A high-temperature resistant and heat-fading resistant oil well cement admixture material and its preparation method

Abstract

This invention relates to the field of oil well cement admixtures, specifically to a high-temperature resistant and heat-fading-resistant oil well cement admixture material and its preparation method. The cement admixture material comprises a functional additive, a modified carbon nanotube agent, and a fiber material; the mass ratio of the functional additive, modified carbon nanotube agent, and fiber material is (7~11):(4~6):2. The cement admixture material of this invention utilizes the synergistic and balanced interaction of the functional additive, modified carbon nanotube agent, and fiber material to optimize the high-temperature resistance of the product. Under high-temperature conditions, the product exhibits significant anti-permeability and crack resistance, while also demonstrating remarkable heat fading resistance and excellent compressive strength stability.

Description

Technical Field

[0001] This invention relates to the field of oil well cement admixture technology, specifically to a high-temperature resistant and heat-fading-resistant oil well cement admixture material and its preparation method. Background Technology

[0002] Cement is a powdered hydraulic inorganic binder that forms a paste when mixed with water. It can harden in air or water and can firmly bind materials such as sand and stone together. As an important binder, it is widely used in civil engineering, water conservancy, national defense, petroleum or oil well cementing projects. Cement admixtures are chemical substances added during the cement mixing process to improve the performance of cement.

[0003] Existing oil well cement admixtures have poor high-temperature resistance. Under high-temperature conditions, the products are prone to impermeability and crack resistance. At the same time, the products have poor resistance to thermal fading, which can lead to a decrease in compressive strength and limit the efficiency of the products. Based on this, the present invention further improves them. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the purpose of this invention is to provide a high-temperature resistant and heat-fading-resistant oil well cement admixture material and its preparation method, so as to solve the problems mentioned in the background art.

[0005] The present invention solves the technical problem by adopting the following technical solution:

[0006] This invention provides a high-temperature resistant and heat-fading-resistant cement admixture material for oil wells. The cement admixture material comprises a functional additive, a modified carbon nanotube agent, and a fiber material; the mass ratio of the functional additive, the modified carbon nanotube agent, and the fiber material is (7~11):(4~6):2; the preparation method of the functional additive is as follows:

[0007] S01: Stir the mesoporous silica thoroughly in a sufficient amount of sulfuric acid solution, then wash with water, filter and dry. Irradiate the dried mesoporous silica in a proton irradiation chamber for 1 hour at an irradiation power of 350~400W. After irradiation, the irradiated mesoporous silica agent is obtained.

[0008] S02: Prepare a sodium alginate solution with a mass fraction of 10-15%, and mix 3-5 parts of graphene, 2-4 parts of nano calcium carbonate, 2-4 parts of nano titanium dioxide and 7-11 parts of sodium alginate solution thoroughly to obtain the functional material.

[0009] S03: Irradiated mesoporous silica agent and functional material are ball-milled at a weight ratio of (7~11):5, with a ball milling speed of 1500~1700 r / min for 2 hours. After ball milling, the mixture is filtered and dried to obtain the added functional agent. The preparation method of the modified carbon nanotube agent is as follows:

[0010] S11: Stir carbon nanotubes in a sufficient amount of potassium permanganate solution with a mass fraction of 10~15%, then wash with water, filter, and dry. Preheat the dried carbon nanotubes at 60~65℃ for 2 hours to obtain pretreated carbon nanotubes.

[0011] S12: Mix 4-7 parts of silicon carbide whiskers, 3-5 parts of alumina and 10-15 parts of sodium dodecyl sulfate solution evenly to obtain silicon carbide whisker liquid; mix 3-5 parts of silicon micro powder, 2-3 parts of mica powder and 5-9 parts of silicon carbide whisker liquid evenly to obtain whisker-based modified liquid.

[0012] S13: The pretreated carbon nanotubes and the modified liquid are stirred and modified at a weight ratio of 4:(7~11). After stirring, the modified carbon nanotube liquid is obtained.

[0013] S14: The modified carbon nanotube liquid and additives are ball-milled at a weight ratio of (8~11):5, with a ball milling speed of 1000~1500 r / min for 2 hours. After ball milling, the mixture is filtered and dried to obtain the modified carbon nanotube agent.

[0014] Preferably, the fiber material is prepared by mixing basalt fiber, silane liquid and yttrium oxide in a weight ratio of (3~5):7:(2~3), then filtering and drying to obtain the fiber material;

[0015] The silane solution is obtained by mixing silane coupling agent KH550, ethanol aqueous solution and sodium dodecylbenzenesulfonate in a weight ratio of (3~5):(5~7):1.

[0016] The silane solution, prepared by mixing silane coupling agent KH550, sodium dodecylbenzenesulfonate, and an aqueous ethanol solution, can optimize the interfacial relationship between basalt fiber and matrix. In addition, the addition of yttrium oxide further enhances the functionality of the system and improves the performance of the product.

[0017] Preferably, the stirring speed of the blending process is 350~450 r / min, the stirring temperature is 55~60℃, and the stirring time is 1 h; the mass fraction of the ethanol aqueous solution is 75~85%.

[0018] The functional additive uses mesoporous silica as a matrix, which is activated by acid solution and proton irradiation, and improved by ball milling of functional materials. Mesoporous silica has a rich mesoporous structure, which provides excellent loading function for subsequent applications. Graphene, together with nano-calcium carbonate and nano-titanium oxide, works synergistically. The synergistic effect of graphene and nano-titanium oxide, combined with the high temperature resistance and carrier skeleton of mesoporous silica, improves the structural stability of the functional additive at high temperatures. Nano-calcium carbonate fills the mesopores and pores of the cement matrix, and with the mechanical reinforcing effect of graphene, it can improve the compressive strength and crack resistance of the hardened cement. Through the co-mixing improvement of raw materials, the performance effect of the functional additive in the system is enhanced, thereby optimizing the high temperature resistance and heat fading resistance of the product.

[0019] Preferably, the mesoporous silica has a particle size of 70-100 nm and a pore size of 10-20 nm; the sulfuric acid solution has a mass fraction of 15-20%.

[0020] The modified carbon nanotube agent is made by combining carbon nanotubes with potassium permanganate solution and preheating. It is further modified and optimized through stirring of the modified liquid. The silica powder and mica powder in the modified liquid are harmonized, and it is further combined with silicon carbide whisker liquid. The silicon carbide whisker liquid also shows the interaction between silicon carbide whiskers and alumina. The whisker structure of the silicon carbide whiskers, combined with the silica powder, fills the tiny gaps between the silicon carbide whiskers, increasing the system density. The lamellar structure of the mica powder forms a layered barrier in subsequent compounding, slowing down the rapid heat transfer at high temperatures and enhancing interfacial bonding. This ultimately forms a multifunctional modified liquid of "one-dimensional whisker reinforcement + nanoparticle filling + lamellar barrier." The tubular high specific surface area functional structure of the carbon nanotubes further harmonizes and coordinates the components, thereby enhancing the performance of the product system.

[0021] Preferably, the sodium dodecyl sulfate solution has a mass fraction of 8-12%; the stirring speed for the stirring modification treatment is 450-550 r / min, and the stirring time is 1 h.

[0022] Preferably, the preparation method of the additive is as follows:

[0023] Mix 3-5 parts of sodium silicate solution, 2-5 parts of phosphate buffer solution and 3-5 parts of nano-zirconia evenly to obtain a blend. Add 3-4 parts of boron nitride and 2-4 parts of nano-cellulose to 5-7 parts of the blend and mix thoroughly. Then filter and dry to obtain the additive.

[0024] Preferably, the sodium silicate solution has a mass fraction of 8-12%; and the phosphate buffer solution has a pH value of 5.5-6.5.

[0025] Nano-zirconia, with its extremely high melting point (approximately 2715℃) and excellent thermal shock resistance (low coefficient of thermal expansion, capable of buffering stress caused by drastic temperature changes), is a core component for enhancing the high-temperature resistance of additives. It can directly enhance the structural stability of the system at high temperatures. Boron nitride, with its layered hexagonal structure, high temperature resistance, high thermal conductivity, and excellent chemical stability, can form a "thermal conduction pathway" in the additive, helping the cement matrix to dissipate heat quickly at high temperatures, reducing structural damage caused by local overheating, and improving resistance to thermal degradation. Furthermore, by combining it with sodium silicate solution, phosphate buffer solution, and nanocellulose, the additives achieve synergistic effects through the co-mixing and improvement of the raw materials, further enhancing the performance of the product system and improving the product's overall performance.

[0026] This invention also provides a method for preparing a high-temperature resistant and heat-fading-resistant cement admixture material, comprising the following steps:

[0027] Add the functional agent, modified carbon nanotube agent and fiber material to the mixer in sequence and mix evenly to obtain the oil well cement admixture material of the present invention. The mixing speed is 1050~1150 r / min and the mixing time is 1 hour.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The cement admixture material of this invention uses functional agents, modified carbon nanotube agents and fiber materials to work together and blend together. The resulting admixture material can optimize the high temperature resistance of the product. Under high temperature conditions, the product has significant anti-permeability and anti-cracking effects, while also showing obvious resistance to thermal fading and excellent compressive strength stability. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to specific examples. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] This embodiment provides a high-temperature resistant and heat-fading-resistant cement admixture material for oil wells. The cement admixture material includes an additive functional agent, a modified carbon nanotube agent, and a fiber material. The mass ratio of the additive functional agent, the modified carbon nanotube agent, and the fiber material is (7~11):(4~6):2.

[0032] The method for preparing the fiber material in this embodiment is as follows: basalt fiber, silane liquid and yttrium oxide are mixed and stirred in a weight ratio of (3~5):7:(2~3), then filtered and dried to obtain the fiber material;

[0033] The silane solution is obtained by mixing silane coupling agent KH550, ethanol aqueous solution and sodium dodecylbenzenesulfonate in a weight ratio of (3~5):(5~7):1.

[0034] In this embodiment, the stirring speed for the blending and stirring process is 350~450 r / min, the stirring temperature is 55~60℃, and the stirring time is 1 h; the mass fraction of the ethanol aqueous solution is 75~85%.

[0035] The preparation method of the functional additive in this embodiment is as follows:

[0036] S01: Stir the mesoporous silica thoroughly in a sufficient amount of sulfuric acid solution, then wash with water, filter and dry. Irradiate the dried mesoporous silica in a proton irradiation chamber for 1 hour at an irradiation power of 350~400W. After irradiation, the irradiated mesoporous silica agent is obtained.

[0037] S02: Prepare a sodium alginate solution with a mass fraction of 10-15%, and mix 3-5 parts of graphene, 2-4 parts of nano calcium carbonate, 2-4 parts of nano titanium dioxide and 7-11 parts of sodium alginate solution thoroughly to obtain the functional material.

[0038] S03: Irradiated mesoporous silica agent and functional material are ball-milled at a weight ratio of (7~11):5, ball milling speed is 1500~1700 r / min, ball milling for 2 hours, after ball milling is completed, filter and dry to obtain the added functional agent.

[0039] In this embodiment, the mesoporous silica has a particle size of 70-100 nm and a pore size of 10-20 nm; the sulfuric acid solution has a mass fraction of 15-20%.

[0040] The preparation method of the modified carbon nanotube agent in this embodiment is as follows:

[0041] S11: Stir carbon nanotubes in a sufficient amount of potassium permanganate solution with a mass fraction of 10~15%, then wash with water, filter, and dry. Preheat the dried carbon nanotubes at 60~65℃ for 2 hours to obtain pretreated carbon nanotubes.

[0042] S12: Mix 4-7 parts of silicon carbide whiskers, 3-5 parts of alumina and 10-15 parts of sodium dodecyl sulfate solution evenly to obtain silicon carbide whisker liquid; mix 3-5 parts of silicon micro powder, 2-3 parts of mica powder and 5-9 parts of silicon carbide whisker liquid evenly to obtain whisker-based modified liquid.

[0043] S13: The pretreated carbon nanotubes and the modified liquid are stirred and modified at a weight ratio of 4:(7~11). After stirring, the modified carbon nanotube liquid is obtained.

[0044] S14: The modified carbon nanotube liquid and additives are ball-milled at a weight ratio of (8~11):5, with a ball milling speed of 1000~1500 r / min for 2 hours. After ball milling, the mixture is filtered and dried to obtain the modified carbon nanotube agent.

[0045] In this embodiment, the sodium dodecyl sulfate solution has a mass fraction of 8-12%; the stirring speed for the stirring modification treatment is 450-550 r / min, and the stirring time is 1 h.

[0046] The preparation method of the additive in this embodiment is as follows:

[0047] Mix 3-5 parts of sodium silicate solution, 2-5 parts of phosphate buffer solution and 3-5 parts of nano-zirconia evenly to obtain a blend. Add 3-4 parts of boron nitride and 2-4 parts of nano-cellulose to 5-7 parts of the blend and mix thoroughly. Then filter and dry to obtain the additive.

[0048] In this embodiment, the sodium silicate solution has a mass fraction of 8-12%; the phosphate buffer solution has a pH value of 5.5-6.5.

[0049] This embodiment describes a method for preparing a high-temperature resistant and heat-fading-resistant oil well cement admixture material, comprising the following steps:

[0050] Add the functional agent, modified carbon nanotube agent and fiber material to the mixer in sequence and mix evenly to obtain the cement admixture material of the present invention. The mixing speed is 1050~1150 r / min and the mixing time is 1 hour.

[0051] Example 1: A high-temperature resistant and heat-fading resistant cement admixture material for oil wells in this example, the cement admixture material includes functional additives, modified carbon nanotube agents and fiber materials; the mass ratio of the functional additives, modified carbon nanotube agents and fiber materials is 7:4:2.

[0052] The fiber material preparation method of this embodiment is as follows: basalt fiber, silane liquid and yttrium oxide are mixed and stirred in a weight ratio of 3:7:2, then filtered and dried to obtain the fiber material;

[0053] The silane solution is prepared by mixing silane coupling agent KH550, an aqueous ethanol solution, and sodium dodecylbenzenesulfonate in a weight ratio of 3:5:1 until fully stirred.

[0054] In this embodiment, the stirring speed for the blending process is 350 r / min, the stirring temperature is 55℃, and the stirring time is 1 h; the mass fraction of the ethanol aqueous solution is 75%.

[0055] The preparation method of the functional additive in this embodiment is as follows:

[0056] S01: Stir the mesoporous silica in a sufficient amount of sulfuric acid solution until fully stirred, then wash with water, filter and dry. Irradiate the dried mesoporous silica in a proton irradiation chamber for 1 hour at an irradiation power of 350W. After irradiation, the irradiated mesoporous silica agent is obtained.

[0057] S02: Prepare a sodium alginate solution with a mass fraction of 10%, and mix 3 parts graphene, 2 parts nano calcium carbonate, 2 parts nano titanium dioxide and 7 parts sodium alginate solution thoroughly to obtain the functional material.

[0058] S03: Irradiated mesoporous silica agent and functional material are ball-milled at a weight ratio of 7:5 at a speed of 1500 r / min for 2 hours. After ball milling, the mixture is filtered and dried to obtain the added functional agent.

[0059] In this embodiment, the mesoporous silica has a particle size of 70 nm and a pore size of 10 nm; the sulfuric acid solution has a mass fraction of 15%.

[0060] The preparation method of the modified carbon nanotube agent in this embodiment is as follows:

[0061] S11: Stir the carbon nanotubes in a sufficient amount of 10% potassium permanganate solution until homogeneous, then wash with water, filter and dry. Preheat the dried carbon nanotubes at 60°C for 2 hours to obtain pretreated carbon nanotubes.

[0062] S12: Mix 4 parts of silicon carbide whiskers, 3 parts of alumina and 10 parts of sodium dodecyl sulfate solution evenly to obtain silicon carbide whisker liquid; mix 3 parts of silicon micro powder, 2 parts of mica powder and 5 parts of silicon carbide whisker liquid evenly to obtain whisker-based modified liquid.

[0063] S13: The pretreated carbon nanotubes and the modified liquid are stirred and modified at a weight ratio of 4:7. After stirring, the modified carbon nanotube liquid is obtained.

[0064] S14: The modified carbon nanotube liquid and additives were ball-milled at a weight ratio of 8:5 at a speed of 1000 r / min for 2 hours. After ball milling, the mixture was filtered and dried to obtain the modified carbon nanotube agent.

[0065] In this embodiment, the sodium dodecyl sulfate solution has a mass fraction of 8%; the stirring speed for the stirring modification treatment is 450 r / min, and the stirring time is 1 h.

[0066] The preparation method of the additive in this embodiment is as follows:

[0067] Three parts of sodium silicate solution, two parts of phosphate buffer solution and three parts of nano-zirconia were mixed evenly to obtain a blend. Three parts of boron nitride and two parts of nano-cellulose were added to the five parts of the blend and mixed thoroughly. Then the mixture was filtered and dried to obtain the additive.

[0068] In this embodiment, the sodium silicate solution has a mass fraction of 8%; the phosphate buffer solution has a pH value of 5.5.

[0069] This embodiment describes a method for preparing a high-temperature resistant and heat-fading-resistant cement admixture material, comprising the following steps:

[0070] Add the functional agent, modified carbon nanotube agent and fiber material to the mixer in sequence and mix evenly to obtain the oil well cement admixture material of the present invention. The mixing speed is 1050 r / min and the mixing time is 1 hour.

[0071] Example 2: A high-temperature resistant and heat-fading resistant cement admixture material for oil wells in this example, the cement admixture material includes functional additives, modified carbon nanotube agents and fiber materials; the mass ratio of the functional additives, modified carbon nanotube agents and fiber materials is 11:6:2.

[0072] The fiber material preparation method of this embodiment is as follows: basalt fiber, silane liquid and yttrium oxide are mixed and stirred in a weight ratio of 5:7:3, then filtered and dried to obtain the fiber material;

[0073] The silane solution is prepared by mixing silane coupling agent KH550, an aqueous ethanol solution, and sodium dodecylbenzenesulfonate in a weight ratio of 5:7:1 until fully stirred.

[0074] In this embodiment, the stirring speed for the blending process is 450 r / min, the stirring temperature is 60℃, and the stirring time is 1 h; the mass fraction of the ethanol aqueous solution is 85%.

[0075] The preparation method of the functional additive in this embodiment is as follows:

[0076] S01: Stir the mesoporous silica in a sufficient amount of sulfuric acid solution until fully stirred, then wash with water, filter and dry. Irradiate the dried mesoporous silica in a proton irradiation chamber for 1 hour at an irradiation power of 400W. After irradiation, the irradiated mesoporous silica agent is obtained.

[0077] S02: Prepare a sodium alginate solution with a mass fraction of 15%, and mix 5 parts graphene, 4 parts nano calcium carbonate, 4 parts nano titanium dioxide and 11 parts sodium alginate solution thoroughly to obtain the functional material.

[0078] S03: Irradiated mesoporous silica agent and functional material are ball-milled at a weight ratio of 11:5, ball milling speed of 1700 r / min for 2 h. After ball milling, the mixture is filtered and dried to obtain the added functional agent.

[0079] In this embodiment, the mesoporous silica has a particle size of 100 nm and a pore size of 20 nm; the sulfuric acid solution has a mass fraction of 20%.

[0080] The preparation method of the modified carbon nanotube agent in this embodiment is as follows:

[0081] S11: Stir the carbon nanotubes in a sufficient amount of 15% potassium permanganate solution until homogeneous, then wash with water, filter and dry. Preheat the dried carbon nanotubes at 65°C for 2 hours to obtain pretreated carbon nanotubes.

[0082] S12: Mix 7 parts silicon carbide whiskers, 5 parts alumina and 15 parts sodium dodecyl sulfate solution evenly to obtain silicon carbide whisker liquid; mix 5 parts silicon micro powder, 3 parts mica powder and 9 parts silicon carbide whisker liquid evenly to obtain whisker-based modified liquid.

[0083] S13: The pretreated carbon nanotubes and the modified liquid are stirred and modified at a weight ratio of 4:11. After stirring, the modified carbon nanotube liquid is obtained.

[0084] S14: The modified carbon nanotube liquid and additives were ball-milled at a weight ratio of 11:5 at a speed of 1500 r / min for 2 hours. After ball milling, the mixture was filtered and dried to obtain the modified carbon nanotube agent.

[0085] In this embodiment, the sodium dodecyl sulfate solution has a mass fraction of 12%; the stirring speed for the stirring modification treatment is 550 r / min, and the stirring time is 1 h.

[0086] The preparation method of the additive in this embodiment is as follows:

[0087] Five parts of sodium silicate solution, five parts of phosphate buffer solution and five parts of nano-zirconia were mixed evenly to obtain a blend. Four parts of boron nitride and four parts of nano-cellulose were added to the seven parts of the blend and mixed thoroughly. Then the mixture was filtered and dried to obtain the additive.

[0088] In this embodiment, the sodium silicate solution has a mass fraction of 12%; the phosphate buffer solution has a pH value of 6.5.

[0089] This embodiment describes a method for preparing a high-temperature resistant and heat-fading-resistant oil well cement admixture material, comprising the following steps:

[0090] Add the functional agent, modified carbon nanotube agent and fiber material to the mixer in sequence and mix evenly to obtain the cement admixture material of the present invention. The mixing speed is 1150 r / min and the mixing time is 1 hour.

[0091] Example 3: A high-temperature resistant and heat-fading resistant cement admixture material for oil wells in this example, the cement admixture material includes an additive functional agent, a modified carbon nanotube agent, and a fiber material; the mass ratio of the additive functional agent, the modified carbon nanotube agent, and the fiber material is 9:4.5:2.

[0092] The method for preparing the fiber material in this embodiment is as follows: basalt fiber, silane liquid and yttrium oxide are mixed and stirred in a weight ratio of 4:7:2.5, then filtered and dried to obtain the fiber material;

[0093] The silane solution is prepared by mixing silane coupling agent KH550, an aqueous ethanol solution, and sodium dodecylbenzenesulfonate in a weight ratio of 4:6:1 until fully stirred.

[0094] In this embodiment, the stirring speed for the blending process is 400 r / min, the stirring temperature is 57.5℃, and the stirring time is 1 h; the mass fraction of the ethanol aqueous solution is 80%.

[0095] The preparation method of the functional additive in this embodiment is as follows:

[0096] S01: Stir the mesoporous silica thoroughly in a sufficient amount of sulfuric acid solution, then wash with water, filter, and dry. Irradiate the dried mesoporous silica in a proton irradiation chamber for 1 hour at an irradiation power of 375W. After irradiation, the irradiated mesoporous silica agent is obtained.

[0097] S02: Prepare a sodium alginate solution with a mass fraction of 12.5%, and mix 4 parts graphene, 3 parts nano calcium carbonate, 3 parts nano titanium dioxide and 9 parts sodium alginate solution thoroughly to obtain the functional material.

[0098] S03: Irradiated mesoporous silica agent and functional material are ball-milled at a weight ratio of 9:5 at a speed of 1600 r / min for 2 hours. After ball milling, the mixture is filtered and dried to obtain the added functional agent.

[0099] In this embodiment, the mesoporous silica has a particle size of 85 nm and a pore size of 15 nm; the sulfuric acid solution has a mass fraction of 17.5%.

[0100] The preparation method of the modified carbon nanotube agent in this embodiment is as follows:

[0101] S11: Stir the carbon nanotubes in a sufficient amount of 12.5% ​​potassium permanganate solution until homogeneous, then wash with water, filter, and dry. Preheat the dried carbon nanotubes at 62℃ for 2 hours to obtain pretreated carbon nanotubes.

[0102] S12: Mix 5.5 parts of silicon carbide whiskers, 4 parts of alumina and 12.5 parts of sodium dodecyl sulfate solution evenly to obtain silicon carbide whisker liquid; mix 4 parts of silicon micro powder, 2.5 parts of mica powder and 7 parts of silicon carbide whisker liquid evenly to obtain whisker-based modified liquid.

[0103] S13: The pretreated carbon nanotubes and whisker-based modified liquid are mixed and modified at a weight ratio of 4:9. After the mixing is completed, the modified carbon nanotube liquid is obtained.

[0104] S14: The modified carbon nanotube liquid and additives were ball-milled at a weight ratio of 9:5 at a speed of 1250 r / min for 2 hours. After ball milling, the mixture was filtered and dried to obtain the modified carbon nanotube agent.

[0105] In this embodiment, the sodium dodecyl sulfate solution has a mass fraction of 10%; the stirring speed for the stirring modification treatment is 500 r / min, and the stirring time is 1 h.

[0106] The preparation method of the additive in this embodiment is as follows:

[0107] Four parts of sodium silicate solution, 3.5 parts of phosphate buffer solution and four parts of nano-zirconia were mixed evenly to obtain a blend. Three parts of boron nitride and three parts of nano-cellulose were added to the six parts of the blend and mixed thoroughly. Then the mixture was filtered and dried to obtain the additive.

[0108] In this embodiment, the sodium silicate solution has a mass fraction of 10%; the phosphate buffer solution has a pH value of 6.0.

[0109] This embodiment describes a method for preparing a high-temperature resistant and heat-fading-resistant oil well cement admixture material, comprising the following steps:

[0110] Add the functional agent, modified carbon nanotube agent and fiber material to the mixer in sequence and mix evenly to obtain the cement admixture material of the present invention. The mixing speed is 1100 r / min and the mixing time is 1 hour.

[0111] Comparative Example 1.

[0112] Unlike Example 3, no fiber material was added.

[0113] Comparative Example 2.

[0114] Unlike Example 3, basalt fiber and yttrium oxide were not added in the preparation method of the fiber material.

[0115] Comparative Example 3.

[0116] Unlike Example 3, no functional agents were added.

[0117] Comparative Example 4.

[0118] Unlike Example 3, no functional material was added during the preparation of the added functional agent.

[0119] Comparative Example 5.

[0120] Unlike Example 3, no nano-calcium carbonate or nano-titanium oxide was added to the functional material.

[0121] Comparative Example 6.

[0122] Unlike Example 3, no irradiated mesoporous silica agent was added during the preparation of the added functional agent.

[0123] Comparative Example 7.

[0124] Unlike Example 3, no modified carbon nanotube agent was added.

[0125] Comparative Example 8.

[0126] Unlike Example 3, no modified carbon nanotube liquid was added in the preparation of the modified carbon nanotube agent.

[0127] Comparative Example 9.

[0128] Unlike Example 3, no pretreated carbon nanotubes were added in the preparation of the modified carbon nanotube liquid.

[0129] Comparative Example 10.

[0130] Unlike Example 3, no silicon micropowder or mica powder was added in the preparation of the whisker-based modified liquid.

[0131] Comparative Example 11.

[0132] Unlike Example 3, no silicon carbide whiskers or alumina were added in the preparation of the whisker-based modified liquid.

[0133] Comparative Example 12.

[0134] Unlike Example 3, no additives were added during the preparation of the modified carbon nanotube agent.

[0135] The products of Examples 1-3 and Comparative Examples 1-12 were added to conventional cement at a dosage of 3% to prepare the test products. The impermeability and crack resistance of the test products were tested under high temperature conditions. At the same time, the compressive strength performance of the test products was tested under thermal decay conditions. The performance test results are shown in Table 1 below. Table 1 is the comprehensive performance test result table of the products.

[0136] Table 1:

[0137]

[0138] As can be seen from Comparative Examples 1-12 and Examples 1-3;

[0139] The product in Example 3 exhibits excellent resistance to seepage and cracking under high temperature conditions, while maintaining excellent compressive strength under thermal degradation conditions, demonstrating significant thermal degradation stability.

[0140] As can be seen from Comparative Examples 1-12 and Example 3, the performance of the products tends to deteriorate when no fiber material is added to the product, and no basalt fiber and yttrium oxide are added in the preparation method of the fiber material.

[0141] The performance of the product deteriorates significantly when neither functional agent nor modified carbon nanotube agent is added. The combined effect of the two agents results in the most significant performance improvement.

[0142] In the preparation of functional agents, no functional materials are added, no nano-calcium carbonate or nano-titanium oxide is added to the functional materials, and no irradiated mesoporous silica agent is added. The performance of the products all tends to deteriorate to varying degrees. The functional agents obtained by the specific method of this invention have the most significant performance effect.

[0143] In the preparation of modified carbon nanotube agents, no modified carbon nanotube liquid is added; in the preparation of modified carbon nanotube liquid, no pretreated carbon nanotubes are added; in the preparation of whisker-based modified liquid, no silicon micropowder or mica powder is added; in the preparation of whisker-based modified liquid, no silicon carbide whiskers or alumina are added; and in the preparation of modified carbon nanotube agents, no additives are added. The performance of the products in all these cases tends to deteriorate to varying degrees. Only the modified carbon nanotube agent prepared using the specific method of this invention, with whisker-based modified liquid and additives, exhibits the most significant performance improvement. Other methods are not as effective as those of this invention. Furthermore, the performance deterioration is also more pronounced in the preparation of modified carbon nanotube agents without additives, while the addition of additives significantly enhances the product's performance.

[0144] This invention further explores the product's performance through the preparation of additives;

[0145] Experimental Example 1.

[0146] Same as Example 3, except that boron nitride was not added to the additives.

[0147] Experimental Example 2.

[0148] Same as Example 3, except that nanocellulose was not added to the additives.

[0149] Experimental Example 3.

[0150] Same as Example 3, except that nano-zirconia was not added to the additives.

[0151] Experimental Example 4.

[0152] Same as Example 3, except that sodium silicate solution was not added to the additives and water was used instead of phosphate buffer solution.

[0153] The present invention further tested the performance of the products of Experimental Examples 1-4. The performance test results are shown in Table 2 below. Table 2 shows the effect of the preparation of additives on the performance of the products.

[0154] Table 2:

[0155]

[0156] As can be seen from Experiments 1-4, the absence of nano-zirconia in the additives resulted in the most significant deterioration in product performance among the factors affecting additive preparation. The absence of boron nitride, nano-cellulose, sodium silicate solution, and the substitution of water for phosphate buffer all led to a deterioration in product performance. Only the additives prepared using the specific method of this invention exhibited the most significant performance improvement. In the preparation of the additives, all raw materials are indispensable; only the specific raw material ratios of this invention are used. Using other raw material ratios does not yield the same significant results as this invention.

[0157] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0158] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A high-temperature resistant and heat-fading-resistant oil well cement admixture material, characterized in that, The cement admixture material includes functional additives, modified carbon nanotube agents, and fiber materials; the mass ratio of the functional additives, modified carbon nanotube agents, and fiber materials is (7~11):(4~6):2; The preparation method of the added functional agent is as follows: S01: Stir the mesoporous silica thoroughly in a sufficient amount of sulfuric acid solution, then wash with water, filter and dry. Irradiate the dried mesoporous silica in a proton irradiation chamber for 1 hour at an irradiation power of 350~400W. After irradiation, the irradiated mesoporous silica agent is obtained. S02: Prepare a sodium alginate solution with a mass fraction of 10-15%, and mix 3-5 parts of graphene, 2-4 parts of nano calcium carbonate, 2-4 parts of nano titanium dioxide and 7-11 parts of sodium alginate solution thoroughly to obtain the functional material. S03: Irradiated mesoporous silica agent and functional material are ball-milled at a weight ratio of (7~11):5, ball milling speed of 1500~1700 r / min for 2 hours. After ball milling, the mixture is filtered and dried to obtain the added functional agent. The preparation method of the modified carbon nanotube agent is as follows: S11: Stir carbon nanotubes in a sufficient amount of potassium permanganate solution with a mass fraction of 10~15%, then wash with water, filter, and dry. Preheat the dried carbon nanotubes at 60~65℃ for 2 hours to obtain pretreated carbon nanotubes. S12: Mix 4-7 parts of silicon carbide whiskers, 3-5 parts of alumina and 10-15 parts of sodium dodecyl sulfate solution evenly to obtain silicon carbide whisker liquid; mix 3-5 parts of silicon micro powder, 2-3 parts of mica powder and 5-9 parts of silicon carbide whisker liquid evenly to obtain whisker-based modified liquid. S13: The pretreated carbon nanotubes and whisker-based modified liquid are mixed and modified at a weight ratio of 4:(7~11). After mixing, the modified carbon nanotube liquid is obtained. S14: The modified carbon nanotube liquid and additives are ball-milled at a weight ratio of (8~11):5, with a ball milling speed of 1000~1500 r / min for 2 hours. After ball milling, the mixture is filtered and dried to obtain the modified carbon nanotube agent.

2. The high-temperature resistant and heat-fading-resistant oil well cement admixture material according to claim 1, characterized in that, The fiber material is prepared by mixing basalt fiber, silane liquid and yttrium oxide in a weight ratio of (3~5):7:(2~3), then filtering and drying to obtain the fiber material. The silane solution is obtained by mixing silane coupling agent KH550, ethanol aqueous solution and sodium dodecylbenzenesulfonate in a weight ratio of (3~5):(5~7):

1.

3. The high-temperature resistant and heat-fading-resistant oil well cement admixture material according to claim 2, characterized in that, The stirring speed for the blending process is 350~450 r / min, the stirring temperature is 55~60℃, and the stirring time is 1 h; the mass fraction of the ethanol aqueous solution is 75~85%.

4. The high-temperature resistant and heat-fading-resistant oil well cement admixture material according to claim 1, characterized in that, The mesoporous silica has a particle size of 70-100 nm and a pore size of 10-20 nm; the sulfuric acid solution has a mass fraction of 15-20%.

5. The high-temperature resistant and heat-fading-resistant oil well cement admixture material according to claim 4, characterized in that, The sodium dodecyl sulfate solution has a mass fraction of 8-12%; the stirring speed for the stirring modification treatment is 450-550 r / min, and the stirring time is 1 h.

6. The high-temperature resistant and heat-fading-resistant oil well cement admixture material according to claim 1, characterized in that, The preparation method of the additive is as follows: Mix 3-5 parts of sodium silicate solution, 2-5 parts of phosphate buffer solution and 3-5 parts of nano-zirconia evenly to obtain a blend. Add 3-4 parts of boron nitride and 2-4 parts of nano-cellulose to 5-7 parts of the blend and mix thoroughly. Then filter and dry to obtain the additive.

7. The high-temperature resistant and heat-fading-resistant oil well cement admixture material according to claim 6, characterized in that, The sodium silicate solution has a mass fraction of 8-12%; the phosphate buffer solution has a pH value of 5.5-6.

5.

8. The preparation method of a high-temperature resistant and heat-fading-resistant oil well cement admixture material as described in any one of claims 1 to 7, characterized in that, Includes the following steps: Add the functional agent, modified carbon nanotube agent and fiber material to the mixer in sequence and mix evenly to obtain the oil well cement admixture material. The mixing speed is 1050~1150 r / min and the mixing time is 1 hour.

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