Nano-particle reinforced gel material for blocking gas reservoir water channeling channel as well as preparation method and application of nano-particle reinforced gel material

Abstract

The invention provides a nano-particle reinforced gel material for blocking a gas reservoir water channeling channel and a preparation method and application thereof, and the nano-particle reinforced gel material comprises the following components in percentage by mass: 1%-2% of an acrylamide copolymer, 0.015%-0.020% of a cross-linking agent and 0.10%-0.15% of nano-particles. The gel material provided by the invention has the advantages of short gelling time, good mechanical properties, high gelling strength, high temperature resistance, salt resistance, high stability, long effective action time, capability of realizing high-strength effective plugging on water channeling channels, simple components and easiness in preparation and construction.

Description

Technical Field

[0001] This invention belongs to the field of oilfield development technology, specifically relating to a nanoparticle-reinforced gel material for sealing gas reservoirs and its preparation method. Background Technology

[0002] As natural gas plays an increasingly important role in the energy structure, efficient development of gas reservoirs has become crucial. Natural gas extraction relies on the continuous production capacity of gas wells, and factors such as reservoir properties, pressure, and temperature significantly impact well production. Gas reservoir environments are complex; during development, as formation pressure decreases, adjacent edge water, bottom water, or interlayer water can easily infiltrate the producing layer under pressure differential. Due to the prevalent strong heterogeneity of reservoirs, such as high-permeability bands and fractures, water flow easily forms "water channeling" along these pathways.

[0003] Water channeling is typically closely related to factors such as reservoir pore structure, fracture permeability, pressure, and temperature. When there are significant pressure differences, well-developed fractures, or high reservoir water saturation, formation water can enter the vicinity of the gas well along these permeable fractures. This can lead to premature water breakthrough at the well, impede the smooth flow of natural gas into the wellbore, and consequently reduce the well's production capacity, or even cause complete water flooding and shutdown. Water channeling is particularly pronounced in harsh formation environments such as high-temperature and high-salinity areas, making the water intrusion problem more complex.

[0004] Addressing this issue in gas reservoir development, sealing water channeling is one of the key technologies for improving gas well production and the economic benefits of gas fields. Commonly used techniques for sealing water channeling include injecting sealing agents and foam lifting. These techniques effectively block the channels for formation water flow and prevent further water channeling.

[0005] For example, CN118704935A discloses a gel composite water plugging method for heavy oil thermal recovery wells and its application, which involves sequentially injecting foaming agent, nitrogen, gel profile control agent, fly ash profile control agent, and nitrogen to form a slug to seal water channeling. CN116554846A discloses a gel plugging agent suitable for low-permeability and ultra-low-permeability fractured reservoirs and its preparation method, including a low molecular weight, low-hydrolysis degree polymer main agent, a crosslinking agent, and a retarder. However, traditional plugging technologies often face a series of challenges. For example, deep gas reservoirs have harsh environments, generally characterized by high temperatures and high salinity. Traditional plugging agents or foam systems are prone to pyrolysis and salt-sensitive failure, making long-term stable plugging difficult. Under conditions of high temperature, high salinity, and pressure fluctuations, insufficient structural integrity or plugging strength of the plugging agent can easily lead to short-term failure, and frequent injection of plugging agents results in higher costs and operational complexity.

[0006] Therefore, developing sealing materials with excellent high-temperature and high-salt resistance and high-efficiency sealing capabilities is the core technological direction for achieving efficient water channeling control and ensuring efficient gas field development. Summary of the Invention

[0007] The purpose of this invention is to provide a nanoparticle-reinforced gel material for sealing water channeling in gas reservoirs, its preparation method and application. The material has high temperature and salt resistance and can achieve efficient sealing of water channeling.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a nanoparticle-reinforced gel material, wherein the composition of the nanoparticle-reinforced gel material, by mass percentage, comprises: 1%-2% acrylamide-based copolymer, 0.015%-0.020% crosslinking agent, and 0.10%-0.15% nanoparticles.

[0010] The gel material provided by this invention uses acrylamide copolymer as the main gelling agent and is reinforced by crosslinking agent and nanoparticles. The gel material is formed by specific selection and ratio of the three components. It has excellent high temperature resistance and salt resistance, high material stability, good mechanical properties, and extremely strong shear resistance. It can achieve high-strength sealing of water channeling, reduce gas flow resistance, and improve gas well production and oilfield economic benefits.

[0011] In the nanoparticle-reinforced gel material, the mass content of the acrylamide-based copolymer is 1%-2%, for example, it can be 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9% or 2%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0012] In the nanoparticle-reinforced gel material, the mass content of the crosslinking agent is 0.015%-0.020%, for example, it can be 0.015%, 0.016%, 0.017%, 0.018%, 0.019% or 0.020%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0013] In the nanoparticle-reinforced gel material, the mass content of nanoparticles is 0.10%-0.15%, for example, it can be 0.10%, 0.11%, 0.12%, 0.13%, 0.14% or 0.15%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0014] Preferably, the acrylamide-based copolymer includes at least one of an acrylamide copolymer containing sulfonic acid groups and / or cyclic amide groups, a hydrophobic associative acrylamide copolymer, or an amphoteric acrylamide copolymer.

[0015] Preferably, the acrylamide copolymer containing sulfonic acid groups and / or cyclic amide groups includes at least one of N-vinylpyrrolidone-acrylamide copolymer, 2-acrylamido-2-methylpropanesulfonic acid-acrylamide copolymer, or 2-acrylamido-2-methylpropanesulfonic acid-N-vinylpyrrolidone-acrylamide terpolymer.

[0016] Preferably, the N-vinylpyrrolidone-acrylamide copolymer comprises a partially hydrolyzed N-vinylpyrrolidone-acrylamide copolymer.

[0017] Preferably, the degree of hydrolysis of the partially hydrolyzed N-vinylpyrrolidone-acrylamide copolymer is 10%-25%, for example, it can be 10%, 12%, 15%, 18%, 20%, 22% or 25%, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0018] Preferably, the mass content of 2-acrylamido-2-methylpropanesulfonic acid monomer in the 2-acrylamido-2-methylpropanesulfonic acid-acrylamide copolymer is 25%-40%, for example, it can be 20%, 25%, 30%, 35% or 40%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0019] Preferably, in the terpolymer of 2-acrylamido-2-methylpropanesulfonic acid-N-vinylpyrrolidone-acrylamide, the monomer content of N-vinylpyrrolidone is 10-30 mol%, and the monomer content of 2-acrylamido-2-methylpropanesulfonic acid is 15-40 mol%.

[0020] The monomer content of the N-vinylpyrrolidone is 10-30 mol%, for example, it can be 10 mol%, 15 mol%, 20 mol%, 25 mol%, or 30 mol%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0021] The monomer content of the 2-acrylamido-2-methylpropanesulfonic acid is 15-40 mol%, for example, it can be 15 mol%, 20 mol%, 25 mol%, 30 mol%, 35 mol%, or 40 mol%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0022] Preferably, the hydrophobically associating acrylamide copolymer comprises a hydrophobically associating 2-acrylamido-2-methylpropanesulfonic acid-N-vinylpyrrolidone-acrylamide terpolymer.

[0023] Preferably, the degree of hydrolysis of the hydrophobically associating acrylamide copolymer is 5%-15%, for example, it can be 5%, 8%, 10%, 12% or 15%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0024] Preferably, the zwitterionic acrylamide copolymer includes a betaine-type acrylamide copolymer.

[0025] In this invention, the partially hydrolyzed N-vinylpyrrolidone-acrylamide copolymer, 2-acrylamido-2-methylpropanesulfonic acid-acrylamide copolymer, 2-acrylamido-2-methylpropanesulfonic acid-N-vinylpyrrolidone-acrylamide terpolymer, hydrophobically associated 2-acrylamido-2-methylpropanesulfonic acid-N-vinylpyrrolidone-acrylamide terpolymer, and betaine-type acrylamide copolymer can all be copolymers conventional in the art.

[0026] Preferably, the crosslinking agent includes at least one of chromium-based crosslinking agents, zirconium-based crosslinking agents, or phenolic crosslinking agents. Typical but non-limiting combinations include combinations of chromium-based crosslinking agents and zirconium-based crosslinking agents, combinations of zirconium-based crosslinking agents and phenolic crosslinking agents, combinations of chromium-based crosslinking agents and phenolic crosslinking agents, or combinations of chromium-based crosslinking agents, zirconium-based crosslinking agents, and phenolic crosslinking agents.

[0027] Preferably, the chromium-based crosslinking agent includes chromium acetate and / or chromium malonate.

[0028] Preferably, the zirconium-based crosslinking agent includes at least one of zirconium oxychloride, zirconium acetate, or zirconium tetrachloride. Typical but non-limiting combinations include combinations of zirconium oxychloride and zirconium acetate, combinations of zirconium acetate and zirconium tetrachloride, combinations of zirconium oxychloride and zirconium tetrachloride, or combinations of zirconium oxychloride, zirconium acetate, and zirconium tetrachloride.

[0029] Preferably, the phenolic crosslinking agent comprises phenolic resin.

[0030] Preferably, the average particle size of the nanoparticles is 10-200 nm, for example, it can be 10 nm, 30 nm, 50 nm, 80 nm, 100 nm, 120 nm, 150 nm, 180 nm or 200 nm, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0031] Preferably, the specific surface area of ​​the nanoparticles is 60-300 m². 2 / g, for example, could be 60m 2 / g, 100m2 / g, 150m 2 / g、200m 2 / g、250m 2 / g or 300m 2 / g, but not limited to the listed values, other unlisted values ​​within the range also apply.

[0032] Preferably, the nanoparticles include at least one of metal oxide nanoparticles, non-metal oxide nanoparticles, carbon-based nanoparticles, or polymer nanoparticles. Typical but non-limiting combinations include combinations of metal oxide nanoparticles and non-metal oxide nanoparticles, combinations of carbon-based nanoparticles and polymer nanoparticles, combinations of metal oxide nanoparticles, non-metal oxide nanoparticles and carbon-based nanoparticles, or combinations of metal oxide nanoparticles, non-metal oxide nanoparticles, carbon-based nanoparticles and polymer nanoparticles.

[0033] Preferably, the metal oxide nanoparticles include at least one of nano-alumina, nano-titanium oxide, or nano-zinc oxide. Typical but non-limiting combinations include a combination of nano-alumina and nano-titanium oxide, a combination of nano-titanium oxide and nano-zinc oxide, a combination of nano-alumina and nano-zinc oxide, or a combination of nano-alumina, nano-titanium oxide, and nano-zinc oxide, preferably nano-alumina.

[0034] Preferably, the non-metallic oxide nanoparticles include nano-silica.

[0035] Preferably, the carbon-based nanoparticles include graphene and / or carbon nanotubes.

[0036] Preferably, the polymer nanoparticles comprise nano-polyethyleneimine and / or nano-chitosan.

[0037] In a second aspect, the present invention provides a method for preparing the nanoparticle-reinforced gel material described in the first aspect, the method comprising:

[0038] According to the composition of the nanoparticle-reinforced gel material, water is mixed and dispersed with a polymer, a crosslinking agent and nanoparticles to obtain the nanoparticle-reinforced gel material.

[0039] Preferably, the mixing method includes stirring.

[0040] Preferably, the stirring speed is 1000-3000 r / min, for example, it can be 1000 r / min, 1500 r / min, 2000 r / min, 2500 r / min or 3000 r / min, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0041] Preferably, the mixing temperature is 50-70°C, for example, 50°C, 55°C, 60°C, 65°C or 70°C, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0042] Thirdly, the present invention provides an application of the nanoparticle-reinforced gel material described in the first aspect, wherein the nanoparticle-reinforced gel material is used as a plugging agent for water channeling in natural gas well development.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The gel material provided by this invention has a short gelation time, good mechanical properties, high gel strength, high temperature and salt resistance, high stability, long effective action time, and can effectively seal water channeling. It has a simple composition and is easy to prepare and apply. Attached Figure Description

[0045] Figure 1 This is a graph showing the change in gelation properties of the nanoparticle-reinforced gel material provided in Example 1 as a function of mineralization.

[0046] Figure 2 This is a graph showing the change in gelation properties of the nanoparticle-reinforced gel material provided in Example 1 as a function of pH. Detailed Implementation

[0047] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0048] This invention may also employ conventional partially hydrolyzed N-vinylpyrrolidone-acrylamide copolymers, 2-acrylamido-2-methylpropanesulfonic acid-acrylamide copolymers, 2-acrylamido-2-methylpropanesulfonic acid-N-vinylpyrrolidone-acrylamide terpolymers, hydrophobically associated 2-acrylamido-2-methylpropanesulfonic acid-N-vinylpyrrolidone-acrylamide terpolymers, and betaine-type acrylamide copolymers. For ease of comparison, the following examples and comparative examples consistently use the following substances:

[0049] The partially hydrolyzed N-vinylpyrrolidone-acrylamide copolymer has an acrylamide monomer content of 80 wt%, an N-vinylpyrrolidone monomer content of 20 wt%, an acrylamide hydrolysis unit, a degree of hydrolysis of 20%, and a weight-average molecular weight of 500,000 g / mol.

[0050] The 2-acrylamido-2-methylpropanesulfonic acid-acrylamide copolymer has a 2-acrylamido-2-methylpropanesulfonic acid monomer content of 30 wt%, an acrylamide monomer content of 70 wt%, and a weight-average molecular weight of 500,000 g / mol.

[0051] The terpolymer of 2-acrylamido-2-methylpropanesulfonic acid-N-vinylpyrrolidone-acrylamide has the following composition: 30 mol% 2-acrylamido-2-methylpropanesulfonic acid monomer, 20 mol% N-vinylpyrrolidone monomer, 50 mol% acrylamide monomer, and a weight-average molecular weight of 600,000 g / mol.

[0052] The hydrophobically associated 2-acrylamido-2-methylpropanesulfonic acid-N-vinylpyrrolidone-acrylamide terpolymer comprises 30 mol% 2-acrylamido-2-methylpropanesulfonic acid monomer, 20 mol% N-vinylpyrrolidone monomer, 48 mol% acrylamide monomer, 2 mol% octadecyl acrylate as the hydrophobic associating monomer, acrylamide as the hydrolysis unit, a degree of hydrolysis of 10%, and a weight-average molecular weight of 500,000 g / mol.

[0053] The betaine-type acrylamide copolymer has a betaine monomer of 3-(3-methacrylamido-1-dimethylaminopropyl)-2-hydroxypropylsulfonic acid, with an acrylamide monomer content of 70 wt% and a betaine monomer content of 30 wt%, and a weight-average molecular weight of 600,000 g / mol.

[0054] The copolymers mentioned above were synthesized and provided by Southwest Petroleum University.

[0055] Example 1

[0056] This embodiment provides a nanoparticle-reinforced gel material, the composition of which, by mass percentage, includes: 1.5% acrylamide-based copolymer, 0.018% crosslinking agent, 0.12% nanoparticles, and the balance being water.

[0057] The acrylamide copolymer is a 2-acrylamido-2-methylpropanesulfonic acid-acrylamido copolymer.

[0058] The crosslinking agent is zirconium acetate.

[0059] The nanoparticles used are nano-alumina, with an average particle size of 50 nm and a specific surface area of ​​120 m². 2 / g.

[0060] The preparation method of the nanoparticle-reinforced gel material is as follows:

[0061] Using a thermostatic magnetic stirrer, set the temperature to 60°C, weigh deionized water, and add acrylamide-based copolymer, crosslinking agent, and nanoparticles according to the composition of the nanoparticle-reinforced gel material. Set the speed to 2000 r / min and stir for 15 min to fully dissolve the nanoparticle-reinforced gel material.

[0062] Example 2

[0063] This embodiment provides a nanoparticle-reinforced gel material, the composition of which, by mass percentage, includes: 1.5% acrylamide-based copolymer, 0.018% crosslinking agent, 0.12% nanoparticles, and the balance being water.

[0064] The acrylamide copolymer is a 2-acrylamido-2-methylpropanesulfonic acid-acrylamido copolymer.

[0065] The crosslinking agent is chromium acetate.

[0066] The nanoparticles are made of nano-silica, with an average particle size of 30 nm and a specific surface area of ​​150 m². 2 / g.

[0067] The preparation method of the nanoparticle-reinforced gel material is the same as that in Example 1.

[0068] Example 3

[0069] This embodiment provides a nanoparticle-reinforced gel material, the composition of which, by mass percentage, includes: 1.5% acrylamide-based copolymer, 0.018% crosslinking agent, 0.12% nanoparticles, and the balance being water.

[0070] The acrylamide-based copolymer is a partially hydrolyzed N-vinylpyrrolidone-acrylamide copolymer.

[0071] The crosslinking agent is zirconium acetate.

[0072] The nanoparticles used are nano-alumina, with an average particle size of 50 nm and a specific surface area of ​​120 m². 2 / g.

[0073] The preparation method of the nanoparticle-reinforced gel material is the same as that in Example 1.

[0074] Example 4

[0075] This embodiment provides a nanoparticle-reinforced gel material, the composition of which, by mass percentage, includes: 1.5% acrylamide-based copolymer, 0.018% crosslinking agent, 0.12% nanoparticles, and the balance being water.

[0076] The acrylamide-based copolymer is a hydrophobically associated 2-acrylamido-2-methylpropanesulfonic acid-N-vinylpyrrolidone-acrylamide terpolymer.

[0077] The crosslinking agent is zirconium acetate.

[0078] The nanoparticles of silicon dioxide have an average particle size of 30 nm and a specific surface area of ​​150 m². 2 / g.

[0079] The preparation method of the nanoparticle-reinforced gel material is the same as that in Example 1.

[0080] Example 5

[0081] This embodiment provides a nanoparticle-reinforced gel material, the composition of which, by mass percentage, includes: 1% acrylamide-based copolymer, 0.020% crosslinking agent, 0.15% nanoparticles, and the balance being water.

[0082] The acrylamide copolymer is a 2-acrylamido-2-methylpropanesulfonic acid-acrylamido copolymer.

[0083] The crosslinking agent is zirconium acetate.

[0084] The nanoparticles used are nano-alumina, with an average particle size of 50 nm and a specific surface area of ​​120 m². 2 / g.

[0085] The preparation method of the nanoparticle-reinforced gel material is the same as that in Example 1.

[0086] Example 6

[0087] This embodiment provides a nanoparticle-reinforced gel material, the composition of which, by mass percentage, includes: 2% acrylamide-based copolymer, 0.015% crosslinking agent, 0.10% nanoparticles, and the balance being water.

[0088] The acrylamide copolymer is a 2-acrylamido-2-methylpropanesulfonic acid-acrylamido copolymer.

[0089] The crosslinking agent is zirconium acetate.

[0090] The nanoparticles used are nano-alumina, with an average particle size of 50 nm and a specific surface area of ​​120 m². 2 / g.

[0091] The preparation method of the nanoparticle-reinforced gel material is the same as that in Example 1.

[0092] Example 7

[0093] This embodiment provides a nanoparticle-reinforced gel material. Compared with Example 1, the acrylamide-based copolymer is replaced by a betaine-type acrylamide copolymer in equal mass, and all other aspects are the same as in Example 1.

[0094] Example 8

[0095] This embodiment provides a nanoparticle-reinforced gel material. Compared with Example 1, nano-alumina is replaced with nano-titanium oxide by mass, and all other aspects are the same as in Example 1.

[0096] Comparative Example 1

[0097] This comparative example provides a gel material that, compared to Example 1, does not contain nanoparticles; instead, the nanoparticles are replaced with water at the same mass, while all other aspects are the same as in Example 1.

[0098] Comparative Example 2

[0099] This comparative example provides a nanoparticle-reinforced gel material. Compared with Example 1, the content of nanoparticles is set to 0.25%, and the rest are the same as in Example 1.

[0100] Comparative Example 3

[0101] This comparative example provides a nanoparticle-reinforced gel material. Compared with Example 1, the content of acrylamide-based copolymer is set to 0.5%, and the rest are the same as in Example 1.

[0102] Comparative Example 4

[0103] This comparative example provides a nanoparticle-reinforced gel material. Compared with Example 1, the content of acrylamide-based copolymer is set to 2.5%, and the rest are the same as in Example 1.

[0104] Performance testing

[0105] The static properties of the gel materials provided in the examples and comparative examples were evaluated.

[0106] The gel material solution was stirred at 3000 rpm using a Waring stirrer and aged in a constant temperature drying oven at 110℃. The Sydansk bottle test method was used to test the gelation time, gel strength, and dehydration rate at different times. The storage modulus G' and loss modulus G" were determined by frequency scanning using an RS600HAKKE rheometer.

[0107] The gel material prepared in Example 1 was subjected to gelation time and gelation strength tests in environments with different mineralization and pH values. The results are as follows: Figure 1 and Figure 2As shown in the figure, the gel material of the present invention exhibits good salt resistance and strong pH stability, with a salt concentration tolerance >20×10⁻⁶. 4 ppm.

[0108] The results are shown in Table 1. (Gel strength increases from E to I)

[0109] Table 1

[0110]

[0111]

[0112] As shown in Table 1, the gel material provided by this invention has a short gelation time, high gel strength after long-term aging, low dehydration rate, and good performance. Comparing the results of Example 1 and Example 2, nano-alumina (50nm), due to its Lewis acidic surface, tendency to become positively charged in the application environment, and extremely high thermal stability, can form stronger interfacial interactions (electrostatic attraction, coordination, strong hydrogen bonding) with the sulfonate and amide groups in the 2-acrylamido-2-methylpropanesulfonic acid-acrylamide copolymer, which are more conducive to improving the temperature and salt resistance. This stronger interaction can more effectively restrict chain segment movement at high temperatures, stabilize the polymer network, and partially resist the shielding effect of salt ions on negative charges. Nano-alumina particles have a greater impact on improving the temperature and salt resistance of the copolymer. Compared with Examples 3 and 4, the introduction of N-vinylpyrrolidone monomer in Example 1 further improves the temperature and salt resistance of the material and improves the mechanical strength of the polymer. Compared with Example 7, the betaine-type acrylamide copolymer exhibits weaker thermo-salt stability than the 2-acrylamido-2-methylpropanesulfonic acid-acrylamidamide copolymer, with a higher dehydration rate and greater loss modulus after heating for a period of time. Compared with Example 8, while nano-titanium oxide has the advantage of small particle size, its overall reinforcing effect is weaker due to limitations such as negative charge repulsion, potential phase transition, and photocatalytic degradation risks. Nano-alumina particles show a more significant improvement in material performance. Compared with Comparative Example 1, the addition of nanoparticles in Example 1 significantly improves the material's temperature and salt resistance, and enhances the polymer's mechanical properties. Compared with Comparative Example 1 and Comparative Example 2, excessively high nanoparticle concentrations can compete with copolymer molecules for adsorption sites or cause over-adsorption, resulting in the copolymer molecular chains being encapsulated or bridged by a large number of nanoparticles. This significantly reduces the effective extension length and accessibility of active functional groups (such as charged groups), severely weakening its core functions of dispersion stability, charge neutralization, or bridging flocculation. Simultaneously, high-concentration nanoparticles drastically increase the total surface area of ​​the material, far exceeding the effective coverage limit of the copolymer. This leads to insufficient charge neutralization on the particle surface or incomplete polymer coating, which in turn induces severe anisotropic aggregation or steric hindrance failure between particles due to van der Waals forces or hydrophobic interactions. This manifests as instability of the dispersed material, abnormally high viscosity, accelerated sedimentation, or poor flocculation (e.g., small, loose flocs with slow sedimentation). Compared with Comparative Example 4, when the copolymer concentration is too high, the material performance tends to decline. This is because excessive copolymer molecular chains may form too many physical or chemical cross-linking points, resulting in an overly dense gel network structure. This highly crowded state significantly reduces the flexibility and swelling capacity of the molecular chains, making the gel brittle, less elastic, and significantly reducing mechanical properties (such as toughness and ductility).

[0113] In summary, the gel material provided by this invention has a short gelation time, excellent mechanical properties, high gel strength, high temperature and salt resistance, high stability, and long effective action time. It can achieve high-strength and effective sealing of water channeling. It also has a simple composition and is easy to prepare and apply. The applicant declares that the above description is merely a specific embodiment of this invention, but the scope of protection of this invention is not limited thereto. Those skilled in the art should understand that any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this invention fall within the scope of protection and disclosure of this invention.

Claims

1. A nanoparticle-reinforced gel material, characterized in that, The composition of the nanoparticle-reinforced gel material, by mass percentage, includes: 1%-2% acrylamide-based copolymer, 0.015%-0.020% crosslinking agent, and 0.10%-0.15% nanoparticles.

2. The nanoparticle-reinforced gel material according to claim 1, characterized in that, The acrylamide-based copolymer includes at least one of the following: acrylamide copolymer containing sulfonic acid groups and / or cyclic amide groups, hydrophobic associative acrylamide copolymer, or zwitterionic acrylamide copolymer.

3. The nanoparticle-reinforced gel material according to claim 2, characterized in that, The acrylamide copolymer containing sulfonic acid groups and / or cyclic amide groups includes at least one of N-vinylpyrrolidone-acrylamide copolymer, 2-acrylamido-2-methylpropanesulfonic acid-acrylamide copolymer, or 2-acrylamido-2-methylpropanesulfonic acid-N-vinylpyrrolidone-acrylamide terpolymer. Preferably, the N-vinylpyrrolidone-acrylamide copolymer comprises a partially hydrolyzed N-vinylpyrrolidone-acrylamide copolymer; Preferably, the degree of hydrolysis of the partially hydrolyzed N-vinylpyrrolidone-acrylamide copolymer is 10%-25%; Preferably, the 2-acrylamido-2-methylpropanesulfonic acid monomer content of the 2-acrylamido-2-methylpropanesulfonic acid-acrylamide copolymer is 25%-40% by mass; Preferably, in the terpolymer of 2-acrylamido-2-methylpropanesulfonic acid-N-vinylpyrrolidone-acrylamide, the monomer content of N-vinylpyrrolidone is 10-30 mol%, and the monomer content of 2-acrylamido-2-methylpropanesulfonic acid is 15-40 mol%.

4. The nanoparticle-reinforced gel material according to claim 2 or 3, characterized in that, The hydrophobically associating acrylamide copolymer includes a hydrophobically associating 2-acrylamido-2-methylpropanesulfonic acid-N-vinylpyrrolidone-acrylamide terpolymer; Preferably, the degree of hydrolysis of the hydrophobically associating acrylamide copolymer is 5%-15%.

5. The nanoparticle-reinforced gel material according to any one of claims 2-4, characterized in that, The zwitterionic acrylamide copolymer includes a betaine-type acrylamide copolymer.

6. The nanoparticle-reinforced gel material according to any one of claims 1-5, characterized in that, The crosslinking agent includes at least one of chromium-based crosslinking agents, zirconium-based crosslinking agents, or phenolic crosslinking agents; Preferably, the chromium-based crosslinking agent comprises chromium acetate and / or chromium malonate; Preferably, the zirconium-based crosslinking agent includes at least one of zirconium oxychloride, zirconium acetate, or zirconium tetrachloride; Preferably, the phenolic crosslinking agent comprises phenolic resin.

7. The nanoparticle-reinforced gel material according to any one of claims 1-6, characterized in that, The average particle size of the nanoparticles is 10-200 nm; Preferably, the specific surface area of ​​the nanoparticles is 60-300 m². 2 / g; Preferably, the nanoparticles include at least one of metal oxide nanoparticles, non-metal oxide nanoparticles, carbon-based nanoparticles, or polymer nanoparticles. Preferably, the metal oxide nanoparticles include at least one of nano-alumina, nano-titanium oxide, or nano-zinc oxide; Preferably, the metal oxide nanoparticles include nano-alumina; Preferably, the non-metallic oxide nanoparticles include nano-silica; Preferably, the carbon-based nanoparticles include graphene and / or carbon nanotubes; Preferably, the polymer nanoparticles comprise nano-polyethyleneimine and / or nano-chitosan.

8. A method for preparing a nanoparticle-reinforced gel material as described in any one of claims 1-7, characterized in that, The preparation method includes: According to the composition of the nanoparticle-reinforced gel material, water is mixed and dispersed with a polymer, a crosslinking agent and nanoparticles to obtain the nanoparticle-reinforced gel material.

9. The preparation method according to claim 8, characterized in that, The mixing method includes stirring; Preferably, the stirring speed is 1000-3000 r / min; Preferably, the mixing temperature is 50-70°C.

10. An application of the nanoparticle-reinforced gel material as described in any one of claims 1-7, characterized in that, The nanoparticle-reinforced gel material is used as a plugging agent for water channeling in natural gas well development.

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