was obtained. 3

[0069] Example 2

[0070] ​The embodiment provides a carbon dioxide self-healing material, which comprises a base material and a coating material coated on the surface of the base material; the adding mass ratio of the base material to the coating material is 1:0.5; the base material is prepared from raw materials in a mass ratio of acrylamide, lauryl methacrylate and acryloyloxyethyl trimethyl ammonium chloride, which is 1:0.2:0.75; the coating material comprises a second acrylic monomer and dipropylaminoethyl methacrylate in a mass ratio of 1:0.5; the second acrylic monomer comprises methyl methacrylate and butyl methacrylate in a mass ratio of 1:1.6; and the coating material further comprises hydroxypropyl methyl cellulose, and the mass ratio of the dipropylaminoethyl methacrylate to the hydroxypropyl methyl cellulose is 1:0.6.

[0071] The embodiment provides a preparation method of the carbon dioxide self-healing material.

[0072] Embodiment 3

[0073] The embodiment provides a carbon dioxide self-healing material, which comprises a base material and a coating material coated on the surface of the base material; the adding mass ratio of the base material to the coating material is 1:1.2; the base material is prepared from raw materials in a mass ratio of acrylamide, butyl acrylate and dipropylaminoethyl methacrylate, which is 1:0.6:0.35; the coating material comprises a second acrylic monomer and dipropylaminoethyl methacrylate in a mass ratio of 1:0.8; the second acrylic monomer comprises methyl methacrylate and butyl methacrylate in a mass ratio of 1:2.2; and the coating material further comprises hydroxypropyl methyl cellulose, and the mass ratio of the dipropylaminoethyl methacrylate to the hydroxypropyl methyl cellulose is 1:0.2.

[0074] The embodiment provides a preparation method of the carbon dioxide self-healing material.

[0075] Embodiment 4

[0076] The embodiment provides a carbon dioxide self-healing material, which is different from the embodiment 1 only in that the amount of the coating material is increased, so that the mass ratio of the base material to the coating material is 1:2.2, and the other raw materials, the amount and the preparation method are the same as those of the embodiment 1.

[0077] Embodiment 5

[0078] The embodiment provides a carbon dioxide self-healing material, which is different from the embodiment 1 only in that the amount of the coating material is reduced, so that the mass ratio of the base material to the coating material is 1:0.1, and the other raw materials, the amount and the preparation method are the same as those of the embodiment 1.

[0079] Embodiment 6

[0080] The embodiment 7 provides a carbon dioxide self-healing material, which is different from the embodiment 1 only in that the total mass of acrylamide, n-butyl acrylate and dimethylaminoethyl methacrylate in the base material is unchanged, the mass ratio is 1:1:0.1, and other raw materials, dosages and preparation methods are the same as those of the embodiment 1.

[0081] Embodiment 7

[0082] The embodiment 7 provides a carbon dioxide self-healing material, which is different from the embodiment 1 only in that the total mass of acrylamide, n-butyl acrylate and dimethylaminoethyl methacrylate in the base material is unchanged, the mass ratio is 1:1:0.1, and other raw materials, dosages and preparation methods are the same as those of the embodiment 1.

[0083] Embodiment 8

[0084] The embodiment 7 provides a carbon dioxide self-healing material, which is different from the embodiment 1 only in that the total mass of acrylamide, n-butyl acrylate and dimethylaminoethyl methacrylate in the base material is unchanged, the mass ratio is 1:1:0.1, and other raw materials, dosages and preparation methods are the same as those of the embodiment 1.

[0085] Embodiment 9

[0086] The embodiment 7 provides a carbon dioxide self-healing material, which is different from the embodiment 1 only in that the total mass of acrylamide, n-butyl acrylate and dimethylaminoethyl methacrylate in the base material is unchanged, the mass ratio is 1:1:0.1, and other raw materials, dosages and preparation methods are the same as those of the embodiment 1.

[0087] Embodiment 10

[0088] The embodiment 7 provides a carbon dioxide self-healing material, which is different from the embodiment 1 only in that the total mass of acrylamide, n-butyl acrylate and dimethylaminoethyl methacrylate in the base material is unchanged, the mass ratio is 1:1:0.1, and other raw materials, dosages and preparation methods are the same as those of the embodiment 1.

[0089] Embodiment 11

[0090] The embodiment 7 provides a carbon dioxide self-healing material, which is different from the embodiment 1 only in that the total mass of acrylamide, n-butyl acrylate and dimethylaminoethyl methacrylate in the base material is unchanged, the mass ratio is 1:1:0.1, and other raw materials, dosages and preparation methods are the same as those of the embodiment 1.

[0091] Embodiment 12

[0092] The embodiment provides a carbon dioxide self-healing material, which is only different from the embodiment 1 in that the amount of hydroxyethyl cellulose is increased in the coating material, so that the mass ratio of methacryloxyethyl trimethyl ammonium chloride and hydroxyethyl cellulose is 1:1, and other raw materials, amounts and preparation methods are the same as those of the embodiment 1.

[0093] Embodiment 13

[0094] The embodiment provides a carbon dioxide self-healing material, which is only different from the embodiment 1 in that the amount of hydroxyethyl cellulose is increased in the coating material, so that the mass ratio of methacryloxyethyl trimethyl ammonium chloride and hydroxyethyl cellulose is 1:1, and other raw materials, amounts and preparation methods are the same as those of the embodiment 1.

[0095] Comparative Example 1

[0096] The comparative example provides a carbon dioxide self-healing material, which is the matrix material provided in the embodiment 1.

[0097] Comparative Example 2

[0098] The comparative example provides a carbon dioxide self-healing material, which is the coating material provided in the embodiment 1.

[0099] Comparative Example 3

[0100] The comparative example provides a carbon dioxide self-healing material, which is only different from the embodiment 1 in that the coating material is hydroxyethyl cellulose, and other raw materials, amounts and preparation methods are the same as those of the embodiment 1.

[0101] Application Example

[0102] A self-healing and toughening anti-channeling cement slurry, which comprises 100 parts of G-grade cement, 60 parts of water, 10 parts of a self-healing agent, 20 parts of an anti-corrosion agent (GWB-200S), 5 parts of a toughening agent (GWI-200S), 5 parts of an anti-gas-channeling agent (GWT-200S), 3 parts of a fluid loss additive (GWF-200S) and 1.5 parts of a dispersing agent (GWD-1S) in terms of weight parts; the self-healing agent is the carbon dioxide self-healing material provided in the embodiments 1 to 13 and the comparative examples 1 to 3; and other additives are all produced by the Cementing Company of China Petroleum Group Great Wall Drilling Engineering Co., Ltd.

[0103] Performance Test

[0104] The cement slurry is prepared according to the method specified in Chapter 5 of GB / T 19139-2012, relevant cement slurry experiments are carried out, and the thickening performance, mechanical performance, interfacial adhesion performance, anti-corrosion performance and carbon dioxide self-repairing performance of the self-healing and toughening anti-channeling cement slurry are tested.

[0105] (1) Consistency: test according to GB / T 19139 method, record the initial consistency and consistency time (T 100Bc ) at 80℃;

[0106] (2) Mechanical properties: the cement paste is cured at 80℃ for 48h, and the compressive strength and elastic modulus of the cement paste are tested according to GB / T 19139 (7.5) method;

[0107] (3) Interfacial adhesion properties: two identical cement stone samples are accurately prepared, and the self-healing agent is adhered to the smooth surface of the two cement blocks, and then the surfaces of the two cement blocks adhered with the self-healing agent are fixed in contact with each other, and are placed in a curing oven filled with CO2 gas and cured at a temperature required by the experiment for different ages, and are cooled at room temperature for 45min after being taken out. Finally, the cement blocks adhered together are placed on the clamps of a universal testing machine, the tensile speed of the universal testing machine is set to 5mm / min, and the cement blocks are slowly stretched until they are completely broken, and the maximum tension divided by the bonding area is the shear strength.

[0108] (4) Anti-corrosion properties: the prepared cement paste is poured into a cubic mold (50x50x50mm) and a cylindrical mold (Φ25x25mm) respectively, and is cured at 80℃, 20.7MPa pressure and humid environment for 3 days. After the cement stone is solidified, the sample is taken out from the mold, and the permeability of the sample before and after carbon dioxide corrosion is tested according to GB / T 19139 (11.4) (test temperature 60℃, pressure 30MPa, temperature rising time 30min), and the permeability growth rate after 60 days is calculated according to the following formula; the smaller the permeability growth rate, the better the anti-carbon dioxide corrosion effect;

[0109] τ=(μ1-μ0) / μ1x100%;

[0110] Wherein: τ - permeability growth rate, %; μ0 - permeability before corrosion, mD; μ1 - permeability after 60 days of carbon dioxide corrosion, mD;

[0111] (5) Carbon dioxide self-repairing properties: the prepared cement paste is cured according to the provided test conditions (cyclic temperature 60℃, pressure 30MPa, temperature rising time 30min) using a carbon dioxide healing tester, after curing and molding, the inner cylinder is pressurized, the cement stone in the annular space is fractured to form cracks, dry air or nitrogen is introduced, and the cement stone channeling flow S0 is tested; stop injecting air or nitrogen, and inject carbon dioxide gas for curing, replace the carbon dioxide gas with dry air or nitrogen after a certain period of time, and test the cement stone channeling flow S1. The channeling flow reduction rate θ is calculated according to the following formula;

[0112] θ=(S0-S1) / S0x100%;

[0113] wherein: θ - the channeling flow reduction rate, %;

[0114] S0 - the channeling flow before healing, sccm;

[0115] S1 - the channeling flow after healing for a certain time in the carbon dioxide medium, sccm;

[0116] The channeling flow reduction rates for 1 day and 7 days of curing are recorded, and the greater the channeling flow reduction rate, the better the self-healing performance.

[0117] The specific test results are shown in Table 1.

[0118] Table 1

[0119]

[0120]

[0121] As can be seen from Table 1, the carbon dioxide self-healing material provided by the present application has good mechanical properties, interfacial adhesion properties and thickening properties by arranging the coating material on the surface of the base material and selecting the monomer raw material with a specific composition for the base material and the coating material; the carbon dioxide self-healing material has strong carbon dioxide corrosion resistance and strong carbon dioxide self-healing ability, and can effectively prevent and control annular channeling; the cement slurry comprising the carbon dioxide self-healing material has a channeling flow reduction rate of 21-51% after 1 day of curing and a channeling flow reduction rate of 54-95% after 7 days of curing; the permeability growth rate is 7.6-18.4%; the compressive strength is 22.6-29.4 MPa, and the elastic modulus is 5.1-6.7 GPa; T 100Bc The adhesion of the carbon dioxide self-healing material is 1.5-4.3 MPa.

[0122] As can be seen from Comparative Examples 1-3, the thickening properties, mechanical properties, carbon dioxide corrosion resistance and carbon dioxide self-repairing properties of the cement slurry are significantly deteriorated when the carbon dioxide self-healing material with the specific structure of the present application is not used.

[0123] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application, and it should be understood that the above description is only for specific embodiments of the present application and is not intended to limit the present application, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A carbon dioxide self-healing material, characterized by, The carbon dioxide self-healing material comprises a base material and a coating material coated on the surface of the base material; The preparation raw material of the base material comprises an acrylamide monomer, a first acrylic ester monomer, and a first carbon dioxide responsive compound; The preparation raw material of the coating material comprises a second acrylic ester monomer and a second carbon dioxide responsive compound.

2. The carbon dioxide self-healing material of claim 1, wherein, The mass ratio of the acrylamide monomer, the first acrylic ester monomer, and the first carbon dioxide responsive compound is 1:(0.1-0.6):(0.3-0.8).

3. The carbon dioxide self-healing material according to claim 1 or 2, characterized in that, The acrylamide monomer comprises acrylamide and / or methacrylamide; Preferably, the first acrylic ester monomer comprises C1-C18 alkyl (meth)acrylate; Preferably, the first acrylic ester monomer comprises at least one of methyl methacrylate, butyl acrylate, isooctyl acrylate, lauryl methacrylate, lauryl acrylate, stearyl acrylate, and stearyl methacrylate; Preferably, the first carbon dioxide responsive compound comprises a compound containing an amino group and a carbon-carbon double bond; Preferably, the first carbon dioxide responsive compound comprises at least one of methacryloyloxyethyl trimethyl ammonium chloride, acryloyloxyethyl trimethyl ammonium chloride, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and dipropylaminoethyl methacrylate; Preferably, the preparation raw material of the base material further comprises an initiator and a surfactant; Preferably, the mass of the initiator and the surfactant is independently 0.05-5% based on 100% of the total mass of the acrylamide monomer, the first acrylic ester monomer, and the first carbon dioxide responsive compound.

4. The carbon dioxide self-healing material according to any one of claims 1 to 3, characterized in that, The mass ratio of the second acrylic ester monomer and the second carbon dioxide responsive compound is 1:(0.45-0.85); Preferably, the second acrylic ester monomer comprises C1-C8 alkyl (meth)acrylate; Preferably, the second acrylic ester monomer comprises methyl methacrylate and butyl methacrylate; Preferably, the mass ratio of the methyl methacrylate and the butyl methacrylate is 1:(1.5-2.5); Preferably, the second carbon dioxide responsive compound comprises at least one of methacryloyloxyethyl trimethyl ammonium chloride, acryloyloxyethyl trimethyl ammonium chloride, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and dipropylaminoethyl methacrylate; Preferably, the preparation raw material of the coating material further comprises a cellulose compound; Preferably, the mass ratio of the second carbon dioxide responsive compound and the cellulose compound is 1:(0.2-0.6); Preferably, the cellulose compound comprises at least one of ethyl cellulose, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, and cellulose acetate; Preferably, the preparation raw material of the coating material further comprises an initiator and / or an emulsifier; Preferably, the mass of the initiator and the emulsifier is independently 0.05-5% based on 100% of the total mass of the second acrylic ester monomer and the second carbon dioxide responsive compound.

5. The carbon dioxide self-healing material according to any one of claims 1 to 4, characterized in that, The ratio of the base material to the additive amount of the coating material is 1:(0.4-1.8).

6. A method for producing the carbon dioxide self-healing material according to any one of claims 1 to 5, characterized by, The preparation method comprises: Coating the coating material on the surface of the base material to obtain the carbon dioxide self-healing material.

7. The preparation method according to claim 6, characterized in that, The coating method comprises a spray drying coating method; Preferably, the coating device comprises a fluidized bed; Preferably, the coated air flow rate is 5-10 m 3 / min, the atomization pressure is 1-20 bar, the liquid spray amount is 20-60 g / min, and the drying temperature is 20-80°C.

8. The production method according to claim 6 or 7, characterized by, The preparation method of the base material comprises: Mixing, reacting a first acrylate monomer, an acrylamide monomer and a first carbon dioxide responsive compound to obtain the base material; Preferably, the mixing comprises: pre-mixing the first acrylate monomer with a surfactant and a solvent to obtain polymerizable micelles; mixing the polymerizable micelles with the acrylamide monomer and the first carbon dioxide responsive compound; Preferably, the pre-mixing is carried out at room temperature for 1-12 hours; Preferably, the reaction is carried out in the presence of an initiator and a catalyst; Preferably, the reaction is carried out at a temperature of 30-60℃ for 4-24 hours.

9. The method of any one of claims 6 to 8, wherein the method further comprises, The preparation method of the coating material comprises: Reacting a second acrylate monomer and a second carbon dioxide responsive compound to obtain the coating material; Preferably, the raw material of the reaction further comprises a cellulose compound; Preferably, the preparation method of the coating material comprises: (1) pre-reacting a second acrylate monomer and a second carbon dioxide responsive compound to obtain an acrylate polymer; (2) reacting the acrylate polymer obtained in step (1) with a cellulose compound to obtain the coating material; Preferably, the raw material of the pre-reaction in step (1) further comprises an initiator, an emulsifier and a solvent; Preferably, the pre-reaction in step (1) is carried out at a temperature of 40-60℃ for 2-5 hours; Preferably, the reaction in step (2) is carried out at a temperature of 60-80℃ for 1-10 hours.

10. A self-healing tenacious anti-channeling cement paste, characterized in that, The self-healing ductile anti-channeling cement slurry comprises the carbon dioxide self-healing material according to any one of claims 1-5.

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