Composite resin leaking stoppage composition as well as preparation method and application thereof

Abstract

The invention provides a composite resin leaking stoppage composition as well as a preparation method and application thereof. The composite resin leaking stoppage composition is compounded with three resins, namely water-borne epoxy resin, polyimide resin and melamine phenolic resin, and is added with a latent curing agent, a flow pattern regulator, a first cross-linking agent, a retarder and a filling agent according to a specific formula in a matched manner, so that the composite resin leaking stoppage composition has good rheological property before being cured; the plugging agent has the advantages of high temperature resistance, high compressive strength after being cured at the temperature of 240 DEG C, high pressure-bearing plugging performance on cracks and good plugging effect, and is suitable for plugging construction of ultra-deep fractured-vuggy oil reservoirs, and the plugging agent is suitable for plugging construction of ultra-deep fractured-vuggy oil reservoirs.

Description

Technical Field

[0001] This invention belongs to the field of reservoir plugging technology, and particularly relates to a composite resin plugging composition, its preparation method and application. Background Technology

[0002] Fractured-vuggy reservoirs are a special type of reservoir characterized by giant or large caverns and large fractures as the main storage spaces. Compared with sandstone reservoirs, they exhibit strong heterogeneity, anisotropy, and multi-scale characteristics. While domestic and international experts and scholars have conducted extensive research on leakage in porous and fractured reservoirs, systematic studies on leakage in fractured-vuggy reservoirs have not yet been carried out.

[0003] Chinese patent application CN116536035A discloses a method for preparing a controllable curing resin plugging system suitable for formations with severe well leakage. The system uses urea-formaldehyde resin, phenolic resin, and unsaturated polyester resin to form a resin matrix, and combines it with curing agents, solubilizers, catalysts, etc. to form a controllable curing resin plugging system. It can be controlled under high temperature and high pressure, and can provide long-term stable sealing. It has a wide range of applicable crack sizes. However, the curing of the resin under ultra-high temperature conditions is difficult to control, and safe construction conditions cannot be guaranteed.

[0004] Chinese patent application CN117567997A discloses a high-temperature resistant oil-based drilling fluid consolidation and plugging material for oil drilling. The plugging agent is prepared from water-insoluble and oil-insoluble resin, acid-soluble material, wetting agent, density regulator and fiber material. It can enter the leakage gap under the carry of oil-based drilling fluid to form a filter plug. At the same time, under the action of leakage pressure difference, it is bonded and consolidated into a high-strength integral structure. It has high stability and good plugging effect, but it can only meet the plugging requirements under high temperature conditions of 150℃.

[0005] The literature "Application of Thermosetting Resin Plugging Grout System in Changqing Oilfield" reports a thermosetting resin plugging grout system established using nonionic epoxy resin, organic amine thermosetting agents, bridging plugging materials, and suspension thickeners as raw materials. This system exhibits good suspension properties, strong retention of leaked layers, high curing strength of the plugging grout, and low construction risk. However, the resin plugging grout shows poor stability under high-temperature conditions, making long-term effective sealing impossible.

[0006] The literature "Development and Evaluation of High-Strength Curable Resin Plugging Agent PMMM" reports a resin plugging slurry developed using hexamethoxymethyl melamine resin and a potential curing agent as raw materials. The formulation is simple, the curing is controllable, and the strength is high. It has certain application prospects in severe well leakage in fractured formations. However, its temperature resistance is poor, which limits its application in high-temperature formations.

[0007] As oil and gas exploration and development gradually expands into deeper formations, conventional plugging agents are no longer sufficient to meet the needs of plugging leaks in complex oil reservoirs. There is an urgent need to develop plugging materials that can withstand ultra-high temperatures, possess high strength, and maintain long-term stability. However, single curable resins cannot simultaneously possess the excellent properties of high strength and ultra-high temperature resistance, making it difficult to meet the plugging requirements of ultra-deep fractured-vuggy reservoirs. Furthermore, to ensure construction safety at the plugging site, curable resin plugging materials must also have a controllable curing time. Therefore, it is necessary to develop a composite resin plugging system suitable for fractured-vuggy reservoirs that is resistant to ultra-high temperatures, has high pressure resistance, and allows for controllable curing. Summary of the Invention

[0008] To address the challenges of achieving high strength, ultra-high temperature resistance, and controllable curing time simultaneously in existing curable resin plugging materials, this invention aims to provide a composite resin plugging composition, its preparation method, and its applications. The composite resin plugging composition exhibits high strength, can withstand temperatures up to 240°C, and has a controllable curing time, overcoming the shortcomings of existing curable resin plugging materials and meeting the plugging requirements for fractured-vuggy reservoirs.

[0009] To achieve the above objectives, one aspect of the present invention provides a composite resin sealing composition, the raw materials of which include a composite sealing agent, a latent curing agent, a flow pattern modifier, a first crosslinking agent, a retarder, a filler, and water;

[0010] The composite sealant comprises waterborne epoxy resin, amino-terminated polyether, polyimide resin, melamine-formaldehyde resin, a second crosslinking agent, and a polymer. Specifically, by weight, the waterborne epoxy resin comprises 10-30 parts epoxy resin, 0.3-0.8 parts amino-terminated polyether, 10-20 parts polyimide resin, 5-15 parts melamine-formaldehyde resin, 0.8-0.2 parts the second crosslinking agent, and 0.3-0.8 parts the polymer.

[0011] The polymer is a copolymer of acrylamide, acrylic acid, N-vinylpyrrolidone and methacryloyloxyethyl dimethyl benzyl ammonium halide or a copolymer of acrylamide, acrylic acid, N-vinylpyrrolidone and methacryloyloxyethyl dimethyl alkyl ammonium halide.

[0012] According to a specific embodiment of the present invention, the total mass of the raw materials of the composite resin sealing composition is 100%, and the raw materials of the composite resin sealing composition include 20-50 wt% of the composite sealing agent, 0.5-5.0 wt% of the latent curing agent, 0.05-3.0 wt% of the flow modifier, 0.05-2.0 wt% of the first crosslinking agent, 0.5-1.5 wt% of the retarder, 3-10 wt% of the filler, and the balance being water.

[0013] According to one specific embodiment of the present invention, the second crosslinking agent is a mixture of diethylenetriamine and hydroxypropyl methacrylate.

[0014] According to a specific embodiment of the present invention, in the second crosslinking agent, the mass ratio of diethylenetriamine to hydroxypropyl methacrylate is (2-4):(1-3); and / or

[0015] In the polymer, the molar ratio of acrylamide, acrylic acid, N-vinylpyrrolidone and methacryloyloxyethyl dimethyl benzyl ammonium halide or the molar ratio of acrylamide, acrylic acid, N-vinylpyrrolidone and methacryloyloxyethyl dimethyl alkyl ammonium halide is (4-2):(3-2):(2-1):(2-1);

[0016] Preferably, the polymer has a molecular weight of 15,000.

[0017] According to a specific embodiment of the present invention, the composite sealing agent is prepared in the following manner:

[0018] The aqueous epoxy resin and the amino-terminated polyether are subjected to a first reaction in water to obtain an amino-terminated polyether modified epoxy resin.

[0019] The amino-terminated polyether modified epoxy resin, polyimide resin, and melamine-formaldehyde resin are mixed to obtain a resin mixture;

[0020] The second crosslinking agent, polymer, and resin mixture are mixed, dried, and pulverized to obtain the composite resin sealant.

[0021] According to one specific embodiment of the present invention, the temperature of the first reaction is 70-90°C; and / or the duration is 0.5-5h.

[0022] According to one specific embodiment of the present invention, the latent curing agent is a diphenyl biguanide compound and / or dicyandiamide.

[0023] According to a specific embodiment of the present invention, the raw materials of the diphenylbiguanide compound include, by weight: 20-30 parts sodium dicyandiamide, 10-20 parts diaminodiphenyl sulfone and 5-15 parts 4,4'-diaminodiphenylmethane.

[0024] According to a specific embodiment of the present invention, the diphenylbiguanide compound is prepared according to the following steps:

[0025] The sodium dicyandiamide, diaminodiphenyl sulfone, and 4,4'-diaminodiphenylmethane were subjected to a second reaction in an alcohol solvent, and the pH was adjusted to acidic to obtain a reaction product solution.

[0026] The alcohol solvent in the reaction product solution is removed, and the product is washed and dried to obtain the diphenylbiguanide compound.

[0027] According to one specific embodiment of the present invention, the second reaction is carried out in an inert gas atmosphere; and / or

[0028] The second reaction temperature is 70-90℃; and / or the duration is 1-2 hours; and / or

[0029] The acidity refers to a pH of 4-5.

[0030] According to one specific embodiment of the present invention, the flow pattern regulator is a weak gel flow pattern regulator and / or nanocellulose;

[0031] The raw materials of the weak gel flow modifier include, by weight: 10-20 parts xanthan gum, 20-30 parts acrylic acid, 20-30 parts 2-acrylamide-2-methylpropanesulfonic acid, 5-15 parts N-vinylpyrrolidone, 2-4 parts organoboron crosslinking agent and 1-2 parts initiator.

[0032] Preferably, the initiator is a mixture of potassium persulfate and dimethyl azobisisobutyrate;

[0033] Preferably, the mass ratio of potassium persulfate to dimethyl azobisisobutyrate is (1-3):(2-4).

[0034] According to a specific embodiment of the present invention, the weak gel flow pattern regulator is prepared according to the following steps:

[0035] The xanthan gum, acrylic acid, 2-acrylamide-2-methylpropanesulfonic acid, N-vinylpyrrolidone and organoboron crosslinking agent are mixed in water, the pH is adjusted to neutral, and a third reaction is carried out under the action of an initiator. The mixture is then washed, dried and pulverized to obtain the weak gel flow modifier.

[0036] According to one specific embodiment of the present invention, the third reaction is carried out in an inert gas atmosphere; and / or

[0037] The temperature of the third reaction is 60-80℃; and / or the duration is 10-20 min.

[0038] According to one specific embodiment of the present invention, the first crosslinking agent is a mixture of trimethylolethane and propylenediamine; and / or

[0039] The retarder is at least one of hydroxyethylidene diphosphonic acid, sodium lignosulfonate and aminotrimethylene phosphonic acid;

[0040] And / or the filler is a mixture of quartz sand and hydrophilic nano silica.

[0041] According to a specific embodiment of the present invention, in the first crosslinking agent, the mass ratio of trimethylolethane to propylenediamine is 1:(1-3); and / or

[0042] The retarder is a mixture of hydroxyethylidene diphosphonic acid and sodium lignosulfonate in a mass ratio of 1:1; and / or

[0043] In the filler, the mass ratio of the quartz sand to the hydrophilic nano silica is (3-5):(1-2).

[0044] According to a specific embodiment of the present invention, the particle size of the composite sealing agent is 1-3 mm; and / or

[0045] The flow pattern regulator has a particle size of 1-1.5 mm; and / or

[0046] The hydrophilic nano-silica has a particle size of 20-100 nm.

[0047] The second invention provides a method for preparing a composite resin plugging composition as described in the first invention, comprising the following steps:

[0048] The composite sealant is dispersed in water, mixed with the crosslinking agent, and then the latent curing agent, retarder, flow modifier and filler are added to obtain the composite resin sealant composition.

[0049] The third aspect of this invention provides the application of the composite resin plugging composition according to the first aspect of this invention or the composite resin plugging composition prepared by the method described in the second aspect of this invention in reservoir plugging;

[0050] Preferably, the application temperature is 160-240℃.

[0051] The beneficial effects of this invention are:

[0052] To address the limitations of existing curable resin sealing materials in simultaneously achieving high strength, ultra-high temperature resistance, and controllable curing time, this invention aims to provide a composite resin sealing composition, its preparation method, and its applications. Compared with existing technologies, this invention offers at least the following advantages:

[0053] 1. The composite resin sealing composition provided by the present invention contains the composite sealing agent, which is a composite of three thermosetting resins: waterborne epoxy resin, polyimide resin and melamine-formaldehyde resin. It also has good temperature resistance and mechanical properties, which is beneficial to improving the compressive strength of the composite resin sealing composition after curing at the optimal high temperature curing time and its pressure-bearing sealing ability for cracks.

[0054] 2. The latent curing agent, preferably a diphenyl biguanide compound, added to the composite resin sealing composition provided by the present invention has good latent characteristics and can delay the curing of the composite resin sealing composition; the biguanide group, flexible bond, and benzene ring rigid group in the structure of the diphenyl biguanide compound make it compatible with the epoxy resin in the composite resin sealing composition, and at the same time improve the compressive strength and sealing stability of the composite resin sealing composition after curing at the optimal high temperature curing time.

[0055] 3. Based on the use of diphenyl biguanide compounds as latent curing agents to delay curing time, the present invention further adds a retarder with a specific formulation to the composite resin plugging composition, which can further extend the curing time of the composite resin plugging composition; and, the curing time of the composite resin plugging composition can be flexibly adjusted mainly by adjusting the type and amount of latent curing agent and retarder, so as to meet the requirements of safe construction on the plugging site.

[0056] 4. The composite resin plugging composition provided by the present invention also contains fillers preferably made of quartz sand and hydrophilic nano-silica. When these two fillers are added to the composite resin plugging composition, they can fill and seal large leakage channels such as pores and caverns in fractured reservoirs when the composite resin plugging composition is not cured and has fluidity. By bridging and stacking to form a relatively dense sealing layer, the pressure-bearing sealing ability of the composite resin plugging composition against fractures is synergistically improved.

[0057] 5. The composite resin plugging composition provided by the present invention preferably also contains a weak gel flow modifier. The weak gel flow modifier is formulated to effectively control the rheological properties of the composite resin plugging composition, thereby increasing the uniformity of the filler dispersion in the composite resin plugging composition. This is beneficial for forming a uniform and stable seal at various points on the crack area, and avoids repeated leakage due to the decrease in the density of the local sealing layer caused by uneven filler dispersion, which reduces the sealing strength.

[0058] 6. The composite resin sealing composition can be prepared and used on-site. Its preparation and application methods are simple. Before curing, it has sufficient fluidity for easy handling, and the curing time is adjustable, maintaining fluidity until curing at formation temperature, effectively sealing cracks. Experiments have shown that the composite resin sealing compositions within the scope of this invention all possess the above-mentioned technical effects. Any changes, including but not limited to the type and amount of raw materials, will negatively impact the sealing performance of the composite resin sealing composition. Detailed Implementation

[0059] The present invention will be further described below with reference to the embodiments. However, the embodiments of the present invention are merely illustrative examples and should not be construed as limiting the present invention under any circumstances.

[0060] The first aspect of the present invention provides a composite resin sealing composition, the raw materials of which include a composite sealing agent, a latent curing agent, a flow pattern regulator, a first crosslinking agent, a retarder, a filler and water;

[0061] The composite sealant comprises waterborne epoxy resin, amino-terminated polyether, polyimide resin, melamine-formaldehyde resin, a second crosslinking agent, and a polymer. Specifically, by weight, the waterborne epoxy resin comprises 10-30 parts epoxy resin, 0.3-0.8 parts amino-terminated polyether, 10-20 parts polyimide resin, 5-15 parts melamine-formaldehyde resin, 0.8-0.2 parts the second crosslinking agent, and 0.3-0.8 parts the polymer.

[0062] The polymer is a copolymer of acrylamide, acrylic acid, N-vinylpyrrolidone and methacryloyloxyethyl dimethyl benzyl ammonium halide or a copolymer of acrylamide, acrylic acid, N-vinylpyrrolidone and methacryloyloxyethyl dimethyl alkyl ammonium halide.

[0063] In one embodiment of the present invention, the total mass of the raw materials of the composite resin sealing composition is 100%, and the raw materials of the composite resin sealing composition include 20-50 wt% of the composite sealing agent, 0.5-5.0 wt% of the latent curing agent, 0.05-3.0 wt% of the flow modifier, 0.05-2.0 wt% of the first crosslinking agent, 0.5-1.5 wt% of the retarder, 3-10 wt% of the filler and the balance being water.

[0064] In a preferred embodiment of the present invention, the total mass of the raw materials of the composite resin sealing composition is 100%, and the raw materials of the composite resin sealing composition include 30-40 wt% of the composite sealing agent, 1.0-3.0 wt% of the latent curing agent, 1.0-2.0 wt% of the flow modifier, 0.5-1.5 wt% of the first crosslinking agent, 0.8-1.2 wt% of the retarder, 4-7 wt% of the filler and the balance being water.

[0065] In a preferred embodiment of the present invention, the composite sealing agent comprises, by weight, 20 parts of epoxy resin, 0.5 parts of amino-terminated polyether, 15 parts of polyimide resin, 10 parts of melamine-formaldehyde resin, 1.0 part of the second crosslinking agent, and 0.5 parts of polymer.

[0066] In one embodiment of the present invention, both the polyimide resin and the melamine-formaldehyde resin are water-soluble resins.

[0067] In one embodiment of the present invention, the molecular weight of the terminal amino polyether is 2000.

[0068] In one embodiment of the present invention, the second crosslinking agent is a mixture of diethylenetriamine and hydroxypropyl methacrylate.

[0069] In one embodiment of the present invention, the mass ratio of diethylenetriamine to hydroxypropyl methacrylate in the second crosslinking agent is (2-4):(1-3).

[0070] In a preferred embodiment of the present invention, the mass ratio of diethylenetriamine to hydroxypropyl methacrylate in the second crosslinking agent is 3:2.

[0071] In one embodiment of the present invention, the molar ratio of acrylamide, acrylic acid, N-vinylpyrrolidone and methacryloyloxyethyl dimethyl benzyl ammonium halide in the polymer or the molar ratio of acrylamide, acrylic acid, N-vinylpyrrolidone and methacryloyloxyethyl dimethyl alkyl ammonium halide is (4-2):(3-2):(2-1):(2-1).

[0072] In one embodiment of the present invention, the polymer is a copolymer of acrylamide, acrylic acid, N-vinylpyrrolidone and methacryloyloxyethyl dimethylalkylammonium bromide;

[0073] Preferably, in the polymer, the molar ratio of acrylamide, acrylic acid, N-vinylpyrrolidone and methacryloyloxyethyl dimethylalkylammonium bromide is 4:3:1:1; and the molecular weight is 15000.

[0074] In one embodiment of the present invention, the composite sealant is prepared as follows:

[0075] The aqueous epoxy resin and the amino-terminated polyether are subjected to a first reaction in water to obtain an amino-terminated polyether modified epoxy resin.

[0076] The amino-terminated polyether modified epoxy resin, polyimide resin, and melamine-formaldehyde resin are mixed to obtain a resin mixture;

[0077] The second crosslinking agent, polymer, and resin mixture are mixed, dried, and pulverized to obtain the composite resin sealant.

[0078] In a preferred embodiment of the present invention, the aqueous epoxy resin and water are first mixed and heated to the temperature required for the first reaction, and then the terminal amino polyether is added to carry out the first reaction.

[0079] In one embodiment of the present invention, the amount of water used is at least sufficient to dissolve the aqueous epoxy resin and the amino-terminated polyether;

[0080] Preferably, the mass ratio of the waterborne epoxy resin to water is 1:(5-7);

[0081] More preferably, the mass ratio of the waterborne epoxy resin to water is 1:6.

[0082] In one embodiment of the present invention, the temperature of the first reaction is 70-90°C; and / or the duration is 0.5-5h.

[0083] In a preferred embodiment of the present invention, the temperature of the first reaction is 80°C; and / or the duration is 1 hour.

[0084] In one embodiment of the present invention, the particle size of the composite resin sealant is 1-3 mm.

[0085] In one embodiment of the present invention, the latent curing agent is selected from at least one of dicyandiamide, oxalic acid dihydrazide, sulfamic acid sulfone, diphenyl biguanide compounds, 2-phenylimidazole, and trimellitic dianhydride.

[0086] In a preferred embodiment of the present invention, the latent curing agent is the diphenylbiguanide compound and / or dicyandiamide.

[0087] In a more preferred embodiment of the present invention, the latent curing agent is the diphenylbiguanide compound.

[0088] In one embodiment of the present invention, the raw materials of the diphenylbiguanide compound include, by weight: 20-30 parts sodium dicyandiamide, 10-20 parts diaminodiphenyl sulfone and 5-15 parts 4,4'-diaminodiphenylmethane.

[0089] In a preferred embodiment of the present invention, the raw materials of the diphenylbiguanide compound include, by weight: 25 parts sodium dicyandiamide, 15 parts diaminodiphenyl sulfone, and 10 parts 4,4'-diaminodiphenylmethane.

[0090] In one embodiment of the present invention, the diphenylbiguanide compound is prepared according to the following steps:

[0091] The sodium dicyandiamide, diaminodiphenyl sulfone, and 4,4'-diaminodiphenylmethane were subjected to a second reaction in an alcohol solvent, and the pH was adjusted to acidic to obtain a reaction product solution.

[0092] The alcohol solvent in the reaction product solution is removed, and the product is washed and dried to obtain the diphenylbiguanide compound.

[0093] In a preferred embodiment of the present invention, sodium dicyandiamide, diaminodiphenyl sulfone and 4,4'-diaminodiphenylmethane are first dissolved in the alcohol solvent to obtain sodium dicyandiamide alcohol solution, diaminodiphenyl sulfone alcohol solution and 4,4'-diaminodiphenylmethane alcohol solution.

[0094] Then, in an inert gas atmosphere, the diaminodiphenylsulfone alcohol solution and the 4,4'-diaminodiphenylmethane alcohol solution are simultaneously added dropwise to the sodium dicyandiamide alcohol solution to carry out the second reaction.

[0095] In one embodiment of the present invention, the amount of alcohol solvent used in the sodium dicyandiamide alcohol solution is sufficient to dissolve the sodium dicyandiamide;

[0096] Preferably, in the sodium dicyandiamide alcohol solution, the mass-to-volume ratio of sodium dicyandiamide to alcohol solvent is (0.1-0.2) g / mL, more preferably 0.1 g / mL.

[0097] In one embodiment of the present invention, in the diaminodiphenyl sulfone alcohol solution, the amount of alcohol solvent used is sufficient to dissolve the diaminodiphenyl sulfone;

[0098] Preferably, in the diaminodiphenyl sulfone alcohol solution, the mass-to-volume ratio of diaminodiphenyl sulfone to alcohol solvent is (0.2-0.3) g / mL, more preferably 0.2 g / mL.

[0099] In one embodiment of the present invention, the amount of alcohol solvent used in the 4,4'-diaminodiphenylmethane alcohol solution is sufficient to dissolve the 4,4'-diaminodiphenylmethane.

[0100] Preferably, in the 4,4'-diaminodiphenylmethane alcohol solution, the mass-to-volume ratio of 4,4'-diaminodiphenylmethane to the alcohol solvent is (0.15-0.2) g / mL, more preferably 0.2 g / mL.

[0101] In one embodiment of the present invention, the alcohol solvent is a lower alcohol, such as methanol.

[0102] In one embodiment of the invention, the second reaction is carried out in an inert gas atmosphere.

[0103] In one embodiment of the present invention, the second reaction temperature is 70-90°C; and / or the duration is 1-2 hours.

[0104] In a preferred embodiment of the present invention, the second reaction temperature is 90°C; and / or the reaction time is 2 hours.

[0105] In one embodiment of the present invention, the acidity refers to a pH of 4-5.

[0106] In a preferred embodiment of the present invention, after the second reaction is completed, hydrochloric acid aqueous solution is added to adjust the pH.

[0107] In a preferred embodiment of the present invention, the concentration of the hydrochloric acid aqueous solution is 20-38 wt%.

[0108] In one embodiment of the present invention, the flow pattern regulator is selected from at least one of nanocellulose, organic-inorganic composite weak gel, modified fatty acid, modified water-soluble ternary associative polymer PASM-t, and weak gel flow pattern regulator.

[0109] In a preferred embodiment of the present invention, the flow pattern regulator is the weak gel flow pattern regulator and / or nanocellulose.

[0110] In a more preferred embodiment of the present invention, the flow pattern regulator is the weak gel flow pattern regulator.

[0111] In a preferred embodiment of the present invention, the raw materials of the weak gel flow modifier include, by weight: 10-20 parts xanthan gum, 20-30 parts acrylic acid, 20-30 parts 2-acrylamide-2-methylpropanesulfonic acid, 5-15 parts N-vinylpyrrolidone, 2-4 parts organoboron crosslinking agent and 1-2 parts initiator.

[0112] In a preferred embodiment of the present invention, the raw materials of the weak gel flow modifier include, by weight: 15 parts xanthan gum, 25 parts acrylic acid, 25 parts 2-acrylamide-2-methylpropanesulfonic acid, 10 parts N-vinylpyrrolidone, 3 parts organoboron crosslinking agent and 1.5 parts initiator.

[0113] In a preferred embodiment of the present invention, the initiator is a mixture of potassium persulfate and dimethyl azobisisobutyrate.

[0114] In a preferred embodiment of the present invention, the mass ratio of potassium persulfate to dimethyl azobisisobutyrate is (1-3):(2-4).

[0115] In a preferred embodiment of the present invention, the mass ratio of potassium persulfate to dimethyl azobisisobutyrate is 2:3.

[0116] In one embodiment of the present invention, the weak gel flow modifier is prepared according to the following steps:

[0117] The xanthan gum, acrylic acid, 2-acrylamide-2-methylpropanesulfonic acid, N-vinylpyrrolidone and organoboron crosslinking agent are mixed in water, the pH is adjusted to neutral, and a third reaction is carried out under the action of an initiator. The mixture is then washed, dried and pulverized to obtain the weak gel flow modifier.

[0118] In a preferred embodiment of the present invention, the xanthan gum is first dissolved in water, and then the acrylic acid, 2-acrylamide-2-methylpropanesulfonic acid, N-vinylpyrrolidone and organoboron crosslinking agent are added sequentially in an inert gas atmosphere.

[0119] In one embodiment of the invention, the amount of water used is at least sufficient to dissolve the xanthan gum;

[0120] Preferably, the mass ratio of xanthan gum to water is 1:(150-300), more preferably 1:200.

[0121] In a preferred embodiment of the present invention, an inorganic strong base is added to adjust the pH to neutral.

[0122] In a preferred embodiment of the present invention, the inorganic strong base is a mixture of sodium hydroxide and potassium hydroxide.

[0123] In a preferred embodiment of the present invention, sodium hydroxide and potassium hydroxide are mixed in equal mass in the inorganic strong base.

[0124] In one embodiment of the invention, the third reaction is carried out in an inert gas atmosphere.

[0125] In one embodiment of the present invention, the temperature of the third reaction is 60-80°C; and / or the duration is 10-20 min.

[0126] In a preferred embodiment of the present invention, the temperature of the third reaction is 70°C; and / or the duration is 15 min.

[0127] In one embodiment of the present invention, the particle size of the flow pattern regulator is 1-1.5 mm.

[0128] The inert gas atmosphere referred to in this invention is preferably a nitrogen atmosphere, a helium atmosphere, or an argon atmosphere.

[0129] In one embodiment of the present invention, the first crosslinking agent is selected from at least one of styrene, p-toluenesulfonic acid, trimethylolethane, divinylbenzene, diethylenetriamine, trimethoxysilane, and propylenediamine.

[0130] In a preferred embodiment of the present invention, the first crosslinking agent is a mixture of trimethylolethane and propylenediamine.

[0131] In a preferred embodiment of the present invention, the mass ratio of trimethylolethane to propylenediamine in the first crosslinking agent is 1:(1-3), more preferably 1:2.

[0132] In one embodiment of the present invention, the retarder is selected from at least one of hydroxyethylidene diphosphonic acid, aminotrimethylene phosphonic acid, sodium gluconate, sodium hexametaphosphate, citric acid, and sodium lignosulfonate.

[0133] In a preferred embodiment of the present invention, the retarder is at least one of hydroxyethylidene diphosphonic acid, sodium lignosulfonate, and aminotrimethylene phosphonic acid.

[0134] In a more preferred embodiment of the present invention, the retarder is a mixture of hydroxyethylidene diphosphonic acid and sodium lignosulfonate.

[0135] In a preferred embodiment of the present invention, the retarder contains an equal mass mixture of hydroxyethylidene diphosphonic acid and sodium lignosulfonate.

[0136] In one embodiment of the present invention, the filler is selected from at least one of quartz sand, walnut shell, calcium carbonate, fiber, mica flakes and hydrophilic nano silica.

[0137] In a preferred embodiment of the present invention, the filler is a mixture of quartz sand and hydrophilic nano-silica.

[0138] In a preferred embodiment of the present invention, the mass ratio of the quartz sand and the hydrophilic nano-silica in the filler is (3-5):(1-2).

[0139] In a preferred embodiment of the present invention, the hydrophilic nano-silica has a particle size of 20-100 nm.

[0140] In a preferred embodiment of the present invention, the quartz sand has a particle size of 70-150 μm and an average particle size of 100 μm.

[0141] A second aspect of the present invention provides a method for preparing a composite resin plugging composition as described in any one of the present invention, comprising the following steps:

[0142] The composite sealant is dispersed in water, mixed with the crosslinking agent, and then the latent curing agent, retarder, flow modifier and filler are added to obtain the composite resin sealant composition.

[0143] The third aspect of the present invention provides the application of the composite resin plugging composition according to the first aspect of the present invention or the composite resin plugging composition prepared by the method according to the second aspect of the present invention in reservoir plugging.

[0144] In a preferred embodiment of the present invention, the application includes: preparing the composite resin plugging composition on-site and injecting it into the target formation; under the action of the formation temperature, the composite resin plugging composition undergoes a curing reaction to seal the cracks in the formation.

[0145] In a preferred embodiment of the invention, the temperature of the application is 160-240°C.

[0146] The following provides examples of the preparation of the composite resin plugging composition, along with corresponding test examples, to provide a detailed description of the technical solution of the present invention.

[0147] The following is some information about the raw materials used:

[0148] Waterborne epoxy resin: Nonionic waterborne epoxy resin purchased from Shanghai Huayi Fine Chemical Co., Ltd.

[0149] Amino-terminated polyether: molecular weight 2000, purchased from Haian Petrochemical Plant, Jiangsu Province, model MPEG-1300;

[0150] Polyimide resin: purchased from Guangdong Dongdun New Material Technology Co., Ltd., model SEAPUR 55X10;

[0151] Melamine-formaldehyde resin: purchased from Merck, model number MFCD00197912;

[0152] Polymer: FPAM copolymer with a molecular weight of 15,000, obtained by copolymerization of acrylamide, acrylic acid, N-vinylpyrrolidone and methacryloyloxyethyl dimethylalkylammonium bromide in a molar ratio of 4:3:1:1, purchased from Beijing Conojet Co., Ltd.

[0153] Organic boron crosslinking agent: purchased from Shandong Bosheng Chemical Co., Ltd.;

[0154] Hydrophilic nano-silica: purchased from Nanjing Baoket New Materials Co., Ltd., model PST-H20, particle size 20nm;

[0155] Quartz sand: particle size 70-150μm, average particle size 100μm, purchased from Lingshou County Huixin Mining Processing Plant;

[0156] Nanocellulose: Purchased from Hubei Darli Chemical Co., Ltd.

[0157] Unless otherwise specified, all other ingredients listed below are commercially available.

[0158] The room temperature referred to in this invention refers to 25°C.

[0159] Preparation of composite sealing agent

[0160] Preparation Example 1

[0161] Prepare the composite sealing agent according to the following steps:

[0162] (1) Add waterborne epoxy resin containing 20g epoxy resin to a three-necked flask equipped with a stirrer and thermometer, add 120g deionized water, heat the system to 80℃, add 0.5g terminal amino polyether, react at constant temperature for 1h, and then cool to room temperature to obtain terminal amino polyether modified epoxy resin.

[0163] (2) Add 15g of polyimide resin and 10g of melamine-formaldehyde resin to the obtained amino-terminated polyether modified epoxy resin in sequence, mix thoroughly and evenly to obtain a resin mixture.

[0164] (3) Add 0.6g diethylenetriamine, 0.4g hydroxypropyl methacrylate and 0.5g polymer to the resin mixture, mix and disperse evenly, and then dry and pulverize to obtain a composite sealant with a particle size of 1-3mm.

[0165] Comparative Preparation Example 1

[0166] The polyimide resin in Preparation Example 1 was removed, and everything else was the same as in Preparation Example 1, to prepare a composite sealant with a particle size of 1-3 mm.

[0167] Comparative Preparation Example 2

[0168] The melamine-formaldehyde resin in Preparation Example 1 was removed, and everything else was the same as in Preparation Example 1, to prepare a composite sealant with a particle size of 1-3 mm.

[0169] Comparative preparation example 3

[0170] The polymer in Preparation Example 1 was removed, and everything else was the same as in Preparation Example 1, to prepare a composite plugging agent with a particle size of 1-3 mm.

[0171] Comparative preparation example 4

[0172] Remove the amino-terminated polyether from Preparation Example 1 and prepare the composite sealant according to the following steps:

[0173] (1) Add 20g of waterborne epoxy resin to 120g of deionized water and mix thoroughly to disperse evenly; add 15g of polyimide resin and 10g of melamine-formaldehyde resin in sequence and mix thoroughly to obtain waterborne epoxy resin aqueous solution.

[0174] (2) Add 0.6g diethylenetriamine, 0.4g hydroxypropyl methacrylate and 0.5g polymer to the aqueous epoxy resin solution, mix and disperse thoroughly, and then dry and pulverize to obtain a composite sealant with a particle size of 1-3mm.

[0175] Preparation of diphenylbiguanide compounds

[0176] Preparation Example 2

[0177] Diphenylbiguanide compounds were prepared according to the following steps:

[0178] (1) Add 25g of sodium dicyandiamide to a four-necked flask equipped with a constant pressure dropping funnel, a stirrer and a thermometer, and then add 250mL of methanol to obtain a methanol solution of sodium dicyandiamide.

[0179] (2) Under helium protection and stirring conditions, 50 mL of 0.2 g / mL methanol solution of 4,4'-diaminodiphenylmethane and 75 mL of 0.2 g / mL methanol solution of diaminodiphenyl sulfone were added dropwise from the constant pressure dropping funnel into the three-necked flask.

[0180] (3) After the droplet was finished, the reaction was carried out at 90°C for 2 hours under helium protection and stirring. The pH of the reaction system was adjusted to 4-5 using a 38% hydrochloric acid aqueous solution. Then, after removing methanol, washing and drying, diphenyl biguanide compounds were obtained.

[0181] Comparative preparation example 5

[0182] The diaminodiphenyl sulfone from Preparation Example 2 was removed, and diphenylbiguanide compounds were prepared according to the following steps:

[0183] (1) Add 25g of sodium dicyandiamide to a four-necked flask equipped with a constant pressure dropping funnel, a stirrer and a thermometer, and then add 250mL of methanol to obtain a methanol solution of sodium dicyandiamide.

[0184] (2) Under helium protection and stirring conditions, 50 mL of 0.2 g / mL methanol solution of 4,4'-diaminodiphenylmethane and 75 mL of methanol were added dropwise from the constant pressure dropping funnel into the three-necked flask.

[0185] (3) After the droplet was finished, the reaction was carried out at 90°C for 2 hours under helium protection and stirring. The pH of the reaction system was adjusted to 4-5 using a 38% hydrochloric acid aqueous solution. Then, after removing methanol, washing and drying, diphenyl biguanide compounds were obtained.

[0186] Comparative preparation example 6

[0187] Remove the 4,4'-diaminodiphenylmethane from Preparation Example 2 and prepare diphenylbiguanide compounds according to the following steps:

[0188] (1) Add 25g of sodium dicyandiamide to a four-necked flask equipped with a constant pressure dropping funnel, a stirrer and a thermometer, and then add 250mL of methanol to obtain a methanol solution of sodium dicyandiamide.

[0189] (2) Under helium protection and stirring conditions, 50 mL of methanol and 75 mL of the prepared methanol solution with a mass concentration of 0.2 g / mL diaminodiphenyl sulfone were simultaneously added dropwise from the constant pressure dropping funnel into the three-necked flask.

[0190] (3) After the droplet was finished, the reaction was carried out at 90°C for 2 hours under helium protection and stirring. The pH of the reaction system was adjusted to 4-5 using a 38% hydrochloric acid aqueous solution. Then, after removing methanol, washing and drying, diphenyl biguanide compounds were obtained.

[0191] Comparative preparation example 7

[0192] Remove sodium dicyandiamide from Preparation Example 2 and prepare diphenylbiguanide compounds according to the following steps:

[0193] (1) Add 250 mL of methanol to a four-necked flask equipped with a constant pressure dropping funnel, a stirrer and a thermometer;

[0194] (2) Under helium protection and stirring conditions, 50 mL of 0.2 g / mL methanol solution of 4,4'-diaminodiphenylmethane and 75 mL of 0.2 g / mL methanol solution of diaminodiphenyl sulfone were added dropwise from the constant pressure dropping funnel into the three-necked flask.

[0195] (3) After the droplet was finished, the reaction was carried out at 90°C for 2 hours under helium protection and stirring. The pH of the reaction system was adjusted to 4-5 using a 38% hydrochloric acid aqueous solution. Then, after removing methanol, washing and drying, diphenyl biguanide compounds were obtained.

[0196] Preparation of weak gel flow modifier

[0197] Preparation Example 3

[0198] The weak gel flow modifier was prepared according to the following steps:

[0199] (1) Add 15g xanthan gum to a four-necked flask equipped with a stirrer, a cold water reflux device and a thermometer, add 3000g deionized water to dissolve it, and obtain a xanthan gum aqueous solution; introduce nitrogen gas into the flask;

[0200] (2) Add 25g of acrylic acid, 25g of 2-acrylamide-2-methylpropanesulfonic acid, 10g of N-vinylpyrrolidone and 3g of organoboron crosslinking agent to xanthan gum aqueous solution in sequence and mix thoroughly. Adjust the pH value to neutral using an alkaline regulator (sodium hydroxide and potassium hydroxide mixed in a mass ratio of 1:1), heat to 70℃, add 0.6g of potassium persulfate and 0.9g of dimethyl azobisisobutyrate, and stir at a constant temperature for 15 minutes. Then wash, dry, pulverize and sieve to obtain a weak gel flow modulator with a particle size of 1-1.5mm.

[0201] Comparative Preparation Example 8

[0202] Remove the xanthan gum from Preparation Example 3 and prepare the weak gel flow modifier according to the following steps:

[0203] (1) Add 3000g of deionized water to a four-necked flask equipped with a stirrer, a cold water reflux device and a thermometer; introduce nitrogen gas into the flask;

[0204] (2) Add 25g of acrylic acid, 25g of 2-acrylamide-2-methylpropanesulfonic acid, 10g of N-vinylpyrrolidone and 3g of organoboron crosslinking agent to deionized water in sequence and mix thoroughly. Adjust the pH value to neutral using an alkaline regulator (sodium hydroxide and potassium hydroxide mixed in a mass ratio of 1:1), heat to 70℃, add 0.6g of potassium persulfate and 0.9g of dimethyl azobisisobutyrate, and stir at a constant temperature for 15 minutes. Then wash, dry, pulverize and sieve to obtain a weak gel flow modulator with a particle size of 1-1.5mm.

[0205] Comparative preparation example 9

[0206] The N-vinylpyrrolidone in Preparation Example 3 was removed, and the rest was the same as in Preparation Example 3, to prepare a weak gel flow modifier with a particle size of 1-1.5 mm.

[0207] A composite resin sealing composition was prepared using the composite sealing agent, diphenyl biguanide compound, and weak gel flow modifier prepared above.

[0208] Unless otherwise specified, the following examples and some comparative examples use the composite sealant prepared in Preparation Example 1 and Preparation Example 2 (Example 1).

[0209] The raw material formulation of the composite resin sealing composition provided in this embodiment is as follows:

[0210] The total mass of the raw materials in the composite resin sealing composition is 100%. The raw materials of the composite resin sealing composition include 40 wt% of the composite sealing agent prepared in Preparation Example 1, 3 wt% of the diphenyl biguanide compound prepared in Preparation Example 2, 2 wt% of the weak gel flow modifier prepared in Preparation Example 3, 1.5 wt% of the first crosslinking agent, 1.2 wt% of the retarder, 7 wt% of the filler, and the balance being water.

[0211] The first crosslinking agent comprises trimethylolethane and propylenediamine in a mass ratio of 1:2; the retarder comprises hydroxyethylidene diphosphonic acid and sodium lignosulfonate in a mass ratio of 1:1; and the filler comprises quartz sand and hydrophilic nano silica in a mass ratio of 5:2.

[0212] According to the above formula, the composite resin sealing composition is prepared by the following steps:

[0213] (a) Weigh the composite plugging agent prepared in Preparation Example 1 and add it to a beaker. Add warm water at about 15°C, turn on the stirrer, and stir at a speed of 400 rpm until it is completely dissolved. Then add the first crosslinking agent and continue stirring for 10 minutes.

[0214] (b) Weigh the diphenyl biguanide compound prepared in Preparation Example 2, the retarder, the weak gel flow modifier prepared in Preparation Example 3, and the filler, mix them evenly in an empty beaker, increase the speed of the stirrer, and add the mixed powder to the mixture obtained in step (a) in small amounts several times. Stir thoroughly at a speed of 600 rpm to disperse the mortar evenly and form a liquid with a certain consistency to obtain the composite resin plugging composition S1.

[0215] Example 2

[0216] The raw material formulation of the composite resin sealing composition provided in this embodiment is as follows:

[0217] The total mass of the raw materials in the composite resin sealing composition is 100%. The raw materials of the composite resin sealing composition include 30 wt% of the composite sealing agent prepared in Preparation Example 1, 1 wt% of the diphenyl biguanide compound prepared in Preparation Example 2, 1 wt% of the weak gel flow modifier prepared in Preparation Example 3, 0.6 wt% of the first crosslinking agent, 0.8 wt% of the retarder, 4 wt% of the filler, and the balance being water.

[0218] The first crosslinking agent comprises trimethylol ethane and propylenediamine in a mass ratio of 1:2; the retarder comprises hydroxyethylidene diphosphonic acid and sodium lignosulfonate in a mass ratio of 1:1; and the filler comprises quartz sand and hydrophilic nano silica in a mass ratio of 3:1.

[0219] According to the above formula, the composite resin sealing composition S2 was prepared by following the same steps as in Example 1.

[0220] Example 3

[0221] The raw material formulation of the composite resin sealing composition provided in this embodiment is as follows:

[0222] The total mass of the raw materials in the composite resin sealing composition is 100%. The raw materials of the composite resin sealing composition include 40 wt% of the composite sealing agent prepared in Preparation Example 1, 3 wt% of the diphenyl biguanide compound prepared in Preparation Example 2, 1 wt% of the weak gel flow modifier prepared in Preparation Example 3, 1.5 wt% of the first crosslinking agent, 1.2 wt% of the retarder, 7 wt% of the filler, and the balance being water.

[0223] The first crosslinking agent comprises trimethylolethane and propylenediamine in a mass ratio of 1:2; the retarder comprises hydroxyethylidene diphosphonic acid and sodium lignosulfonate in a mass ratio of 1:1; and the filler comprises quartz sand and hydrophilic nano silica in a mass ratio of 5:2.

[0224] Following the above formulation, the composite resin sealing composition S3 was prepared using the same steps as in Example 1.

[0225] Example 4

[0226] The raw material formulation of the composite resin sealing composition provided in this embodiment is as follows:

[0227] The total mass of the raw materials in the composite resin sealing composition is 100%. The raw materials of the composite resin sealing composition include 40 wt% of the composite sealing agent prepared in Preparation Example 1, 3 wt% of the diphenyl biguanide compound prepared in Preparation Example 2, 2 wt% of the weak gel flow modifier prepared in Preparation Example 3, 0.6 wt% of the first crosslinking agent, 1.2 wt% of the retarder, 7 wt% of the filler, and the balance being water.

[0228] The first crosslinking agent comprises trimethylolethane and propylenediamine in a mass ratio of 1:2; the retarder comprises hydroxyethylidene diphosphonic acid and sodium lignosulfonate in a mass ratio of 1:1; and the filler comprises quartz sand and hydrophilic nano silica in a mass ratio of 5:2.

[0229] According to the above formulation, the composite resin sealing composition S4 was prepared by following the same steps as in Example 1.

[0230] Example 5

[0231] The raw material formulation of the composite resin sealing composition provided in this embodiment is as follows:

[0232] The total mass of the raw materials in the composite resin sealing composition is 100%. The raw materials of the composite resin sealing composition include 40 wt% of the composite sealing agent prepared in Preparation Example 1, 3 wt% of the diphenyl biguanide compound prepared in Preparation Example 2, 2 wt% of the weak gel flow modifier prepared in Preparation Example 3, 1.5 wt% of the first crosslinking agent, 0.8 wt% of the retarder, 7 wt% of the filler, and the balance being water.

[0233] The first crosslinking agent comprises trimethylolethane and propylenediamine in a mass ratio of 1:2; the retarder comprises hydroxyethylidene diphosphonic acid and sodium lignosulfonate in a mass ratio of 1:1; and the filler comprises quartz sand and hydrophilic nano silica in a mass ratio of 5:2.

[0234] According to the above formulation, the composite resin sealing composition S5 was prepared by following the same steps as in Example 1.

[0235] Example 6

[0236] The raw material formulation of the composite resin sealing composition provided in this embodiment is as follows:

[0237] The total mass of the raw materials in the composite resin sealing composition is 100%. The raw materials of the composite resin sealing composition include 40 wt% of the composite sealing agent prepared in Preparation Example 1, 3 wt% of the diphenyl biguanide compound prepared in Preparation Example 2, 2 wt% of the weak gel flow modifier prepared in Preparation Example 3, 1.5 wt% of the first crosslinking agent, 1.2 wt% of the retarder, 4 wt% of the filler, and the balance being water.

[0238] The first crosslinking agent comprises trimethylol ethane and propylenediamine in a mass ratio of 1:2; the retarder comprises hydroxyethylidene diphosphonic acid and sodium lignosulfonate in a mass ratio of 1:1; and the filler comprises quartz sand and hydrophilic nano silica in a mass ratio of 3:1.

[0239] According to the above formula, the composite resin sealant S6 was prepared by following the same steps as in Example 1.

[0240] Example 7

[0241] The composite resin sealing composition provided in this embodiment is obtained by replacing the diphenyl biguanide compound in Example 1 with an equal mass of dicyandiamide, while the other raw material types, raw material amounts and preparation steps are the same as in Example 1, resulting in composite resin sealing composition S7.

[0242] Example 8

[0243] The composite resin sealing composition provided in this embodiment is obtained by replacing the weak gel flow modifier in Example 1 with an equal mass of nanocellulose, and the other raw material types, raw material amounts and preparation steps are the same as in Example 1, resulting in composite resin sealing composition S8.

[0244] Example 9

[0245] The composite resin sealing composition provided in this embodiment is obtained by replacing the retarder in Example 1 with an equal mass of "hydroxyethylidene diphosphonic acid and aminotrimethylene phosphonic acid mixed in a mass ratio of 1:1". Other raw material types, raw material amounts and preparation steps are the same as in Example 1, resulting in composite resin sealing composition S9.

[0246] Comparative Example 1

[0247] The composite resin plugging composition provided in this comparative example is obtained by removing the weak gel flow modifier in Example 1, while the other raw material types, raw material amounts and preparation steps are the same as in Example 1, resulting in composite resin plugging composition D1.

[0248] Comparative Example 2

[0249] The composite resin sealing composition provided in this comparative example is obtained by replacing propylenediamine in the first crosslinking agent in Example 1 with an equal mass of trimethylolethane, and the other raw material types, raw material amounts and preparation steps are the same as in Example 1, resulting in composite resin sealing composition D2.

[0250] Comparative Example 3

[0251] The composite resin sealing composition provided in this comparative example is obtained by replacing trimethylolethane in the first crosslinking agent in Example 1 with an equal mass of propylenediamine, while the other raw material types, raw material amounts and preparation steps are the same as in Example 1, resulting in composite resin sealing composition D3.

[0252] Comparative Example 4

[0253] The composite resin sealing composition provided in this comparative example is obtained by removing the first crosslinking agent in Example 1, while the other raw material types, raw material amounts, and preparation steps are the same as in Example 1, resulting in composite resin sealing composition D4.

[0254] Comparative Example 5

[0255] The composite resin sealing composition provided in this comparative example is obtained by removing the retarder in Example 1, while the other raw material types, raw material amounts, and preparation steps are the same as in Example 1, resulting in composite resin sealing composition D5.

[0256] Comparative Example 6

[0257] The composite resin sealing composition provided in this comparative example is obtained by removing the hydrophilic nano-silica from the filler in Example 1, while the other raw material types, raw material amounts, and preparation steps are the same as in Example 1, resulting in composite resin sealing composition D6.

[0258] Comparative Example 7

[0259] The composite resin sealing composition provided in this comparative example is obtained by removing the quartz sand from the filler in Example 1, while keeping the other raw material types, raw material amounts, and preparation steps the same as in Example 1, resulting in composite resin sealing composition D7.

[0260] Comparative Example 8

[0261] The composite resin sealing composition provided in this comparative example is obtained by removing the filler in Example 1, while the other raw material types, raw material amounts and preparation steps are the same as in Example 1, resulting in composite resin sealing composition D8.

[0262] Comparative Example 9

[0263] The composite resin sealing composition provided in this comparative example is obtained by replacing the composite sealing agent prepared in Preparation Example 1 in Example 1 with an equal mass of the composite sealing agent prepared in Comparative Preparation Example 1. Other raw material types, raw material amounts and preparation steps are the same as in Example 1, resulting in composite resin sealing composition D9.

[0264] Comparative Example 10

[0265] The composite resin sealing composition provided in this comparative example is obtained by replacing the composite sealing agent prepared in Preparation Example 1 in Example 1 with an equal mass of the composite sealing agent prepared in Comparative Preparation Example 2. Other raw material types, raw material amounts and preparation steps are the same as in Example 1, resulting in composite resin sealing composition D10.

[0266] Comparative Example 11

[0267] The composite resin sealing composition provided in this comparative example is obtained by replacing the composite sealing agent prepared in Preparation Example 1 in Example 1 with an equal mass of the composite sealing agent prepared in Comparative Preparation Example 3. Other raw material types, raw material amounts and preparation steps are the same as in Example 1, resulting in composite resin sealing composition D11.

[0268] Comparative Example 12

[0269] The composite resin sealing composition provided in this comparative example is obtained by replacing the composite sealing agent prepared in Preparation Example 1 in Example 1 with an equal mass of the composite sealing agent prepared in Comparative Preparation Example 4. Other raw material types, raw material amounts and preparation steps are the same as in Example 1, resulting in composite resin sealing composition D12.

[0270] Comparative Example 13

[0271] The composite resin sealing composition provided in this comparative example is obtained by replacing the diphenyl biguanide compound prepared in Preparation Example 2 used in Example 1 with an equal mass of the diphenyl biguanide compound prepared in Comparative Preparation Example 5. Other raw material types, raw material amounts and preparation steps are the same as in Example 1, resulting in composite resin sealing composition D13.

[0272] Comparative Example 14

[0273] The composite resin sealing composition provided in this comparative example is obtained by replacing the diphenyl biguanide compound prepared in Preparation Example 2 used in Example 1 with an equal mass of the diphenyl biguanide compound prepared in Comparative Preparation Example 6. Other raw material types, raw material amounts and preparation steps are the same as in Example 1, resulting in composite resin sealing composition D14.

[0274] Comparative Example 15

[0275] The composite resin sealing composition provided in this comparative example is obtained by replacing the diphenyl biguanide compound prepared in Preparation Example 2 used in Example 1 with an equal mass of the diphenyl biguanide compound prepared in Comparative Preparation Example 7. Other raw material types, raw material amounts and preparation steps are the same as in Example 1, resulting in composite resin sealing composition D15.

[0276] Comparative Example 16

[0277] The composite resin plugging composition provided in this comparative example is obtained by replacing the weak gel flow modifier prepared in Preparation Example 3 in Example 1 with an equal mass of the weak gel flow modifier prepared in Comparative Preparation Example 8. Other raw material types, raw material amounts and preparation steps are the same as in Example 1, resulting in composite resin plugging composition D16.

[0278] Comparative Example 17

[0279] The composite resin plugging composition provided in this comparative example is obtained by replacing the weak gel flow modifier prepared in Preparation Example 3 in Example 1 with an equal mass of the weak gel flow modifier prepared in Comparative Preparation Example 9. Other raw material types, raw material amounts and preparation steps are the same as in Example 1, resulting in composite resin plugging composition D17.

[0280] Test Example 1

[0281] The rheological properties of the composite resin plugging compositions S1, S2, and D1 prepared in Examples 1, 2, and Comparative Example 1 were tested using a six-speed rotational viscometer (model ZNN-D6). Specifically, the tests included absolute viscosity, initial shear force, final shear force, apparent viscosity, plastic viscosity, and dynamic shear force at different rotational speeds. The results are shown in Table 1.

[0282] Table 1. Rheological test data of the plugging system

[0283]

[0284]

[0285] As shown in Table 1, the composite resin plugging compositions S1 and S2 exhibit good rheological properties. Furthermore, the comparison shows that the absolute viscosity, initial shear force, final shear force, apparent viscosity, plastic viscosity, and dynamic shear force of composite resin plugging compositions S1 and S2 at different rotation speeds are all higher than those of composite resin plugging composition D1. This indicates that the addition of the weak gel flow modifier in composite resin plugging compositions S1 and S2 helps to maintain the viscosity of the composite resin plugging compositions, thereby better suspending and dispersing the fillers added to the composite resin plugging compositions.

[0286] Test Example 2

[0287] Equal and appropriate amounts of the composite resin sealing compositions S1 to S6 and D1 to D8 prepared in Examples 1 to 6 and Comparative Examples 1 to 8 were weighed, placed into molds, and aged in a high-temperature aging oven at different temperatures for 48 hours. The compositions were then removed and subjected to uniaxial compressive strength tests to evaluate the high-temperature resistance of the composite resin sealing compositions. The results are shown in Table 2.

[0288] Table 2. Temperature resistance test data of composite resin plugging compositions

[0289]

[0290]

[0291] As shown in Table 2, the compressive strengths of the composite resin sealing compositions S1 to S6 prepared in Examples 1 to 6 after aging at 160℃, 180℃, 200℃, 220℃, 240℃ and 260℃ for 48 hours are not lower than 27MPa, 26MPa, 22.5MPa, 21.5MPa and 16MPa respectively. The compressive strength after aging decreases slowly with increasing temperature in the range of 160 to 240℃. The compressive strength after aging at 260℃ decreases by less than 42% compared to the compressive strength after aging at 160℃, proving that the composite resin sealing composition provided by the present invention has good temperature resistance after curing.

[0292] Furthermore, the composite resin sealing composition D1 prepared in Comparative Example 1 lacked a weak gel flow modifier compared to the composite resin sealing composition S1. Compared with S1, the compressive strength of composite resin sealing composition D1 decreased by 31.3%, 33.4%, 33.5%, 36.7%, 39.7%, and 50% respectively after aging at 160℃, 180℃, 200℃, 220℃, 240℃, and 260℃ for 48 hours. It can be seen that the lack of a weak gel flow modifier in composite resin sealing composition D1 leads to a significant decrease in its high-temperature resistance after curing. Compared with composite resin sealing composition S1, composite resin sealing composition D5 prepared in Comparative Example 5 lacks a retarder. After aging at 160℃, 180℃, 200℃, 220℃ and 240℃ for 48h, the compressive strength of composite resin sealing composition D5 decreased by 9.4%, 5.3%, 5.7%, 7.2% and 6.9% respectively. It can be seen that the lack of retarder in composite resin sealing composition S5 leads to a decrease in its high-temperature resistance after curing.

[0293] Furthermore, compared to composite resin sealing composition D4, composite resin sealing compositions S1, D2, and D3 respectively added a mixture of propylenediamine and trihydroxyethylmethane, propylenediamine, and trihydroxyethylmethane. As a result, compared to composite resin sealing composition D4, the compressive strength of composite resin sealing compositions S1, D2, and D3 increased by 99.2%, 10%, and 21.5% respectively after aging at 160℃ for 48 hours; by 95%, 10%, and 22% respectively after aging at 180℃ for 48 hours; and by 103.7%, 13%, and 29.8% respectively after aging at 200℃ for 48 hours. After aging at 220℃ for 48 hours, the compressive strength increased by 102.6%, 10%, and 24% respectively; after aging at 240℃ for 48 hours, the compressive strength increased by 132.7%, 17%, and 31.2% respectively; and after aging at 260℃ for 48 hours, the compressive strength increased by 215.9%, 34.4%, and 42% respectively. That is, the increase rate of compressive strength after aging after simultaneously adding propylenediamine and trihydroxyethylmethane is greater than the sum of the increase rates of compressive strength after aging after adding propylenediamine alone and adding trihydroxyethylmethane alone. In the first crosslinking agent, propylenediamine and trihydroxyethylmethane synergistically improve the high temperature resistance of the composite resin plugging composition.

[0294] Furthermore, compared to composite resin sealing composition D8, composite resin sealing compositions S1, D6, and D7 respectively added a mixture of quartz sand and hydrophilic nano-silica, quartz sand, and hydrophilic nano-silica. This resulted in the following increases in compressive strength compared to composite resin sealing composition D8: after aging at 160℃ for 48 hours, the compressive strength of composite resin sealing compositions S1, D6, and D7 increased by 40.9%, 25.7%, and 5% respectively; after aging at 180℃ for 48 hours, the compressive strength increased by 34.9%, 22.1%, and 0.9% respectively; and after aging at 200℃ for 48 hours, the compressive strength increased by [missing information]. The compressive strength increased by 34.9%, 26%, and 1.6% respectively after aging at 220℃ for 48 hours. After aging at 240℃ for 48 hours, the compressive strength increased by 41.8%, 29.6%, and 4.1% respectively. That is, the increase rate of compressive strength after aging after adding both quartz sand and hydrophilic nano-silica is greater than the sum of the increase rates of compressive strength after aging after adding quartz sand alone and adding hydrophilic nano-silica alone. The quartz sand and hydrophilic nano-silica in the filler synergistically improve the high temperature resistance of the composite resin sealing composition.

[0295] Test Example 3

[0296] The initial curing time, optimal curing time, and post-curing strength of the composite resin sealing compositions S1 to S9 and D1 to D17 prepared in Examples 1 to 9 and Comparative Examples 1 to 17 were tested. The specific steps are as follows:

[0297] (1) Initial curing time

[0298] Take equal and appropriate amounts of composite resin sealing compositions S1 to S9 and D1 to D17 and put them into a heat-resistant mold. Place them in a high-temperature aging oven and cure them at 240°C. Observe the curing of the composite resin sealing compositions at regular intervals. When no composite resin sealing composition flows out within 30 seconds of inverting the heat-resistant mold, it is determined that the composite resin sealing composition has completed the initial curing. This observation time point is the initial curing time of the composite resin sealing composition.

[0299] (2) Optimal curing time and post-curing strength

[0300] Take equal and appropriate amounts of composite resin sealing compositions S1 to S9 and D1 to D17 and put them into a heat-resistant mold. Place them in a high-temperature aging oven and cure them at 240°C. Take out the composite resin sealing compositions at regular intervals to perform uniaxial compressive strength tests. Record the curing time and the corresponding compressive strength. The curing time corresponding to the maximum compressive strength is the optimal curing time of the composite resin sealing composition at 240°C.

[0301] The test results of the initial curing time, optimal curing time and corresponding compressive strength of each composite resin sealing composition at 240℃ are shown in Table 3.

[0302] Table 3. Initial curing time, optimum curing time and corresponding compressive strength of composite resin sealing compositions at 240℃

[0303]

[0304]

[0305] As shown in Table 3, the composite resin sealing compositions prepared in Examples 1 to 9 achieved initial curing at 240°C for 3 to 5 hours. When the heating time was extended to 4-7.5 hours, they reached optimal curing, with compressive strengths all exceeding 20 MPa, and some even exceeding 25 MPa. The composite resin sealing compositions D1 to D17 prepared in Comparative Examples 1 to 17, compared to the composite resin sealing composition S1 prepared in Example 1, had various missing or altered raw materials. Their initial curing time and optimal curing time also varied with the formula, demonstrating that the initial curing time, optimal curing time, and compressive strength at the optimal curing time of the composite resin sealing compositions provided by this invention can be flexibly adjusted by modifying the formula as needed. Furthermore, the compressive strength achieved by composite resin sealing compositions D1 to D17 at the optimal curing time was lower than that of composite resin sealing composition S1, proving that only composite resin sealing compositions prepared according to the formula provided by this invention can achieve higher compressive strength at the optimal curing time. Changes in the type or amount of raw materials, or the absence of raw materials, will reduce the compressive strength achievable by the composite resin sealing compositions at the optimal curing time.

[0306] Test Example 4

[0307] The crack sealing effect of the composite resin sealing compositions S1 to S9 and D1 to D17 prepared in Examples 1 to 9 and Comparative Examples 1 to 17 was evaluated using a high-temperature and high-pressure leak sealing test device. The specific steps are as follows:

[0308] Weigh out equal and appropriate amounts of composite resin sealing compositions S1 to S9 and D1 to D17, and fill them into steel crack models (10cm long and 3.0mm wide). Seal the models and place them in a high-temperature aging oven for curing. The curing temperature is 240℃ and the curing time is the optimal curing time.

[0309] After the composite resin plugging composition has cured, the steel crack model is taken out of the high-temperature aging furnace and naturally cooled to room temperature. Then, a high-volume horizontal flow pump is used to inject slurry for pressurization. During the pressurization process, the pressure at the inlet end of the steel crack model is monitored in real time. The highest pressure when the slurry leaks from the outlet end of the steel crack model is observed and recorded, which is the pressure resistance of the composite resin plugging composition to the crack.

[0310] The results are shown in Table 4.

[0311] Table 4. Pressure resistance of composite resin sealing compositions for crack sealing

[0312]

[0313]

[0314] As shown in Table 4, the composite resin sealing compositions prepared in Examples 1 to 9, after curing at 240°C for an optimal curing time of 4-7.5 hours, exhibit a pressure-bearing sealing capacity of over 12 MPa for cracks 10 cm long and 3.0 mm wide, even exceeding 17 MPa, demonstrating good crack sealing performance. Comparative Examples 1 to 17, with their respective missing or altered raw materials compared to Composite Resin Sealing Composition S1 prepared in Example 1, showed a decrease in pressure-bearing sealing capacity for cracks 10 cm long and 3.0 mm wide after curing at 240°C for their optimal curing times, resulting in poorer crack sealing performance. This demonstrates that the composite resin sealing compositions prepared according to the formulation provided by this invention achieve good crack sealing performance only after curing at the optimal curing time. Changes in the type or amount of raw materials, or the absence of raw materials, will reduce the crack sealing performance of the composite resin sealing compositions.

[0315] While the present invention has been described with reference to specific embodiments, those skilled in the art will understand that various changes can be made without departing from the true spirit and scope of the invention. Furthermore, numerous modifications can be made to the subject, spirit, and scope of the invention to suit specific situations, materials, material compositions, and methods. All such modifications are included within the scope of the claims of the present invention.

Claims

1. A composite resin sealing composition, the raw materials of which include a composite sealing agent, a latent curing agent, a flow pattern modifier, a first crosslinking agent, a retarder, a filler, and water; The raw materials for the composite sealant include water-based epoxy resin, amino-terminated polyether, polyimide resin, melamine-formaldehyde resin, a second crosslinking agent, and a polymer; wherein, By weight, the waterborne epoxy resin comprises 10-30 parts epoxy resin, 0.3-0.8 parts amino-terminated polyether, 10-20 parts polyimide resin, 5-15 parts melamine-formaldehyde resin, 0.8-0.2 parts second crosslinking agent, and 0.3-0.8 parts polymer. The polymer is a copolymer of acrylamide, acrylic acid, N-vinylpyrrolidone and methacryloyloxyethyl dimethyl benzyl ammonium halide or a copolymer of acrylamide, acrylic acid, N-vinylpyrrolidone and methacryloyloxyethyl dimethyl alkyl ammonium halide.

2. The composite resin sealing composition according to claim 1, characterized in that, The total mass of the raw materials in the composite resin sealing composition is 100%. The raw materials of the composite resin sealing composition include 20-50 wt% of the composite sealing agent, 0.5-5.0 wt% of the latent curing agent, 0.05-3.0 wt% of the flow modifier, 0.05-2.0 wt% of the first crosslinking agent, 0.5-1.5 wt% of the retarder, 3-10 wt% of the filler, and the balance being water.

3. The composite resin sealing composition according to claim 2, characterized in that, The second crosslinking agent is a mixture of diethylenetriamine and hydroxypropyl methacrylate.

4. The composite resin sealing composition according to claim 3, characterized in that, In the second crosslinking agent, the mass ratio of diethylenetriamine to hydroxypropyl methacrylate is (2-4):(1-3); and / or In the polymer, the molar ratio of acrylamide, acrylic acid, N-vinylpyrrolidone and methacryloyloxyethyl dimethyl benzyl ammonium halide or the molar ratio of acrylamide, acrylic acid, N-vinylpyrrolidone and methacryloyloxyethyl dimethyl alkyl ammonium halide is (4-2):(3-2):(2-1):(2-1); Preferably, the polymer has a molecular weight of 15,000.

5. The composite resin sealing composition according to claim 4, characterized in that, The composite sealing agent is prepared in the following manner: The aqueous epoxy resin and the amino-terminated polyether are subjected to a first reaction in water to obtain an amino-terminated polyether modified epoxy resin. The amino-terminated polyether modified epoxy resin, polyimide resin, and melamine-formaldehyde resin are mixed to obtain a resin mixture; The second crosslinking agent, polymer, and resin mixture are mixed, dried, and pulverized to obtain the composite resin sealant.

6. The composite resin sealing composition according to claim 5, characterized in that, The temperature of the first reaction is 70-90℃; and / or the duration is 0.5-5h.

7. The composite resin plugging composition according to any one of claims 1 to 6, characterized in that, The latent curing agent is a diphenyl biguanide compound and / or dicyandiamide.

8. The composite resin sealing composition according to claim 7, characterized in that, The raw materials for the diphenylbiguanide compounds include, by weight: 20-30 parts sodium dicyandiamide, 10-20 parts diaminodiphenyl sulfone, and 5-15 parts 4,4'-diaminodiphenylmethane.

9. The composite resin sealing composition according to claim 8, characterized in that, The diphenylbiguanide compound was prepared according to the following steps: The sodium dicyandiamide, diaminodiphenyl sulfone, and 4,4'-diaminodiphenylmethane were subjected to a second reaction in an alcohol solvent, and the pH was adjusted to acidic to obtain a reaction product solution. The alcohol solvent in the reaction product solution is removed, and the product is washed and dried to obtain the diphenylbiguanide compound.

10. The composite resin sealing composition according to claim 9, characterized in that, The second reaction is carried out in an inert gas atmosphere; and / or The second reaction temperature is 70-90℃; and / or the duration is 1-2 hours; and / or The acidity refers to a pH of 4-5.

11. The composite resin plugging composition according to any one of claims 1 to 6, characterized in that, The flow pattern regulator is a weak gel flow pattern regulator and / or nanocellulose; The raw materials of the weak gel flow modifier include, by weight: 10-20 parts xanthan gum, 20-30 parts acrylic acid, 20-30 parts 2-acrylamide-2-methylpropanesulfonic acid, 5-15 parts N-vinylpyrrolidone, 2-4 parts organoboron crosslinking agent and 1-2 parts initiator. Preferably, the initiator is a mixture of potassium persulfate and dimethyl azobisisobutyrate; Preferably, the mass ratio of potassium persulfate to dimethyl azobisisobutyrate is (1-3):(2-4).

12. The composite resin sealing composition according to claim 11, characterized in that, The weak gel flow modifier was prepared according to the following steps: The xanthan gum, acrylic acid, 2-acrylamide-2-methylpropanesulfonic acid, N-vinylpyrrolidone and organoboron crosslinking agent are mixed in water, the pH is adjusted to neutral, and a third reaction is carried out under the action of an initiator. The mixture is then washed, dried and pulverized to obtain the weak gel flow modifier.

13. The composite resin sealing composition according to claim 12, characterized in that, The third reaction is carried out in an inert gas atmosphere; and / or The temperature of the third reaction is 60-80℃; and / or the duration is 10-20 min.

14. The composite resin plugging composition according to any one of claims 1 to 6, characterized in that, The first crosslinking agent is a mixture of trimethylolethane and propylenediamine; and / or The retarder is at least one of hydroxyethylidene diphosphonic acid, sodium lignosulfonate and aminotrimethylene phosphonic acid; And / or the filler is a mixture of quartz sand and hydrophilic nano silica.

15. The composite resin sealing composition according to claim 14, characterized in that, In the first crosslinking agent, the mass ratio of trimethylolethane to propylenediamine is 1:(1-3); and / or The retarder is a mixture of hydroxyethylidene diphosphonic acid and sodium lignosulfonate in a mass ratio of 1:1; and / or In the filler, the mass ratio of the quartz sand to the hydrophilic nano silica is (3-5):(1-2).

16. The composite resin sealing composition according to claim 15, characterized in that, The composite sealing agent has a particle size of 1-3 mm; and / or The flow pattern regulator has a particle size of 1-1.5 mm; and / or The hydrophilic nano-silica has a particle size of 20-100 nm.

17. A method for preparing the composite resin plugging composition according to any one of claims 1 to 16, characterized in that, Includes the following steps: The composite sealant is dispersed in water, mixed with the crosslinking agent, and then the latent curing agent, retarder, flow modifier and filler are added to obtain the composite resin sealant composition.

18. The application of the composite resin plugging composition according to any one of claims 1 to 16 or the composite resin plugging composition prepared by the method of claim 17 in reservoir plugging; Preferably, the application temperature is 160-240℃.

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