Plugging agent as well as preparation method and application thereof

Abstract

The invention discloses a plugging agent as well as a preparation method and application thereof, and belongs to the technical field of oil and gas drilling engineering. The invention discloses a plugging agent. Comprising the following components in parts by weight: 22 to 32 parts of water-based organic silicon modified high-temperature-resistant resin emulsion, 1.8 to 3.5 parts of caprolactam closed type diphenylmethane diisocyanate, 4 to 9 parts of aminated carbon quantum dot dispersion liquid, 1.8 to 3.5 parts of alkaline silica-alumina sol, 8 to 18 parts of high-temperature-resistant fibrous material, 1.5 to 2.8 parts of sodium dodecyl diphenyl ether disulfonate and 1.5 to 2.8 parts of polyethylene glycol-polypropylene glycol segmented copolymer. 0.8 to 1.8 parts of sodium citrate and 0.8 to 1.8 parts of sulfonated polysulfone. The invention also provides a preparation method of the plugging agent and application of the plugging agent in drilling fractured leakage. The plugging agent still has high plugging strength at high temperature.

Description

Technical Field

[0001] This invention relates to the field of oil and gas drilling engineering technology, specifically to a plugging agent, its preparation method, and its application. Background Technology

[0002] As exploration and development of ultra-deep oilfields such as Fuman in Tarim Basin and Anyue in Sichuan Province, as well as ultra-deep and ultra-high temperature blocks in the Bohai Bay area with burial depths exceeding 8,000 meters and formation temperatures exceeding 220°C, continue to deepen, unprecedented challenges are posed to the long-term temperature resistance (220-250°C), deep retention capacity, and final sealing strength of plugging materials.

[0003] Patent CN202410723257.3 discloses a self-consolidating plugging agent, which is made by pre-coating a temperature-curing phenolic resin onto the surface of a quartz sand skeleton, high-temperature resistant fibers, and conventional plugging particles, and then compounding it with toughening resin powder. This plugging agent aims to physically bridge the leaking layer after entering it, and then rely on the thermosetting reaction of the resin to bind the dispersed materials into a monolithic structure, thereby improving its compressive strength and retention. The consolidated body can achieve a compressive strength of over 8 MPa at 200℃. However, the above-mentioned plugging material is essentially a pre-coated chemically consolidated plugging agent. Its temperature resistance evaluation is concentrated at 200℃, and its long-term reliability is insufficient at extreme high temperatures of 220-250℃. Furthermore, its solid powder form faces challenges in compatibility with complex drilling fluid systems and its transport performance in deep fractures. Simultaneously, its curing process relies on temperature rise and lacks a precise delayed triggering mechanism, limiting its application safety and precise sealing of deep, targeted leaking layers.

[0004] Patent CN201610405315.3 discloses a high-strength, ductile sealant, which is formed by high-temperature melting and compounding aluminum or aluminum alloy powder as the main bridging component with inorganic materials such as expandable graphite and silicon carbide. This sealant aims to penetrate the leaking layer, using the aluminum-based material to achieve physical bridging, and relying on the overall strength and ductility of the composite material to seal cracks, thereby improving pressure resistance and erosion resistance. Its sealant body can achieve a compressive strength of over 23 MPa at 160°C. However, the aforementioned sealing materials are essentially high-temperature sintering physical bridging sealants, and their temperature resistance evaluation is concentrated at 160℃. At extreme high temperatures of 220-250℃, the strength retention rate and long-term thermal stability of aluminum-based materials face challenges. Moreover, their sealing mechanism relies on rigid particles of a preset particle size for bridging, which limits their adaptive filling ability for complex crack morphologies. In addition, their preparation process requires high-temperature melting at 600-800℃, which is complex and energy-intensive. Furthermore, the finished product is made of rigid particles, which may have insufficient transport and retention properties in deep dynamic cracks.

[0005] Based on the above analysis, the problem of fracture-induced leakage during drilling in ultra-deep and ultra-high temperature blocks places higher demands on the high-temperature resistance, deep retention, and sealing strength of plugging materials. There is an urgent need to develop a new plugging system that combines physical bridging ability with controllable chemical consolidation characteristics to cope with such complex working conditions. Summary of the Invention

[0006] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide a sealing agent, its preparation method and application, thereby solving the technical problem of how to achieve high sealing strength at high temperatures in the prior art.

[0007] To achieve the above-mentioned technical objectives, the present invention provides a sealing agent, comprising, by weight parts: 22-32 parts of water-based organosilicon-modified high-temperature resistant resin emulsion, 1.8-3.5 parts of caprolactam-blocked diphenylmethane diisocyanate, 4-9 parts of aminated carbon quantum dot dispersion, 1.8-3.5 parts of alkaline silica-alumina sol, 8-18 parts of high-temperature resistant fibrous material, 1.5-2.8 parts of sodium dodecyl diphenyl ether disulfonate, 1.5-2.8 parts of polyethylene glycol-polypropylene glycol block copolymer, 0.8-1.8 parts of sodium citrate, 0.8-1.8 parts of sulfonated polysulfone, 1.2-2.8 parts of shale inhibitor, 0.2-0.4 parts of isothiazolinone derivative, 0.15-0.4 parts of defoamer, and 58-68 parts of water.

[0008] In any embodiment, the composition, by weight, includes: 25-30 parts of waterborne silicone-modified high-temperature resistant resin emulsion, 2.0-3.0 parts of caprolactam-blocked diphenylmethane diisocyanate, 6-8 parts of aminated carbon quantum dot dispersion, 2.0-3.0 parts of alkaline silica-alumina sol, 10-15 parts of high-temperature resistant fibrous material, 2.0-2.5 parts of sodium dodecyl diphenyl ether disulfonate, 2.0-2.5 parts of polyethylene glycol-polypropylene glycol block copolymer, 1.0-1.5 parts of sodium citrate, 1.0-1.5 parts of sulfonated polysulfone, 1.5-2.5 parts of shale inhibitor, 0.25-0.35 parts of isothiazolinone derivative, 0.2-0.3 parts of defoamer, and 58-68 parts of water.

[0009] In any embodiment, the sealing agent, by weight, comprises: 28 parts of water-based silicone-modified high-temperature resistant resin emulsion, 2.5 parts of caprolactam-blocked diphenylmethane diisocyanate, 7 parts of aminated carbon quantum dot dispersion, 2.5 parts of alkaline silica-alumina sol, 12 parts of high-temperature resistant fibrous material, 2.2 parts of sodium dodecyl diphenyl ether disulfonate, 2.2 parts of polyethylene glycol-polypropylene glycol block copolymer, 1.2 parts of sodium citrate, 1.2 parts of sulfonated polysulfone, 2.0 parts of shale inhibitor, 0.3 parts of isothiazolinone derivative, 0.2 parts of polyether-modified silicone defoamer, and 64.47 parts of water.

[0010] In any embodiment, the high-temperature resistant fibrous material is one or both of aramid fiber and glass fiber.

[0011] In any embodiment, the high-temperature resistant fibrous material has a length of 2-5 mm and a diameter of 15-40 μm.

[0012] In any embodiment, the shale inhibitor is one or more of polyetheramine, polyamine, or polyethyleneamine.

[0013] In any embodiment, the defoamer is a polyether-modified silicone defoamer.

[0014] Furthermore, the present invention also proposes a method for preparing the above-mentioned sealing agent, comprising the following steps: S1. Preparation of the precursor solution: Heat the prescribed amount of water to 40-50℃, and add sodium dodecyl diphenyl ether disulfonate, polyethylene glycol-polypropylene glycol block copolymer, sodium citrate, sulfonated polysulfone, and isothiazolinone derivative in sequence while stirring until completely dissolved; then add aminated carbon quantum dot dispersion and alkaline silica-alumina sol and continue stirring to form an aqueous dispersion; transfer the obtained aqueous dispersion to an emulsification device, add waterborne organosilicon-modified high-temperature resistant resin emulsion while stirring, and then shear emulsify to form an emulsion base liquid; then add shale inhibitor and defoamer in sequence while stirring to obtain the precursor solution; S2. Composite preparation of sealing agent: The precursor liquid obtained in step S1 is transferred to a mixing tank. Under stirring, the formulated amount of high-temperature resistant fibrous material is added to the precursor liquid and stirred to obtain the sealing agent.

[0015] In any embodiment, in step S1, the aqueous dispersion is formed by continuous stirring for 15-20 min; and / or, in step S1, the emulsion is formed by shear emulsification for 10-15 min.

[0016] Furthermore, the present invention also proposes the application of the above-mentioned plugging agent or the plugging agent prepared by the above-mentioned preparation method in drilling fracture leakage.

[0017] In any embodiment, the above application includes: adding the plugging agent at 5%-12% of the total volume of the drilling fluid and pumping it into the target lost circulation zone downhole through the drilling fluid circulation system.

[0018] Compared with the prior art, the beneficial effects of the present invention include: the sealant proposed in the present invention uses caprolactam-blocked isocyanate as a thermal trigger switch, so that the curing reaction is strictly controlled by temperature. By controlling the unsealing temperature and delay time through molecular design, the plugging agent remains stable and pumpable in the low-temperature section of the wellbore, only initiating solidification after entering the target high-temperature leak layer at 220-250℃. This achieves "precise delay and targeted sealing," completely avoiding the downhole construction risks caused by the uncontrollable solidification of chemically solidified materials. The thermally triggered sealing crosslinking agent acts as a "timed switch," ensuring the system is injected at low viscosity and activating the reaction after a delay once it reaches the target temperature in the deep formation. Subsequently, ammoniated carbon quantum dots act as a "nano-skeleton," serving as nucleation centers to guide resin crosslinking and generate uniform particles, while also significantly improving the mechanical strength and compaction resistance of the particles, forming a stable plug. Simultaneously, the combination of nano-carbon quantum dots and alkaline silica-alumina sol optimizes the reaction path and enhances the structural stability of the product under high-temperature and high-salt conditions. Finally, the addition of high-temperature resistant fiber materials further improves the product strength, ensuring the performance stability of the entire system under long-term high-temperature aging. Thus, the synergy of each component ensures the performance stability of the entire system under long-term high-temperature aging. This overcomes the fundamental defects of traditional polymer gel plugging agents, which are prone to degradation and failure at target temperatures. The plugging agent proposed in this invention features a "reinforced concrete-like" integrated structure in which fibers and resin are tightly bonded through physical interlocking and chemical action. This structure has excellent toughness, erosion resistance, and adaptability to crack morphology, effectively resisting the impact of formation fluids and preventing re-leakage. It achieves a performance leap from "temporary sealing" to "permanent sealing," and maintains high sealing strength even at high temperatures.

[0019] The plugging agent proposed in this invention can achieve liquid migration followed by solid curing. Its slurry form ensures excellent pumpability and deep migration capability, while the "fiber-reinforced composite material" structure formed after curing provides pressure resistance far exceeding that of traditional bridging plugging agents. This solves the problem that traditional high-strength resin materials are difficult to inject into deep cracks due to excessive initial viscosity, and achieves high sealing strength at high temperatures. Attached Figure Description

[0020] Figure 1 This is a photograph of the actual plugging particles after the plugging agent in Embodiment 1 of the present invention has been dried. Detailed Implementation

[0021] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60~120 and 80~110 are listed for a specific parameter, it is also expected that ranges of 60~110 and 80~120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1~3, 1~4, 1~5, 2~3, 2~4, and 2~5. In this application, unless otherwise stated, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0022] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0023] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0024] This specific embodiment provides a sealing agent, which, by weight, comprises: 22-32 parts of water-based organosilicon-modified high-temperature resistant resin emulsion, 1.8-3.5 parts of caprolactam-blocked diphenylmethane diisocyanate, 4-9 parts of aminated carbon quantum dot dispersion, 1.8-3.5 parts of alkaline silica-alumina sol, 8-18 parts of high-temperature resistant fibrous material, 1.5-2.8 parts of sodium dodecyl diphenyl ether disulfonate, 1.5-2.8 parts of polyethylene glycol-polypropylene glycol block copolymer, 0.8-1.8 parts of sodium citrate, 0.8-1.8 parts of sulfonated polysulfone, 1.2-2.8 parts of shale inhibitor, 0.2-0.4 parts of isothiazolinone derivative, 0.15-0.4 parts of defoamer, and 58-68 parts of water.

[0025] In some embodiments, the sealing agent, calculated by weight, comprises: 25-30 parts of water-based silicone-modified high-temperature resistant resin emulsion, 2.0-3.0 parts of caprolactam-blocked diphenylmethane diisocyanate, 6-8 parts of aminated carbon quantum dot dispersion, 2.0-3.0 parts of alkaline silica-alumina sol, 10-15 parts of high-temperature resistant fibrous material, 2.0-2.5 parts of sodium dodecyl diphenyl ether disulfonate, 2.0-2.5 parts of polyethylene glycol-polypropylene glycol block copolymer, 1.0-1.5 parts of sodium citrate, 1.0-1.5 parts of sulfonated polysulfone, 1.5-2.5 parts of shale inhibitor, 0.25-0.35 parts of isothiazolinone derivative, 0.2-0.3 parts of defoamer, and 58-68 parts of water.

[0026] In some embodiments, the sealing agent, by weight, comprises: 28 parts of water-based silicone-modified high-temperature resistant resin emulsion, 2.5 parts of caprolactam-blocked diphenylmethane diisocyanate, 7 parts of aminated carbon quantum dot dispersion, 2.5 parts of alkaline silica-alumina sol, 12 parts of high-temperature resistant fibrous material, 2.2 parts of sodium dodecyl diphenyl ether disulfonate, 2.2 parts of polyethylene glycol-polypropylene glycol block copolymer, 1.2 parts of sodium citrate, 1.2 parts of sulfonated polysulfone, 2.0 parts of shale inhibitor, 0.3 parts of isothiazolinone derivative, 0.2 parts of polyether-modified silicone defoamer, and 64.47 parts of water.

[0027] In some embodiments, the high-temperature resistant fibrous material is one or both of aramid fiber and glass fiber, the length of the high-temperature resistant fibrous material is 2-5 mm, and the diameter is 15-40 μm; the shale inhibitor is one or more of polyetheramine, polyamine, or polyethyleneamine; and the defoamer is a polyether-modified silicone defoamer.

[0028] Furthermore, this specific embodiment also proposes a method for preparing the above-mentioned sealing agent, including the following steps: S1. Preparation of the precursor solution: Heat the prescribed amount of water to 40-50℃, and add sodium dodecyl diphenyl ether disulfonate, polyethylene glycol-polypropylene glycol block copolymer, sodium citrate, sulfonated polysulfone, and isothiazolinone derivative sequentially while stirring until completely dissolved; then add amino-modified carbon quantum dot dispersion and alkaline silica-alumina sol and continue stirring for 15-20 min to form an aqueous dispersion; transfer the obtained aqueous dispersion to an emulsification device, add waterborne organosilicon-modified high-temperature resistant resin emulsion while stirring, and then shear emulsify for 10-15 min to form an emulsion base solution; then add shale inhibitor and defoamer sequentially and continue stirring to obtain the precursor solution; S2. Composite preparation of sealing agent: The precursor liquid obtained in step S1 is transferred to a mixing tank. Under stirring, the formulated amount of high-temperature resistant fibrous material is added to the precursor liquid and stirred to obtain the sealing agent.

[0029] Furthermore, this specific embodiment also proposes the application of the above-mentioned plugging agent or the plugging agent prepared by the above-mentioned preparation method in drilling fracture loss, including: adding the plugging agent at 5%-12% of the total volume of drilling fluid, and pumping it into the target lost circulation zone downhole through the drilling fluid circulation system.

[0030] This invention achieves adaptive plugging in high-temperature formations (220-250℃) through a three-stage synergistic mechanism of "rapid fiber bridging, heat-triggered delayed bonding, and nano-reinforcement": fibers first bridge fractures; temperature triggers the unsealing of the closed crosslinking agent, allowing the resin to cure in situ; nano-components enhance interfacial bonding, ultimately forming a high-strength, highly dense integral plug. This plugging agent exhibits good pumpability, delayed curing, and excellent high-temperature stability, making it suitable for efficient plugging of high-temperature fracture-related losses in ultra-deep wells.

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0032] In this invention, the terms "some embodiments," "this embodiment," and examples are used to describe a subset of all possible embodiments. However, it is understood that "some embodiments" can be the same subset or different subsets of all possible embodiments and can be combined with each other without conflict.

[0033] If the application documents contain similar descriptions such as "first / second", the following explanation shall be added: In the following description, the terms "first / second / third" are used only to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first / second / third" may be interchanged in a specific order or sequence where permitted, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein.

[0034] In this embodiment, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, object A and / or object B can represent three situations: object A exists alone, object A and object B exist simultaneously, and object B exists alone.

[0035] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0036] In the following examples or comparative examples, the solid content of the aminated carbon quantum dot dispersion is 20%, and the particle size of the carbon quantum dots in the dispersion is 3-10 nm; the solid content of the aqueous organosilicon-modified high-temperature resistant resin emulsion is 40%. In the following examples or comparative examples, the aqueous organosilicon-modified high-temperature resistant resin emulsion is model S-8618, the alkaline silica-alumina sol is model GS19C, and other pharmaceuticals are also sourced from commercially available sources.

[0037] Example 1 This embodiment proposes a sealing agent comprising: 25.0g of waterborne silicone-modified high-temperature resistant resin emulsion, 2.0g of caprolactam-blocked diphenylmethane diisocyanate, 5.0g of amino-carbon quantum dot dispersion, 2.0g of alkaline silica-alumina sol, 10g of high-temperature resistant fibrous material, 2.0g of sodium dodecyl diphenyl ether disulfonate, 2.0g of polyethylene glycol-polypropylene glycol block copolymer, 1.0g of sodium citrate, 1.0g of sulfonated polysulfone, 1.5g of shale inhibitor, 0.25g of isothiazolinone derivative, 0.2g of polyether-modified silicone defoamer, and 66.17g of water. The high-temperature resistant fibrous material in this embodiment is glass fiber, and the aramid fiber has a length of 2-5mm and a diameter of 15-40μm. The shale inhibitor is polyethyleneamine, and the defoamer is a polyether-modified silicone defoamer.

[0038] This embodiment also proposes a method for preparing the above-mentioned sealing agent, including the following steps: S1. Take water according to the above dosage, heat it to 45°C and place it in a water bath; add sodium dodecyl diphenyl ether disulfonate, polyethylene glycol-polypropylene glycol block copolymer, sodium citrate, sulfonated polysulfone, and isothiazolinone derivative to the water in sequence, and stir until completely dissolved; then add aminated carbon quantum dot dispersion and alkaline silica-alumina sol, and stir continuously at 1000 rpm for 16 minutes to form an aqueous dispersion; transfer the aqueous dispersion to an emulsifier, and slowly add waterborne organosilicon modified high-temperature resistant resin emulsion at 600 rpm. After the addition is complete, increase the speed to 3000 rpm for high-speed shearing for 12 minutes to form an emulsion base liquid; adjust the base liquid speed to 600 rpm, and slowly add caprolactam blocked diphenylmethane diisocyanate, shale inhibitor and polyether modified organosilicon defoamer in sequence, and continue stirring for 35 minutes to obtain the previous liquid; S2. Transfer the liquid to a mixing tank and slowly add high-temperature resistant aramid fiber at 500 rpm. After the addition is complete, increase the speed to 1000 rpm and stir for 30 minutes to obtain the sealing agent.

[0039] A photograph of the sealant after drying in this embodiment is shown below. Figure 1 As shown.

[0040] Example 2 This embodiment proposes a sealing agent comprising: 30.0g of waterborne silicone-modified high-temperature resistant resin emulsion, 2.0g of caprolactam-blocked diphenylmethane diisocyanate, 7.0g of aminated carbon quantum dot dispersion, 3.0g of alkaline silica-alumina sol, 15g of high-temperature resistant fibrous material, 2.5g of sodium dodecyl diphenyl ether disulfonate, 2.5g of polyethylene glycol-polypropylene glycol block copolymer, 1.5g of sodium citrate, 1.0g of sulfonated polysulfone, 2.5g of shale inhibitor, 0.35g of isothiazolinone derivative, 0.3g of polyether-modified silicone defoamer, and 62.77g of water. The high-temperature resistant fibrous material in this embodiment is glass fiber, and the aramid fiber has a length of 2-5mm and a diameter of 15-40μm. The shale inhibitor is polyethyleneamine, and the defoamer is a polyether-modified silicone defoamer.

[0041] This embodiment also proposes a method for preparing the above-mentioned sealing agent, including the following steps: S1. Take water according to the above dosage, heat it to 45°C and place it in a water bath; add sodium dodecyl diphenyl ether disulfonate, polyethylene glycol-polypropylene glycol block copolymer, sodium citrate, sulfonated polysulfone, and isothiazolinone derivative to the water in sequence, and stir until completely dissolved; then add aminated carbon quantum dot dispersion and alkaline silica-alumina sol, and stir continuously at 1000 rpm for 18 minutes to form an aqueous dispersion; transfer the aqueous dispersion to an emulsifier, and slowly add waterborne organosilicon modified high-temperature resistant resin emulsion at 600 rpm. After the addition is complete, increase the speed to 3000 rpm for high-speed shearing for 14 minutes to form an emulsion base liquid; adjust the base liquid speed to 700 rpm, and slowly add caprolactam blocked diphenylmethane diisocyanate, shale inhibitor and polyether modified organosilicon defoamer in sequence, and continue stirring for 40 minutes to obtain the pre-liquid; S2. Transfer the liquid to a mixing tank and slowly add high-temperature resistant aramid fiber at 600 rpm. After the addition is complete, increase the speed to 1100 rpm and stir for 35 minutes to obtain the sealing agent.

[0042] Example 3 This embodiment proposes a sealing agent comprising: 32.0g of waterborne silicone-modified high-temperature resistant resin emulsion, 3.5g of caprolactam-blocked diphenylmethane diisocyanate, 9.0g of amino-carbon quantum dot dispersion, 3.5g of alkaline silica-alumina sol, 18g of high-temperature resistant fibrous material, 2.8g of sodium dodecyl diphenyl ether disulfonate, 2.8g of polyethylene glycol-polypropylene glycol block copolymer, 1.8g of sodium citrate, 1.8g of sulfonated polysulfone, 2.8g of shale inhibitor, 0.4g of isothiazolinone derivative, 0.4g of polyether-modified silicone defoamer, and 58.57g of water. The high-temperature resistant fibrous material in this embodiment is glass fiber, and the aramid fiber has a length of 2-5mm and a diameter of 15-40μm. The shale inhibitor is polyethyleneamine, and the defoamer is a polyether-modified silicone defoamer.

[0043] This embodiment also proposes a method for preparing the above-mentioned sealing agent, including the following steps: S1. Take water according to the above dosage, heat it to 45°C and place it in a water bath; add sodium dodecyl diphenyl ether disulfonate, polyethylene glycol-polypropylene glycol block copolymer, sodium citrate, sulfonated polysulfone, and isothiazolinone derivative to the water in sequence, and stir until completely dissolved; then add aminated carbon quantum dot dispersion and alkaline silica-alumina sol, and stir continuously at 1000 rpm for 20 minutes to form an aqueous dispersion; transfer the aqueous dispersion to an emulsifier, and slowly add waterborne organosilicon modified high-temperature resistant resin emulsion at 600 rpm. After the addition is complete, increase the speed to 3000 rpm for high-speed shearing for 15 minutes to form an emulsion base liquid; adjust the base liquid speed to 700 rpm, and slowly add caprolactam blocked diphenylmethane diisocyanate, shale inhibitor and polyether modified organosilicon defoamer in sequence, and continue stirring for 45 minutes to obtain the previous liquid; S2. Transfer the liquid to a mixing tank and slowly add high-temperature resistant aramid fiber at 500 rpm. After the addition is complete, increase the speed to 1200 rpm and stir for 40 minutes to obtain the sealing agent.

[0044] Example 4 This embodiment proposes a sealing agent comprising: 25.0g of waterborne silicone-modified high-temperature resistant resin emulsion, 1.0g of caprolactam-blocked diphenylmethane diisocyanate, 7.0g of amino-carbon quantum dot dispersion, 3.0g of alkaline silica-alumina sol, 10g of high-temperature resistant fibrous material, 2.5g of sodium dodecyl diphenyl ether disulfonate, 2.5g of polyethylene glycol-polypropylene glycol block copolymer, 1.5g of sodium citrate, 1.5g of sulfonated polysulfone, 2.5g of shale inhibitor, 0.35g of isothiazolinone derivative, 0.3g of polyether-modified silicone defoamer, and 63.77g of water. The high-temperature resistant fibrous material in this embodiment is glass fiber, and the aramid fiber has a length of 2-5mm and a diameter of 15-40μm. The shale inhibitor is polyethyleneamine, and the defoamer is a polyether-modified silicone defoamer.

[0045] This embodiment also proposes a method for preparing the above-mentioned sealing agent, including the following steps: S1. Take water according to the above dosage, heat it to 45°C and place it in a water bath; add sodium dodecyl diphenyl ether disulfonate, polyethylene glycol-polypropylene glycol block copolymer, sodium citrate, sulfonated polysulfone, and isothiazolinone derivative to the water in sequence, and stir until completely dissolved; then add aminated carbon quantum dot dispersion and alkaline silica-alumina sol, and stir continuously at 1000 rpm for 18 minutes to form an aqueous dispersion; transfer the aqueous dispersion to an emulsifier, and slowly add waterborne organosilicon modified high-temperature resistant resin emulsion at 600 rpm. After the addition is complete, increase the speed to 3000 rpm for high-speed shearing for 14 minutes to form an emulsion base liquid; adjust the base liquid speed to 700 rpm, and slowly add caprolactam blocked diphenylmethane diisocyanate, shale inhibitor and polyether modified organosilicon defoamer in sequence, and continue stirring for 40 minutes to obtain the pre-liquid; S2. Transfer the liquid to a mixing tank and slowly add high-temperature resistant aramid fiber at 600 rpm. After the addition is complete, increase the speed to 1100 rpm and stir for 35 minutes to obtain the sealing agent.

[0046] Example 5 This embodiment proposes a sealing agent comprising: 25.0g of waterborne silicone-modified high-temperature resistant resin emulsion, 2.0g of caprolactam-blocked diphenylmethane diisocyanate, 7.0g of aminated carbon quantum dot dispersion, 3.0g of alkaline silica-alumina sol, 10g of high-temperature resistant fibrous material, 2.5g of sodium dodecyl diphenyl ether disulfonate, 2.5g of polyethylene glycol-polypropylene glycol block copolymer, 1.5g of sodium citrate, 1.5g of sulfonated polysulfone, 1.5g of shale inhibitor, 0.35g of isothiazolinone derivative, 0.2g of polyether-modified silicone defoamer, and 62.77g of water. The high-temperature resistant fibrous material in this embodiment is glass fiber, with the aramid fiber having a length of 2-5mm and a diameter of 15-40μm. The shale inhibitor is polyamine, and the defoamer is a polyether-modified silicone defoamer.

[0047] This embodiment also proposes a method for preparing the above-mentioned sealing agent, including the following steps: S1. Take water according to the above dosage, heat it to 45°C and place it in a water bath; add sodium dodecyl diphenyl ether disulfonate, polyethylene glycol-polypropylene glycol block copolymer, sodium citrate, sulfonated polysulfone, and isothiazolinone derivative to the water in sequence, and stir until completely dissolved; then add aminated carbon quantum dot dispersion and alkaline silica-alumina sol, and stir continuously at 1000 rpm for 18 minutes to form an aqueous dispersion; transfer the aqueous dispersion to an emulsifier, and slowly add waterborne organosilicon modified high-temperature resistant resin emulsion at 600 rpm. After the addition is complete, increase the speed to 3000 rpm for high-speed shearing for 14 minutes to form an emulsion base liquid; adjust the base liquid speed to 700 rpm, and slowly add caprolactam blocked diphenylmethane diisocyanate, shale inhibitor and polyether modified organosilicon defoamer in sequence, and continue stirring for 40 minutes to obtain the pre-liquid; S2. Transfer the liquid to a mixing tank and slowly add high-temperature resistant aramid fiber at 600 rpm. After the addition is complete, increase the speed to 1100 rpm and stir for 35 minutes to obtain the sealing agent.

[0048] Example 6 This embodiment proposes a sealing agent comprising: 25.0g of waterborne silicone-modified high-temperature resistant resin emulsion, 2.0g of caprolactam-blocked diphenylmethane diisocyanate, 3.0g of aminated carbon quantum dot dispersion, 3.0g of alkaline silica-alumina sol, 10g of high-temperature resistant fibrous material, 2.5g of sodium dodecyl diphenyl ether disulfonate, 2.5g of polyethylene glycol-polypropylene glycol block copolymer, 1.5g of sodium citrate, 1.5g of sulfonated polysulfone, 1.5g of shale inhibitor, 0.35g of isothiazolinone derivative, 0.2g of polyether-modified silicone defoamer, and 64.77g of water. The high-temperature resistant fibrous material in this embodiment is glass fiber, with the aramid fiber having a length of 2-5mm and a diameter of 15-40μm. The shale inhibitor is polyamine, and the defoamer is a polyether-modified silicone defoamer.

[0049] This embodiment also proposes a method for preparing the above-mentioned sealing agent, including the following steps: S1. Take water according to the above dosage, heat it to 45°C and place it in a water bath; add sodium dodecyl diphenyl ether disulfonate, polyethylene glycol-polypropylene glycol block copolymer, sodium citrate, sulfonated polysulfone, and isothiazolinone derivative to the water in sequence, and stir until completely dissolved; then add aminated carbon quantum dot dispersion and alkaline silica-alumina sol, and stir continuously at 1000 rpm for 18 minutes to form an aqueous dispersion; transfer the aqueous dispersion to an emulsifier, and slowly add waterborne organosilicon modified high-temperature resistant resin emulsion at 600 rpm. After the addition is complete, increase the speed to 3000 rpm for high-speed shearing for 14 minutes to form an emulsion base liquid; adjust the base liquid speed to 700 rpm, and slowly add caprolactam blocked diphenylmethane diisocyanate, shale inhibitor and polyether modified organosilicon defoamer in sequence, and continue stirring for 40 minutes to obtain the pre-liquid; S2. Transfer the liquid to a mixing tank and slowly add high-temperature resistant aramid fiber at 600 rpm. After the addition is complete, increase the speed to 1100 rpm and stir for 35 minutes to obtain the sealing agent.

[0050] Example 7 This embodiment proposes a sealing agent comprising: 30.0g of waterborne silicone-modified high-temperature resistant resin emulsion, 3.0g of caprolactam-blocked diphenylmethane diisocyanate, 7.0g of aminated carbon quantum dot dispersion, 3.0g of alkaline silica-alumina sol, 15g of high-temperature resistant fibrous material, 2.5g of sodium dodecyl diphenyl ether disulfonate, 2.5g of polyethylene glycol-polypropylene glycol block copolymer, 1.5g of sodium citrate, 1.5g of sulfonated polysulfone, 2.5g of shale inhibitor, 0.35g of isothiazolinone derivative, 0.3g of polyether-modified silicone defoamer, and 62.77g of water. The high-temperature resistant fibrous material in this embodiment is aramid fiber, with a length of 2-5mm and a diameter of 15-40μm. The shale inhibitor is polyetheramine, and the defoamer is a polyether-modified silicone defoamer.

[0051] This embodiment also proposes a method for preparing the above-mentioned sealing agent, including the following steps: S1. Take water according to the above dosage, heat it to 45°C and place it in a water bath; add sodium dodecyl diphenyl ether disulfonate, polyethylene glycol-polypropylene glycol block copolymer, sodium citrate, sulfonated polysulfone, and isothiazolinone derivative to the water in sequence, and stir until completely dissolved; then add aminated carbon quantum dot dispersion and alkaline silica-alumina sol, and stir continuously at 1000 rpm for 18 minutes to form an aqueous dispersion; transfer the aqueous dispersion to an emulsifier, and slowly add waterborne organosilicon modified high-temperature resistant resin emulsion at 600 rpm. After the addition is complete, increase the speed to 3000 rpm for high-speed shearing for 14 minutes to form an emulsion base liquid; adjust the base liquid speed to 700 rpm, and slowly add caprolactam blocked diphenylmethane diisocyanate, shale inhibitor and polyether modified organosilicon defoamer in sequence, and continue stirring for 40 minutes to obtain the pre-liquid; S2. Transfer the liquid to a mixing tank and slowly add high-temperature resistant aramid fiber at 600 rpm. After the addition is complete, increase the speed to 1100 rpm and stir for 35 minutes to obtain the sealing agent.

[0052] Example 8 This embodiment proposes a sealing agent comprising: 30.0g of waterborne silicone-modified high-temperature resistant resin emulsion, 3.0g of caprolactam-blocked diphenylmethane diisocyanate, 11.0g of amino-carbon quantum dot dispersion, 3.0g of alkaline silica-alumina sol, 15g of high-temperature resistant fibrous material, 2.5g of sodium dodecyl diphenyl ether disulfonate, 2.5g of polyethylene glycol-polypropylene glycol block copolymer, 1.5g of sodium citrate, 1.5g of sulfonated polysulfone, 2.5g of shale inhibitor, 0.35g of isothiazolinone derivative, 0.3g of polyether-modified silicone defoamer, and 60.77g of water. The high-temperature resistant fibrous material in this embodiment is aramid fiber, with a length of 2-5mm and a diameter of 15-40μm. The shale inhibitor is polyetheramine, and the defoamer is a polyether-modified silicone defoamer.

[0053] This embodiment also proposes a method for preparing the above-mentioned sealing agent, including the following steps: S1. Take water according to the above dosage, heat it to 45°C and place it in a water bath; add sodium dodecyl diphenyl ether disulfonate, polyethylene glycol-polypropylene glycol block copolymer, sodium citrate, sulfonated polysulfone, and isothiazolinone derivative to the water in sequence, and stir until completely dissolved; then add aminated carbon quantum dot dispersion and alkaline silica-alumina sol, and stir continuously at 1000 rpm for 18 minutes to form an aqueous dispersion; transfer the aqueous dispersion to an emulsifier, and slowly add waterborne organosilicon modified high-temperature resistant resin emulsion at 600 rpm. After the addition is complete, increase the speed to 3000 rpm for high-speed shearing for 14 minutes to form an emulsion base liquid; adjust the base liquid speed to 700 rpm, and slowly add caprolactam blocked diphenylmethane diisocyanate, shale inhibitor and polyether modified organosilicon defoamer in sequence, and continue stirring for 40 minutes to obtain the pre-liquid; S2. Transfer the liquid to a mixing tank and slowly add high-temperature resistant aramid fiber at 600 rpm. After the addition is complete, increase the speed to 1100 rpm and stir for 35 minutes to obtain the sealing agent.

[0054] Example 9 This embodiment proposes a sealing agent comprising: 28.0g of waterborne silicone-modified high-temperature resistant resin emulsion, 2.5g of caprolactam-blocked diphenylmethane diisocyanate, 7.0g of amino-carbon quantum dot dispersion, 2.5g of alkaline silica-alumina sol, 12g of high-temperature resistant fibrous material, 2.2g of sodium dodecyl diphenyl ether disulfonate, 2.2g of polyethylene glycol-polypropylene glycol block copolymer, 1.2g of sodium citrate, 1.2g of sulfonated polysulfone, 2.0g of shale inhibitor, 0.3g of isothiazolinone derivative, 0.2g of polyether-modified silicone defoamer, and 64.47g of water. The high-temperature resistant fibrous material in this embodiment is aramid fiber, with a length of 2-5mm and a diameter of 15-40μm. The shale inhibitor is polyetheramine, and the defoamer is a polyether-modified silicone defoamer.

[0055] This embodiment also proposes a method for preparing the above-mentioned sealing agent, including the following steps: S1. Take water according to the above dosage, heat it to 45°C and place it in a water bath; add sodium dodecyl diphenyl ether disulfonate, polyethylene glycol-polypropylene glycol block copolymer, sodium citrate, sulfonated polysulfone, and isothiazolinone derivative to the water in sequence, and stir until completely dissolved; then add aminated carbon quantum dot dispersion and alkaline silica-alumina sol, and stir continuously at 1000 rpm for 18 minutes to form an aqueous dispersion; transfer the aqueous dispersion to an emulsifier, and slowly add waterborne organosilicon modified high-temperature resistant resin emulsion at 600 rpm. After the addition is complete, increase the speed to 3000 rpm for high-speed shearing for 12 minutes to form an emulsion base liquid; adjust the base liquid speed to 650 rpm, and slowly add caprolactam blocked diphenylmethane diisocyanate, shale inhibitor and polyether modified organosilicon defoamer in sequence, and continue stirring for 40 minutes to obtain the previous liquid; S2. Transfer the liquid to a mixing tank and slowly add high-temperature resistant aramid fiber at 550 rpm. After the addition is complete, increase the speed to 1100 rpm and stir for 35 minutes to obtain the sealing agent.

[0056] Comparative Example 1 This comparative example presents a sealing agent prepared by the following steps: Take 76.47g of water, heat it to 45℃ and place it in a water bath; add 2.2g of sodium dodecyl diphenyl ether disulfonate, 2.2g of polyethylene glycol-polypropylene glycol block copolymer, 1.2g of sodium citrate, 1.2g of sulfonated polysulfone, and 0.3g of isothiazolinone derivative to the water in sequence, and stir until completely dissolved. Then add 7.0g of amino carbon quantum dot dispersion and 2.5g of alkaline silica-alumina sol, and stir continuously at 1000rpm for 18 minutes to form an aqueous dispersion; transfer the aqueous dispersion to an emulsifier, and slowly add 28.0g of waterborne organosilicon-modified high-temperature resistant resin emulsion at 600rpm. After the addition is complete, increase the speed to 3000rpm and shear at high speed for 12 minutes to form an emulsion base liquid. Adjust the base liquid speed to 650 rpm, and slowly add 2.5 g of caprolactam-blocked diphenylmethane diisocyanate, 2.0 g of shale inhibitor and 0.2 g of polyether-modified silicone defoamer in sequence. Continue stirring for 40 minutes to obtain the leak-sealing agent.

[0057] The high-temperature resistant fibrous material in this comparative example is aramid fiber, with a length of 2-5 mm and a diameter of 15-40 μm; the shale inhibitor is polyetheramine; and the defoamer is a polyether-modified silicone defoamer.

[0058] Comparative Example 2 This comparative example presents a sealing agent prepared by the following steps: Take 74.97g of water, heat it to 45℃ and place it in a water bath; add 2.2g of sodium dodecyl diphenyl ether disulfonate, 2.2g of polyethylene glycol-polypropylene glycol block copolymer, 1.2g of sodium citrate, 1.2g of sulfonated polysulfone, and 0.3g of isothiazolinone derivative to the water in sequence, and stir until completely dissolved. Then, directly transfer the aqueous dispersion to an emulsifier, and slowly add 28.0g of waterborne organosilicon-modified high-temperature resistant resin emulsion at 600rpm. After the addition is complete, increase the speed to 3000rpm and perform high-speed shearing for 12 minutes to form an emulsion base liquid. Adjust the base liquid speed to 650 rpm, and slowly add 2.5 g of caprolactam-blocked diphenylmethane diisocyanate, 2.0 g of shale inhibitor, and 0.2 g of polyether-modified silicone defoamer in sequence, and continue stirring for 40 minutes; then transfer to a mixing tank, and slowly add 12.0 g of high-temperature resistant glass fiber at 550 rpm. After the addition is complete, increase the speed to 1100 rpm and stir for 35 minutes to obtain the sealing agent.

[0059] The high-temperature resistant fibrous material in this comparative example is aramid fiber, with a length of 2-5 mm and a diameter of 15-40 μm; the shale inhibitor is polyetheramine; and the defoamer is a polyether-modified silicone defoamer.

[0060] Comparative Example 3 This comparative example presents a sealing agent prepared by the following steps: Take 64.47g of water, heat it to 45℃ and place it in a water bath; add 2.2g of sodium dodecyl diphenyl ether disulfonate, 2.2g of polyethylene glycol-polypropylene glycol block copolymer, 1.2g of sodium citrate, 1.2g of sulfonated polysulfone, and 0.3g of isothiazolinone derivative to the water in sequence, and stir until completely dissolved. Then add 7.0g of amino carbon quantum dot dispersion and 2.5g of alkaline silica-alumina sol, and stir continuously at 1000rpm for 18 minutes to form an aqueous dispersion; transfer the aqueous dispersion to an emulsifier, and slowly add 28.0g of waterborne organosilicon-modified high-temperature resistant resin emulsion at 600rpm. After the addition is complete, increase the speed to 3000rpm and shear at high speed for 12 minutes to form an emulsion base liquid. Adjust the base liquid stirring speed to 650 rpm, and slowly add 2.5 g of diphenylmethane diisocyanate (replacing the caprolactam-blocked diphenylmethane diisocyanate in Example 9), 2.0 g of shale inhibitor, and 0.2 g of polyether-modified silicone defoamer in sequence, and continue stirring for 40 minutes. Then transfer to a mixing tank, slowly add 12.0 g of high-temperature resistant glass fiber at 550 rpm, and after the addition is complete, increase the speed to 1100 rpm and stir for 35 minutes to obtain the sealing agent.

[0061] The high-temperature resistant fibrous material in this comparative example is aramid fiber, with a length of 2-5 mm and a diameter of 15-40 μm; the shale inhibitor is polyetheramine; and the defoamer is a polyether-modified silicone defoamer.

[0062] Related experiments (1) Compressive strength test: The sealing agents prepared in each example and comparative example were injected into a cylindrical stainless steel mold with an inner diameter of 2 cm, placed in a high-temperature and high-pressure curing autoclave, and cured for 4 h at 230℃ and 10 MPa. The solidified sealing agent was removed, processed into a standard cylinder with a length of 10 cm, and after grinding both ends flat, it was placed between the two pressure plates of a universal testing machine (model: ST-5000N). A loading speed of 10 mm / min was applied, and the maximum pressure at which the solidified body broke was recorded, which is its compressive strength. Each sample was tested in parallel three times, and the average value was taken. The results are shown in Table 1.

[0063] (2) Permeability coefficient test: A dynamic evaluation device for fracture sealing was used. Artificial fracture cores with an inner diameter of 2.5 cm and a length of 10 cm were placed into a core holder and preheated to 230℃. The sealing agent was injected into the fracture at a flow rate of 0.5 L / min and cured at 230℃ and 10 MPa for 4 h. Subsequently, using water as the experimental fluid, displacement pressure differentials of 4 MPa, 5 MPa, and 6 MPa were applied at 25℃, and each pressure point was stabilized for 10 min. The flow rate was recorded, and the fracture permeability (unit: mD) was calculated. The results are shown in Table 2.

[0064] Table 1. Test results of compressive strength of self-adhesive sealant solidified body Table 2. Test results of sealing performance of ultra-high temperature self-adhesive sealant Test results show that the plugging agent prepared in this invention exhibits excellent comprehensive performance after curing at 230℃. The compressive strength of the examples is generally higher than 15 MPa, reaching a maximum of 20.5 MPa, and the permeability of the fractures after plugging under a displacement pressure difference of 6 MPa is less than 0.25 mD, achieving efficient sealing. In contrast, the compressive strength of Comparative Examples 1 and 2 is significantly reduced, and the permeability under high pressure increases sharply, resulting in plugging failure; although Comparative Example 3 has a certain strength, its plugging stability is still far inferior to that of the examples of this invention. These comparisons fully verify the key role of the three-level synergistic mechanism of "fiber bridging-thermal triggered delayed bonding-nano reinforcement". Among them, Example 9 achieves the best balance between compressive strength and high-pressure plugging performance, demonstrating the significant advantages of this invention in dealing with high-temperature fracture leakage in ultra-deep wells, combining high strength, high plugging efficiency, and good construction safety.

[0065] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A sealant, characterized in that, The composition, by weight, includes: 22-32 parts of waterborne silicone-modified high-temperature resistant resin emulsion, 1.8-3.5 parts of caprolactam-blocked diphenylmethane diisocyanate, 4-9 parts of aminated carbon quantum dot dispersion, 1.8-3.5 parts of alkaline silica-alumina sol, 8-18 parts of high-temperature resistant fibrous material, 1.5-2.8 parts of sodium dodecyl diphenyl ether disulfonate, 1.5-2.8 parts of polyethylene glycol-polypropylene glycol block copolymer, 0.8-1.8 parts of sodium citrate, 0.8-1.8 parts of sulfonated polysulfone, 1.2-2.8 parts of shale inhibitor, 0.2-0.4 parts of isothiazolinone derivative, 0.15-0.4 parts of defoamer, and 60-65 parts of water.

2. The sealing agent according to claim 1, characterized in that, The composition, by weight, includes: 25-30 parts of waterborne silicone-modified high-temperature resistant resin emulsion, 2.0-3.0 parts of caprolactam-blocked diphenylmethane diisocyanate, 6-8 parts of aminated carbon quantum dot dispersion, 2.0-3.0 parts of alkaline silica-alumina sol, 10-15 parts of high-temperature resistant fibrous material, 2.0-2.5 parts of sodium dodecyl diphenyl ether disulfonate, 2.0-2.5 parts of polyethylene glycol-polypropylene glycol block copolymer, 1.0-1.5 parts of sodium citrate, 1.0-1.5 parts of sulfonated polysulfone, 1.5-2.5 parts of shale inhibitor, 0.25-0.35 parts of isothiazolinone derivative, 0.2-0.3 parts of defoamer, and 58-68 parts of water.

3. The sealing agent according to claim 2, characterized in that, The composition, by weight, includes: 28 parts of waterborne silicone-modified high-temperature resistant resin emulsion, 2.5 parts of caprolactam-blocked diphenylmethane diisocyanate, 7 parts of aminated carbon quantum dot dispersion, 2.5 parts of alkaline silica-alumina sol, 12 parts of high-temperature resistant fibrous material, 2.2 parts of sodium dodecyl diphenyl ether disulfonate, 2.2 parts of polyethylene glycol-polypropylene glycol block copolymer, 1.2 parts of sodium citrate, 1.2 parts of sulfonated polysulfone, 2.0 parts of shale inhibitor, 0.3 parts of isothiazolinone derivative, 0.2 parts of polyether-modified silicone defoamer, and 64.47 parts of water.

4. The sealing agent according to any one of claims 1-3, characterized in that, The high-temperature resistant fibrous material is one or both of aramid fiber and glass fiber.

5. The sealing agent according to claim 4, characterized in that, The high-temperature resistant fibrous material has a length of 2-5 mm and a diameter of 15-40 μm.

6. The sealing agent according to any one of claims 1-3, characterized in that, The shale inhibitor is one or more of polyetheramine, polyamine, or polyethyleneamine; and / or the defoamer is a polyether-modified silicone defoamer.

7. A method for preparing the sealing agent according to any one of claims 1-6, characterized in that, Includes the following steps: S1. Preparation of the precursor solution: Heat the prescribed amount of water to 40-50℃, and add sodium dodecyl diphenyl ether disulfonate, polyethylene glycol-polypropylene glycol block copolymer, sodium citrate, sulfonated polysulfone, and isothiazolinone derivative in sequence while stirring until completely dissolved; then add aminated carbon quantum dot dispersion and alkaline silica-alumina sol and continue stirring to form an aqueous dispersion; transfer the obtained aqueous dispersion to an emulsification device, add waterborne organosilicon-modified high-temperature resistant resin emulsion while stirring, and then shear emulsify to form an emulsion base liquid; then add shale inhibitor and defoamer in sequence while stirring to obtain the precursor solution; S2. Composite preparation of sealing agent: The precursor liquid obtained in step S1 is transferred to a mixing tank. Under stirring, the formulated amount of high-temperature resistant fibrous material is added to the precursor liquid and stirred to obtain the sealing agent.

8. The method for preparing the sealing agent according to claim 7, characterized in that, In step S1, the aqueous dispersion is formed by continuous stirring for 15-20 min; and / or, in step S1, the emulsion is formed by shear emulsification for 10-15 min.

9. The application of a plugging agent according to any one of claims 1-6 or a plugging agent prepared by the preparation method according to any one of claims 7-8 in drilling fracture leakage.

10. The application according to claim 9, characterized in that, include: The plugging agent is added at 5%-12% of the total volume of the drilling fluid and pumped into the target lost circulation zone downhole through the drilling fluid circulation system.

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