Environment-friendly methyl methacrylate composite plugging agent and preparation method thereof

Abstract

The invention discloses an environment-friendly methyl methacrylate composite plugging agent and a preparation method thereof. The composite plugging agent comprises the following raw materials in parts by mass: 40-60 parts of methyl methacrylate; 10 to 20 parts of chlorosulfonated polyethylene; 0.5 to 2 parts of an initiator; 0.1 to 0.5 part of a stabilizing agent; 20 to 30 parts of a filling agent; 5-10 parts of a plasticizer; the filling agent is formed by mixing calcium carbonate and talcum powder according to the mass ratio of 1: 1. The composite plugging agent disclosed by the invention is high in compressive strength and can adapt to various complex plugging scenes.

Description

Technical Field

[0001] The invention relates to the technical field of plugging agent materials, and in particular to an environmentally friendly methyl methacrylate composite plugging agent and a preparation method thereof. Background Art

[0002] With the growing demand for plugging in various industries, the development of efficient and environmentally friendly plugging agents has become a key issue. Traditional plugging agents have exposed many problems in practical applications.

[0003] As oil and gas exploration and development advance into deeper and more complex formations, drilling fluid leakage has become a key factor affecting drilling safety and operational efficiency. During the drilling process, complex geological conditions such as formation fractures and porous formations often lead to drilling fluid leakage, increasing drilling costs, reducing drilling efficiency, and even causing downhole accidents. Traditional cement-based plugging agents, while able to plug leaks to a certain extent, have many limitations. Cement-based plugging agents are brittle after curing and are prone to cracking when faced with complex geological stress changes, frequent groundwater flushing, and vibrations during construction, resulting in poor plugging effects. In addition, cement-based plugging agents take a long time to cure and have low construction efficiency, making them difficult to meet some emergency plugging needs.

[0004] In the construction industry, wall cracks and roof leaks are common problems. While some asphalt-based sealing materials may initially be effective, they lack durability and are susceptible to aging, softening, and loss of sealing properties due to exposure to UV radiation, rain, and seasonal temperature fluctuations. A review of modern building waterproofing and sealing technologies indicates that buildings using asphalt-based sealing agents have a recurrence rate of up to 30% to 40% within two to three years. This is due to the limited weather resistance of asphalt itself and its insufficient bond with the building substrate.

[0005] In the water conservancy sector, leaks in structures like dams and sluice gates place extremely high demands on the environmental performance of traditional leak-proofing agents. However, some chemical leak-proofing agents contain toxic volatile organic compounds (VOCs) such as benzene and phenols. When exposed to large amounts of flowing water, these compounds slowly leach harmful substances, polluting the aquatic ecosystem. According to the "Current Status and Challenges of Environmentally Friendly Materials in Water Conservancy Projects," following leak-proofing projects in some small reservoirs, fish deaths and abnormal algae growth have been reported in surrounding waters. This has been linked to the release of pollutants from the leak-proofing agents used. These leak-proofing agents focus solely on short-term effectiveness while ignoring long-term environmental impacts.

[0006] To sum up, existing plugging agents generally have shortcomings such as unsatisfactory plugging effect, poor durability and poor environmental performance. They are difficult to meet the comprehensive demand for plugging materials in multiple fields such as drilling engineering, construction, and water conservancy. A new plugging technology solution is urgently needed to overcome these problems. Summary of the Invention

[0007] In order to overcome the deficiencies in the prior art, the present invention proposes an environmentally friendly methyl methacrylate composite plugging agent and a preparation method thereof, aiming to solve the problems of poor plugging effect, environmental pollution and insufficient durability of existing plugging agents.

[0008] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0009] On the one hand, an environmentally friendly methyl methacrylate composite plugging agent is provided, comprising the following raw materials in parts by weight:

[0010] 40-60 parts of methyl methacrylate;

[0011] 10-20 parts of chlorosulfonated polyethylene;

[0012] 0.5-2 parts of initiator;

[0013] Stabilizer 0.1-0.5 parts;

[0014] 20-30 parts of filler;

[0015] 5-10 parts of plasticizer;

[0016] The filler is a mixture of calcium carbonate and talc in a mass ratio of 1:1.

[0017] Furthermore, the initiator is benzoyl peroxide.

[0018] Furthermore, the stabilizer is hydroquinone with a purity of ≥99wt%.

[0019] Furthermore, the calcium carbonate is light calcium carbonate with a particle size of 1000 mesh and a water content of <0.5wt%.

[0020] Furthermore, the talcum powder has a particle size of 1200 mesh and a water content of <0.5 wt%.

[0021] Furthermore, the plasticizer is dibutyl phthalate with a purity of ≥99wt%.

[0022] Furthermore, the purity of the methyl methacrylate is ≥98 wt%.

[0023] The sealant in this invention uses methyl methacrylate as its core monomer. Its molecular chains possess efficient cross-linking activity, enabling rapid and dense bonding to form a robust three-dimensional polymer network. Upon encountering a leak, this polymer network, through its adhesive properties, adheres tightly to a variety of common leak-causing substrates, such as metal, ceramic, and concrete, creating a high-strength sealing barrier.

[0024] The chlorosulfonated polyethylene (CSP) of the present invention is a polymer compound with a unique molecular structure design. It contains chlorine atoms and sulfonyl chloride functional groups, which endow it with excellent tolerance to high temperatures and adverse climatic conditions. On the one hand, due to its chemical structure characteristics, CSP can effectively block the diffusion and penetration path of hot oxygen molecules into the plugging agent, fundamentally inhibiting the material's oxidative degradation process, ensuring that the plugging agent will not fail due to embrittlement or flaking over a long period of time, maintaining the integrity and stability of the overall structure. On the other hand, the polar groups on its molecular chain can chemically bond or physically adsorb with active chemical sites on the surface of the plugged substrate, greatly enhancing the interfacial bonding between the plugging agent and the substrate.

[0025] The present invention uses benzoyl peroxide as an initiator to initiate the polymerization reaction of methyl methacrylate. From a microscopic perspective, upon addition of the initiator benzoyl peroxide, the methyl methacrylate monomer molecules are activated, and the previously relatively independent methyl methacrylate spheres begin to chemically bond. As the reaction proceeds, the number of active intermediates gradually increases, and the molecular chains continue to grow, ultimately forming a compact three-dimensional polymer network structure. By appropriately increasing the amount of benzoyl peroxide added, the polymerization reaction rate can be precisely controlled, rapidly initiating and efficiently advancing the polymerization process.

[0026] As ambient temperature rises, the intramolecular energy and activity of methyl methacrylate monomer increase, making it prone to spontaneous polymerization, a phenomenon known as autopolymerization. This can lead to premature failure of the raw material, preventing it from participating in the polymerization reaction to form an effective leak-proof sealing layer during the intended operation phase. The present invention uses hydroquinone as a polymerization stabilizer. By forming specific weak interactions with the monomer molecules, such as hydrogen bonding and π-π stacking, it precisely regulates the activity state of the monomer molecules and effectively suppresses the probability of autopolymerization.

[0027] From the perspective of cost control, the present invention introduces calcium carbonate and talcum powder as fillers, which can effectively reduce the cost of raw material procurement while ensuring the core performance of the plugging agent. Especially in large-scale industrial plugging projects or frequent plugging operation demand scenarios, this cost optimization strategy has the advantage of greatly improving the economy and feasibility of plugging and repairing operations. On the one hand, calcium carbonate, as an inorganic rigid filling material with excellent thermal stability, can provide the necessary mechanical support for the overall structure of the plugging agent. On the other hand, calcium carbonate, by virtue of its own rigidity, can effectively disperse stress concentration areas and prevent the plugging agent material from cracking, deformation and other structural failure problems as a whole. Talc relies on its fine particle texture, excellent lubricity and good dispersion characteristics to ensure that the plugging agent has good rheological properties during the mixing preparation and on-site construction application process, ensuring that each component is evenly dispersed and synergistic. The two complement each other and jointly ensure that the plugging agent stably and long-lastingly exerts its plugging and sealing effect.

[0028] The present invention uses dibutyl phthalate as a plasticizer, enabling precise control of the rigid structure of the cured plugging agent. Its mechanism of action lies in the fact that during the polymerization and curing process, dibutyl phthalate molecules can embed themselves between polymer chains, increasing the distance between these chains and imparting a degree of elastic deformation to the plugging agent. This structure acts like a spring with an elastic buffer mechanism, allowing it to adaptively expand and contract, effectively preventing cracks and maintaining a stable seal.

[0029] On the other hand, a method for preparing an environmentally friendly methyl methacrylate composite plugging agent is provided, comprising the following steps:

[0030] S1. Divide methyl methacrylate into two parts;

[0031] S2. Slowly add the chlorosulfonated polyethylene to the first portion of methyl methacrylate and place the mixture in a reactor. Stir at a speed of 300 r / min for 30-40 min until the mixture is uniformly stirred to form a mixed solution.

[0032] S3. Dissolve the initiator and stabilizer in the second portion of methyl methacrylate, then slowly add the mixture to the mixture and continue stirring for 10-15 minutes;

[0033] S4. Add the filler and plasticizer into the reactor in sequence, increase the stirring speed to 500 r / min and stir for 20-30 minutes until a uniform, lump-free paste is formed. The paste is the methyl methacrylate composite plugging agent.

[0034] Furthermore, in S1, the mass ratio of the first part of methyl methacrylate to the second part of methyl methacrylate is 5:1; in S2, the stirring time is 35 minutes; in S3, the initiator and stabilizer are added to the second part of methyl methacrylate and then dissolved using magnetic stirring at room temperature, and the magnetic stirring time at room temperature is 3-5 minutes; in S4, the filler is added using a vacuum feeding device, and the stirring time after adding the filler and plasticizer is 25 minutes.

[0035] In S2, the dispersion of the chlorosulfonated polyethylene is closely observed. If agglomeration is found, the feeding rate can be appropriately reduced and the stirring time can be extended by 5 to 10 minutes to ensure that the chlorosulfonated polyethylene is evenly integrated into the methyl methacrylate.

[0036] In S4, a vacuum feeding device is used to add the filler to prevent dust from flying and causing loss of raw materials and environmental pollution.

[0037] In S4, during the process of adding filler and plasticizer and stirring, the state of the materials in the reactor is constantly observed. If lumps are found, stirring can be stopped and manually assisted with stirring with a glass rod or other tool to disperse the lumps, and then stirring can be continued until a uniform paste without lumps is obtained.

[0038] After the environmentally friendly methyl methacrylate composite leak-proof agent of the present invention is prepared and reaches uniform, agglomerate-free, and uniform color, it is immediately sealed in aluminum foil bags to ensure the tightness of the packaging and prevent the leak-proof agent from prolonged contact with air, which could prevent premature curing. The packaged leak-proof agent is stored in a cool, dry place with a temperature controlled at 20-25°C and a relative humidity of 40%-60%. It is also properly labeled with key information such as the product name, batch, production date, and shelf life.

[0039] The method for using the environmentally friendly methyl methacrylate composite plugging agent prepared by the present invention comprises the following steps:

[0040] S100. Pre-construction Preparation: Before beginning leak plugging operations, conduct a comprehensive and detailed survey of the construction site to accurately determine the leak source's location, extent, and surrounding environmental conditions. For areas with flammable or explosive hazards, eliminate all potential fire sources and static electricity hazards. Additionally, prepare appropriate auxiliary materials based on the material characteristics of the leaking area. For example, prepare an anti-rust primer for metal pipes and an adhesive for concrete structures.

[0041] S200, refinement of surface pretreatment: If the leak is seriously oily, soak and scrub it with an oil cleaner first, then rinse it with hot water to ensure that the oil removal rate reaches more than 95%; for areas with a lot of dust accumulation, use a high-power vacuum cleaner to first remove most of the dust, then use a high-pressure air gun to blow away the remaining dust to ensure that there are no visible dust particles attached to the surface; for rust problems, in addition to sanding to the arithmetic mean deviation (Ra) of the surface roughness between 0.5μm and 1.0μm, you can also use a rust remover for chemical rust removal, then rinse thoroughly with clean water and wipe dry with a clean rag to create a clean, dry and rough surface for the application of the plugging agent, thereby maximizing the bonding effect between the plugging agent and the substrate.

[0042] S300. Optimization of leak-proof agent preparation: If the leak-proof agent is stored for a long time, in addition to gently stirring it to ensure that the components are evenly distributed before use, its rheological properties should be tested with a professional rheometer to ensure that its viscosity is in the optimal construction range. If the viscosity is found to be too high, a small amount of special diluent can be added in an appropriate amount and stirred slowly and evenly. Note that the amount of diluent added must not exceed 3wt% of the total mass of the leak-proof agent to prevent affecting the performance of the leak-proof agent. If there is slight agglomeration, restore it to a uniform state by low-speed stirring or rolling. The operation should be carried out in a vacuum environment or a low-humidity environment (humidity less than 30%) to avoid the introduction of too much water vapor that may cause the leak-proof agent to deteriorate. At the same time, monitor the stirring or rolling force throughout the process to prevent damage to the internal structure of the leak-proof agent.

[0043] S400, Operation Expansion: In mining operations, due to the complex geological conditions, spray gun application is not suitable and special processes are required. For example, segmented pumping of plugging agents is used. Based on the detection results of the leak location on the well wall, specialized pumping equipment is used to deliver the plugging agent in sections at a calculated volume and pressure to precisely control its distribution.

[0044] S500, Strengthening of curing and maintenance: After the construction work is completed, in an environment with normal temperature (20-25°C) and relative humidity of 40%-60%, in addition to routine maintenance for 24-36 hours, non-destructive testing equipment (such as ultrasonic flaw detectors, infrared thermal imagers, etc.) should be used every 6 hours to monitor the curing status of the plugging parts, and the curing process of the internal structure of the plugging agent should be grasped in real time. If local curing is found to be poor, remedial measures should be taken in time, such as local heating or adding a small amount of plugging agent. If the ambient temperature is low (below 15°C), when using heating equipment (such as infrared lamps, electric heaters, etc.) to locally heat the plugging parts, it is necessary to combine temperature sensors with automatic temperature control devices to accurately control the heating temperature at 30-40°C to ensure uniform heating and avoid degradation of the plugging agent performance due to excessively high temperature. After maintenance is completed, in addition to routine inspections such as pressure testing and leakage observation, durability testing should also be carried out to simulate the actual use environment (such as temperature cycle, humidity changes, medium erosion, etc.), and the plugging effect should be continuously observed for at least 72 hours to ensure the long-term stability and success of the plugging operation.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] 1. This invention uses methyl methacrylate as the core monomer, which, under the action of an initiator, can quickly and efficiently form a dense polymer network structure. This polymer network structure gives the plugging agent extremely strong adhesion, enabling it to tightly adhere to the surface of various leaking areas, achieving precise filling and sealing of both tiny cracks and larger holes.

[0047] The addition of chlorosulfonated polyethylene further optimizes the plugging effect. Its unique molecular structure enhances the interfacial bonding strength between the plugging agent and the material to be plugged, allowing the plugging agent to remain firmly attached and sealed even under complex working conditions, greatly reducing the risk of secondary leakage.

[0048] 2. The rational application of the filler in this invention provides a solid physical support structure for the plugging agent. The filler not only enhances the compressive strength of the plugging agent, enabling it to withstand long-term external pressure shocks, but also optimizes the material's wear resistance, reducing losses due to water erosion and medium friction. The plugging agent's structural integrity is retained at a rate of over 90%, ensuring long-term, stable plugging performance.

[0049] The precise combination of stabilizer and initiator strictly controls the polymerization reaction process, so that the plugging agent maintains good stability during preparation and storage, avoids performance degradation caused by premature polymerization or degradation, and lays the foundation for its long-term use.

[0050] 3. The raw materials used in the present invention all meet strict environmental protection standards. Methyl methacrylate itself has relatively low volatile organic compound (VOC) emissions and will not cause significant pollution to the surrounding air environment during use. At the same time, when in contact with groundwater or other water bodies, the components in the plugging agent will not dissolve harmful substances, ensuring the safety of water resources. According to measurements by professional environmental protection testing agencies, the amount of heavy metals dissolved in the plugging agent is less than 10% of the national standard limit, and its toxic effect on aquatic organisms is negligible. It can be widely used in fields with extremely high environmental protection requirements, such as water conservancy projects near water sources, urban drinking water pipelines and other plugging operations.

[0051] 4. The leak-proof agent of the present invention is adaptable to various complex leak-proofing scenarios. Whether it is high-temperature industrial pipelines, high-humidity basements, strong acid and alkali chemical containers, tiny cracks in building walls, or leaks in underwater facilities, efficient leak-proofing can be achieved by simply adjusting the leak-proof agent's composition, preparation process, or application steps according to the actual situation. For example, in underwater leak-proofing scenarios, the optimized leak-proof agent can be successfully applied underwater at depths of up to 50 meters, achieving a long-lasting and reliable sealing effect.

[0052] 5. The use of the leak-proof agent of the present invention effectively reduces material costs, significantly saving material procurement expenses in large-scale leak-proofing projects. Furthermore, due to its high efficiency and long-lasting performance, the leak-proof agent reduces the manpower, material, and time costs associated with frequent repairs and secondary leak-proofing. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0054] In the embodiment of the present invention, methyl methacrylate is selected from products with a purity of 98.5 wt % as detected by a high-precision chromatographic analyzer, ensuring its stable quality and the absence of obvious impurities, moisture or other substances that may affect the polymerization reaction.

[0055] In the embodiment of the present invention, the chlorosulfonated polyethylene is selected to meet industrial standards and have a moderate Mooney viscosity, and is ensured to be free of impurities through visual inspection and chemical analysis of samples.

[0056] In the embodiment of the present invention, the accuracy of benzoyl peroxide is controlled within ±0.05 parts, and the product is sealed and stored in a cool and dry place to prevent partial decomposition and failure due to prolonged exposure to air or light.

[0057] In the embodiment of the present invention, the purity of hydroquinone is not less than 99 wt % and is properly sealed immediately after being weighed to avoid oxidation.

[0058] In the embodiment of the present invention, both calcium carbonate and talc are dried to have a water content of less than 0.5 wt % to prevent adverse reactions caused by moisture during the subsequent mixing process.

[0059] In the embodiment of the present invention, dibutyl phthalate meets relevant environmental protection standards and has a purity of more than 99 wt%.

[0060] In an embodiment of the present invention, the preparation method of the composite plugging agent comprises the following steps:

[0061] S1. Divide methyl methacrylate into two parts, with the mass ratio of the first part of methyl methacrylate to the second part of methyl methacrylate being 5:1;

[0062] S2. Slowly add chlorosulfonated polyethylene into the reactor containing the first portion of methyl methacrylate and stir evenly at a stirring speed of 300 r / min for 35 min to obtain a mixed solution;

[0063] S3. Slowly add the initiator and stabilizer to the second portion of methyl methacrylate, stir evenly with a magnetic stirrer at a stirring speed of 300 r / min for 5 min; then slowly add the solution obtained by mixing and dissolving the initiator, stabilizer and the second portion of methyl methacrylate dropwise to the mixture and continue stirring for 8 min;

[0064] S4. Add the filler and plasticizer into the reactor in sequence, increase the stirring speed to 500 r / min and stir for 25 minutes until a uniform, lump-free paste is formed. The paste is the methyl methacrylate composite plugging agent.

[0065] Example 1

[0066] As a preferred embodiment of the present invention, the specific composition of an environmentally friendly methyl methacrylate composite plugging agent disclosed in this embodiment is shown in Table 1 below.

[0067] Table 1

[0068]

[0069]

[0070] Example 2

[0071] As a preferred embodiment of the present invention, the specific composition of an environmentally friendly methyl methacrylate composite plugging agent disclosed in this embodiment is shown in Table 2 below.

[0072] Table 2

[0073] raw material Mass parts / parts Methyl methacrylate 52 Chlorosulfonated polyethylene 15 Benzoyl peroxide 0.8 hydroquinone 0.3 mixture of calcium carbonate and talc 23 Dibutyl phthalate 8.9

[0074] Example 3

[0075] As a preferred embodiment of the present invention, the specific composition of an environmentally friendly methyl methacrylate composite plugging agent disclosed in this embodiment is shown in Table 3 below.

[0076] Table 3

[0077] raw material Mass parts / parts Methyl methacrylate 45 Chlorosulfonated polyethylene 14 Benzoyl peroxide 0.8 hydroquinone 0.2 mixture of calcium carbonate and talc 30 Dibutyl phthalate 10

[0078] Example 4

[0079] As a preferred embodiment of the present invention, the specific composition of an environmentally friendly methyl methacrylate composite plugging agent disclosed in this embodiment is shown in Table 4 below.

[0080] Table 4

[0081] raw material Mass parts / parts Methyl methacrylate 56 Chlorosulfonated polyethylene 15 Benzoyl peroxide 2 hydroquinone 0.5 mixture of calcium carbonate and talc 20 Dibutyl phthalate 6.5

[0082] Comparative Example 1

[0083] The plugging agent of this comparative example only contains methyl methacrylate and initiator, and the usage ratio is the same as that of Example 1.

[0084] Comparative Example 2

[0085] The plugging agent of this comparative example is HJ510 acrylate grouting material.

[0086] Comparative Example 3

[0087] The plugging agent of this comparative example is a traditional cement plugging agent: including 80 parts by mass of ordinary Portland cement, 16 parts by mass of quartz powder, 1 part by mass of calcium chloride, 0.5 part by mass of lithium chloride, 0.5 part by mass of water reducer, 0.5 part by mass of viscosity enhancer, and 0.5 part by mass of heat stabilizer.

[0088] Test Case

[0089] Curing time test: Place the test sample in a constant temperature and humidity environment at 23℃±2℃, and use a Shore D hardness tester to test the hardness change every 1 minute. When the hardness reaches 80 or above, it is considered fully cured and the curing time is recorded.

[0090] Compressive strength test after curing: After curing, the test examples were made into standard test blocks (50 mm × 50 mm × 50 mm), cured in a constant temperature and humidity environment of 23°C ± 2°C for 28 days, and their initial compressive strength was tested using a pressure testing machine.

[0091] Aging performance test:

[0092] 1. Temperature Cycle Test: After the initial strength test, place the specimen in a temperature cycle chamber, set the temperature range to -20°C to 80°C, and perform 100 cycles. In each cycle, the specimen is maintained at -20°C for 1 hour, then heated to 80°C at a rate of 10°C / min, maintained at 80°C for 1 hour, and then cooled to -20°C at a rate of 10°C / min. After completing 100 temperature cycles, remove the specimen from the chamber and allow it to return to room temperature for 24 hours.

[0093] 2. Acid-Base Immersion Test: Immerse the cured test specimen in a 5% HCl (acidic) or 5% NaOH (alkaline) solution at 23°C ± 2°C. After immersion for 500 hours, remove the specimen from the acid-base solution, rinse with clean water, wipe dry, and allow to stand at room temperature for 24 hours.

[0094] The compressive strength of the test cases was tested before and after the temperature cycle and acid-base immersion tests. The test cases were made into standard test blocks and the compressive strength was tested using a pressure testing machine.

[0095] Strength retention rate = (compressive strength after aging / initial compressive strength) × 100%.

[0096] The curing time, initial compressive strength and aging performance of the plugging agents of Examples 1 to 4 and Comparative Examples 1 to 3 were tested. The test results are shown in Table 5 below.

[0097] Table 5

[0098]

[0099] The traditional cement plugging agent in Comparative Example 3 is a hydraulic material. Its curing process is different from that of chemical curing materials. There is no time node similar to "complete curing". Generally, its strength gradually increases through curing, so the curing time is not recorded here.

[0100] As shown in Table 5, it can be seen from the plugging agents of Examples 1 to 4 and the plugging agents of Comparative Examples 1 to 3 that the environmentally friendly methyl methacrylate composite plugging agent of the present invention has obvious advantages, its curing time is moderate and adjustable, the initial compressive strength is the highest, and the strength retention rate after temperature cycling and acid and alkali immersion is also excellent, which is due to the synergistic effect of the various components in the formula; although the HJ510 acrylate grouting material of Comparative Example 2 has a certain curing speed, initial compressive strength, aging resistance, and acid and alkali resistance, all indicators are slightly inferior; the plugging agent of Comparative Example 1 has low initial compressive strength, poor resistance to temperature cycling and acid and alkali erosion, and the simple formula leads to poor performance stability; the traditional cement plugging agent of Comparative Example 3 performs the worst in terms of initial compressive strength, strength retention rate after temperature cycling and acid and alkali immersion. Due to the limitations of its own material properties, it has obvious limitations in aging resistance and acid and alkali resistance.

[0101] The rational formula design of the environmentally friendly methyl methacrylate composite plugging agent of the present invention enables the material to have a faster curing speed, higher initial compressive strength, and good aging resistance and acid and alkali resistance, and is suitable for a variety of plugging scenarios.

[0102] Finally, it should be noted that the above embodiments are merely preferred embodiments of the present invention and are intended to illustrate the technical solutions of the present invention, rather than limiting them, and certainly not limiting the patent scope of the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features therein may be replaced by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention. In other words, any changes or refinements made to the main design concept and spirit of the present invention that have no substantive significance, provided that the technical problems they solve are still consistent with those of the present invention, should be included in the protection scope of the present invention. In addition, the direct or indirect application of the technical solutions of the present invention to other related technical fields should also be included in the patent protection scope of the present invention.

Claims

1. An environmentally friendly methyl methacrylate composite plugging agent, characterized in that: Including the following raw materials in parts by mass: 40-60 parts of methyl methacrylate; 10-20 parts of chlorosulfonated polyethylene; 0.5-2 parts of initiator; Stabilizer 0.1-0.5 parts; 20-30 parts of filler; 5-10 parts of plasticizer; The filler is a mixture of calcium carbonate and talc in a mass ratio of 1:

1.

2. An environmentally friendly methyl methacrylate composite plugging agent according to claim 1, characterized in that, The initiator is benzoyl peroxide.

3. The environmentally friendly methyl methacrylate composite plugging agent according to claim 1, characterized in that: The stabilizer is hydroquinone with a purity of ≥99wt%.

4. The environmentally friendly methyl methacrylate composite plugging agent according to claim 1, characterized in that: The calcium carbonate is light calcium carbonate with a particle size of 800-1200 mesh and a water content of less than 0.5 wt%.

5. The environmentally friendly methyl methacrylate composite plugging agent according to claim 1, characterized in that: The talc powder has a particle size of 1000-1500 mesh and a water content of less than 0.5 wt%.

6. The environmentally friendly methyl methacrylate composite plugging agent according to claim 1, characterized in that: The plasticizer is dibutyl phthalate, with a purity of ≥99wt%.

7. The environmentally friendly methyl methacrylate composite plugging agent according to claim 1, characterized in that: The purity of the methyl methacrylate is ≥98 wt %.

8. The method for preparing an environmentally friendly methyl methacrylate composite plugging agent according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Divide methyl methacrylate into two parts; S2. Slowly add the chlorosulfonated polyethylene to the first portion of methyl methacrylate and place the mixture in a reactor. Stir at a speed of 300 r / min for 30-40 min until the mixture is uniformly stirred to form a mixed solution. S3. Dissolve the initiator and stabilizer in the second portion of methyl methacrylate, then slowly add the mixture to the mixture and continue stirring for 10-15 minutes; S4. Add the filler and plasticizer into the reactor in sequence, increase the stirring speed to 500 r / min and stir for 20-30 minutes until a uniform, lump-free paste is formed. The paste is the methyl methacrylate composite plugging agent.

9. The method for preparing an environmentally friendly methyl methacrylate composite plugging agent according to claim 8, characterized in that: In S1, the mass ratio of the first part of methyl methacrylate to the second part of methyl methacrylate is 5:1; in S2, the stirring time is 35 minutes; in S3, the initiator and the stabilizer are added to the second part of methyl methacrylate and then dissolved using magnetic stirring at room temperature for 3-5 minutes; in S4, the filler is added using a vacuum feeding device, and the stirring time after adding the filler and plasticizer is 25 minutes.

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