Modified non-metallic material, method for preparing same, and use thereof
By modifying the end face of non-metallic materials, the problem of poor dispersion of high thermal conductivity materials in cement was solved, thereby improving the uniformity and stability of cement slurry, meeting the needs of geothermal energy development, and reducing preparation costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2025-01-02
- Publication Date
- 2026-07-03
AI Technical Summary
Existing high thermal conductivity materials have poor dispersibility in cement, and the amount added is limited, which affects the uniformity and stability of cement slurry. Moreover, the preparation process is complex and costly, making it difficult to meet the needs of geothermal energy development.
Modified non-metallic materials are prepared by modifying their end faces and reacting alkaline substances and oxidants in a suspension. This process maintains the continuity of the material's lamellar structure, improves its dispersibility and addition amount in cement, and reduces preparation costs.
Modified non-metallic materials exhibit good dispersibility in cement slurry, improving thermal conductivity, uniformity, and stability of the slurry, while reducing preparation costs, making them suitable for large-scale applications.
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Figure CN122324801A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of geothermal energy development, specifically to a modified non-metallic material, its preparation method, and its application. Background Technology
[0002] In modern technological development, the thermal conductivity of materials is an important research direction. High thermal conductivity materials, due to their excellent thermal conductivity, are widely used in various fields requiring efficient heat transfer, such as electronic equipment, energy storage and transmission equipment, and aerospace equipment. Among these, the development of geothermal energy also has a huge demand for high thermal conductivity materials. Geothermal well cementing is a common and crucial step in geothermal energy development. Its core is to use cement slurry to effectively isolate the geothermal well from the underground rock formation to ensure a stable output of geothermal energy. However, traditional cement slurry materials have poor thermal conductivity, which cannot meet the needs of geothermal energy development. To solve this problem, existing solutions mainly involve adding high thermal conductivity materials, such as flake graphite, silicon carbide, and boron nitride, to improve the thermal conductivity of the cement slurry. However, these high thermal conductivity materials have poor dispersibility in cement, which not only affects the uniformity and stability of the cement slurry but also limits the improvement of its thermal conductivity. Secondly, the amount of existing high thermal conductivity materials added to cement is limited, which restricts further improvements in their thermal conductivity. Existing processes for modifying high thermal conductivity materials are complex, costly, and involve significant stress fluctuations. The introduced functional groups disrupt the original planar structure and properties of the material, limiting its large-scale application. Therefore, improving the dispersibility of high thermal conductivity materials in cement, increasing their dosage, and reducing their preparation costs are crucial technological challenges. Summary of the Invention
[0003] The purpose of this invention is to overcome the problems of poor dispersibility of high thermal conductivity materials in cement and the impact of high addition amount on the rheological properties of cement slurry in the existing technology, and to provide a modified non-metallic material with the advantages of good dispersibility in cement and no reduction in the rheological properties of cement slurry even with high addition amount.
[0004] To achieve the above objectives, the first aspect of the present invention provides a modified non-metallic material, wherein the modified non-metallic material has an oxygen content of 0.5-1.5 wt%, a zeta potential of -30 mV to -15 mV, and a tablet contact angle of 30°-55°.
[0005] The interlayer spacing ratio between the modified non-metallic material and the unmodified non-metallic material is 1:0.8-1.1.
[0006] A second aspect of the present invention provides a method for preparing a modified non-metallic material, the method comprising:
[0007] (1) A suspension is obtained by mixing a non-metallic substrate, an alkaline substance and a suspending agent;
[0008] (2) Add an oxidant to the suspension obtained in step (1) to react, and then separate the solid and liquid.
[0009] A third aspect of the present invention provides a modified nonmetallic material prepared by the above-described method.
[0010] A fourth aspect of the present invention provides a thermally conductive cement slurry, the high thermal conductivity cement slurry comprising: the above-mentioned modified non-metallic material.
[0011] The fifth aspect of the present invention provides the application of the modified nonmetallic material described above in cementing.
[0012] Through the above technical solution, the present invention can achieve at least the following beneficial effects:
[0013] (1) The modified non-metallic material of the present invention has good dispersibility in cement slurry, thereby providing thermal conductivity to cement while improving the uniformity and stability of cement slurry.
[0014] (2) Even when the amount of the modified non-metallic material added to the cement slurry is higher than the conventional amount, it will not affect the rheological properties of the cement slurry, thereby effectively improving the thermal conductivity of the cement slurry and meeting the needs of geothermal energy development.
[0015] (3) The preparation process of the modified non-metallic material of the present invention is simple, and the raw materials and reaction conditions are relatively mild, which can greatly reduce its preparation cost and facilitate its large-scale application. Attached Figure Description
[0016] Figure 1 This is a comparison diagram of the contact angle of the modified non-metallic material prepared in Example 1 before and after modification.
[0017] Figure 2 This is a comparison of the infrared absorption spectra of two batches of the modified non-metallic material (BO01 and BO02) prepared in Example 1 with the unmodified non-metallic material (graphite).
[0018] Figure 3 These are XRD diffraction comparison images of two batches of the modified non-metallic material (BO01 and BO02) prepared in Example 1 and the unmodified non-metallic material (graphite). Detailed Implementation
[0019] The endpoints and any values of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of the various ranges, the endpoint values of the various ranges and individual point values, and individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.
[0020] The first aspect of the present invention provides a modified non-metallic material, wherein the oxygen content of the modified non-metallic material is 0.5-1.5 wt%, the zeta potential is -30 mV to -15 mV, and the tablet contact angle is 30°-55°;
[0021] The interlayer spacing ratio between the modified non-metallic material and the unmodified non-metallic material is 1:0.8-1.1.
[0022] The inventors of this invention discovered during their research that by selectively modifying the end faces of non-metallic materials, the resulting end-face modified non-metallic materials can not only significantly improve the dispersibility of thermally conductive materials in cement slurry, but also increase their addition amount in cement slurry. "End face" refers to the surface perpendicular to the layered structure in a crystal structure.
[0023] In this invention, preferably, the oxygen content of the modified non-metallic material is 0.8-1.4 wt% (for example, it can be any two values formed by 0.8 wt%, 0.9 wt%, 1.0 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, and 1.4 wt%, or a value within that range), the Zeta potential is -28 mV to -20 mV (for example, it can be any two values formed by -28 mV, -27 mV, -26 mV, -25 mV, -24 mV, -23 mV, -22 mV, -21 mV, and -20 mV), and the tablet contact angle is 30°-40° (for example, it can be any two values formed by 30°, 31°, 32°, 33°, 34°, 35°, 36°, 37°, 38°, 39°, and 40°).
[0024] In this invention, preferably, the interlayer spacing ratio between the modified non-metallic material and the unmodified non-metallic material is 1:0.9-1 (for example, it can be any two ratios from 1:0.9, 1:0.91, 1:0.92, 1:0.93, 1:0.94, 1:0.95, 1:0.96, 1:0.97, 1:0.98, 1:0.99, 1:1 forming a range or ratio within that range).
[0025] In this invention, the modified non-metallic material has a layered structure composed of non-metallic elements other than oxygen, and the oxygen element in the modified non-metallic material is distributed on the end face of the layered structure.
[0026] In this invention, the interlayer spacing of the modified non-metallic material can be 0.3-0.4 nm, preferably 0.33-0.36 nm.
[0027] In this invention, the modified non-metallic material can be a material based on conventional thermally conductive materials (thermal conductivity of 50-6000 W / m·K). Preferably, the modified non-metallic material is a modified carbon-based material and / or a modified nitride material, preferably at least one of modified graphite, modified graphene, modified carbon nanotubes, modified silicon carbide, modified carbon nitride, modified silicon nitride, and modified aluminum nitride. It is understood that the modified non-metallic material is an end-face modified non-metallic material.
[0028] In this invention, preferably, the average particle size of the modified non-metallic material is 10-200 μm, more preferably 15-150 μm, and even more preferably 20-100 μm (for example, it can be any two values formed by 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, and 100 μm, or a value within that range).
[0029] In this invention, preferably, there is no special limitation on the morphology of the modified non-metallic material. For example, it can be at least one of scaly, earthy, and spherical shapes, more preferably scaly.
[0030] A second aspect of the present invention provides a method for preparing a modified non-metallic material, the method comprising:
[0031] (1) A suspension is obtained by mixing a non-metallic substrate, an alkaline substance and a suspending agent;
[0032] (2) Add an oxidant to the suspension obtained in step (1) to react, and then separate the solid and liquid.
[0033] It is understood that the method for preparing modified non-metallic materials described in this invention, by combining alkali and oxidant while the reaction system is in suspension, allows for highly selective oxidation of the end face (edge of the conjugate plane) of the non-metallic substrate without disrupting the continuity of the non-metallic substrate's layered structure, thereby achieving regional selective modification of the non-metallic substrate.
[0034] In this invention, the non-metallic substrate can be a conventional thermally conductive material (thermal conductivity of 50-6000 W / m·K). Preferably, the non-metallic substrate is selected from carbon-based materials and / or nitride materials, and more preferably at least one of graphite, graphene, carbon nanotubes, silicon carbide, carbon nitride, silicon nitride, and aluminum nitride. The interlayer spacing of the modified non-metallic material of this invention is not substantially changed compared to the non-metallic substrate (unmodified non-metallic material). Taking graphite as an example, the interlayer spacing of graphite modified according to the method of this invention is still around 0.34 nm.
[0035] In this invention, preferably, the average particle size of the non-metallic substrate is 10-200 μm, more preferably 15-150 μm, and even more preferably 20-100 μm (for example, it can be any two values from 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, forming a range and values within that range).
[0036] In this invention, preferably, there is no special limitation on the morphology of the non-metallic substrate. For example, it can be at least one of flake-like, earth-like, and spherical shapes, and more preferably flake-like.
[0037] In a preferred embodiment of the present invention, the particle size of the non-metallic substrate can be obtained by grinding. The grinding method can be as follows: placing grinding balls and non-metallic substrate in a grinding jar, grinding at a rotational speed of 50-150 revolutions per minute for 10-30 minutes, and processing 1-10 times.
[0038] In this invention, the alkaline substance can be a common organic base or a common inorganic base. Preferably, the alkaline substance is selected from at least one of sodium hydroxide, potassium hydroxide, ammonia, sodium carbonate, potassium carbonate, triethylamine, triethylenediamine, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazabicyclo[4.3.0]non-5-ene, 4-dimethylaminopyridine, pyridine, N-methylmorpholine, tetramethylethylenediamine, tetramethylguanidine, potassium tert-butoxide, sodium tert-butoxide, and lithium diisopropylamino.
[0039] In a preferred embodiment of the present invention, the alkaline substance is a mixed alkali, wherein the mixed alkali is a mixture of sodium hydroxide, potassium hydroxide, potassium tert-butoxide, and sodium tert-butoxide.
[0040] In a preferred embodiment of the present invention, the molar ratio of sodium hydroxide, potassium hydroxide, potassium tert-butoxide and sodium tert-butoxide in the mixed alkali is 0.5-3:1:0.25-0.75:0.25-0.75, more preferably 1-2:1:0.4-0.6:0.4-0.6.
[0041] In this invention, preferably, the suspending agent can be a commonly used suspending agent in the art, for example, water.
[0042] In this invention, preferably, in step (1), the amount of suspending agent is such that the concentration of alkaline substance in the suspension is 1-10 mol / L, more preferably 2-5 mol / L, and even more preferably 2.8-4.2 mol / L (for example, it can be any two values from 2.8 mol / L, 3 mol / L, 3.2 mol / L, 3.4 mol / L, 3.6 mol / L, 3.8 mol / L, 4 mol / L, 4.2 mol / L, or any value within that range).
[0043] In this invention, the oxidant can be a substance commonly used in the art that can oxidize non-metallic substrates (thermally conductive non-metallic materials). Preferably, the oxidant is selected from oxidizing elements, peroxides, perborates, and organic oxidants. More preferably, it is at least one of pyridinium chlorochromate, Na2O2, K2O2, MgO2, CaO2, BaO2, H2O2, tert-butyl hydroperoxide, sodium hypochlorite, peracetic acid, sodium percarbonate, sodium perborate, potassium perborate, bromine, and iodine.
[0044] In this invention, preferably, the amount of oxidant used is such that the concentration of oxidant in the reaction system is 1.5-10 wt%, more preferably 2.5-8 wt%, and even more preferably 3-6 wt% (for example, it can be any two values formed by 3 wt%, 3.2 wt%, 3.5 wt%, 3.8 wt%, 4 wt%, 4.3 wt%, 4.5 wt%, 4.7 wt%, 5 wt%, 5.2 wt%, 5.5 wt%, 5.7 wt%, 6 wt%, and values within the range).
[0045] In this invention, preferably, the reaction conditions include: a reaction temperature of 20-40℃, more preferably 25-35℃ (for example, it can be any two values from 25℃, 26℃, 27℃, 28℃, 29℃, 30℃, 31℃, 32℃, 33℃, 34℃, 35℃, or any value within that range), and a reaction time of 20-30h, more preferably 22-25h (for example, it can be any two values from 22h, 22.5h, 23h, 23.5h, 24h, 24.5h, 25h, or any value within that range).
[0046] In this invention, preferably, the amount of alkaline substance used relative to 10g of non-metallic substrate is 0.5-3mol, more preferably 0.8-2.5mol (for example, it can be any two values from 0.8mol, 0.9mol, 1mol, 1.2mol, 1.5mol, 1.8mol, 2mol, 2.3mol, 2.5mol, forming a range and values within the range).
[0047] In this invention, the method may further include solid-liquid separation, washing, and drying.
[0048] It is understood that this invention, through mild oxidants and reaction conditions, combines strong and weak alkaline substances in an alkaline environment. Simultaneously, the reaction system is in a suspension, which enables highly selective oxidation of the end face (edge of the conjugate plane) of the non-metallic substrate without disrupting the continuity of the non-metallic substrate's layered structure, thereby achieving regional selective modification of the non-metallic substrate.
[0049] A third aspect of the present invention provides a modified nonmetallic material prepared by the above-described method.
[0050] A fourth aspect of the present invention provides a thermally conductive cement slurry, the high thermal conductivity cement slurry comprising: the above-mentioned modified non-metallic material (as a thermally conductive material).
[0051] In this invention, preferably, the thermally conductive cement slurry further includes: cement, a water loss reducing agent, an early strength agent, and a dispersant.
[0052] In this invention, preferably, there is no particular limitation on the type of cement, as long as it can be formulated into a thermally conductive cement slurry. For example, it can be oil well cement, and more preferably, it can be G-grade high sulfate-resistant oil well cement.
[0053] In this invention, preferably, the early strength agent is selected from sulfate early strength agents and / or halogen salt early strength agents, more preferably at least one of sodium sulfate, calcium chloride, calcium sulfate and potassium sulfate.
[0054] In this invention, preferably, the dispersant can be a commonly used dispersant in the art, for example, it can be selected from at least one of polycarboxylic acid dispersants, fatty alcohol polyoxyethylene ether dispersants and lignin sulfonate dispersants.
[0055] In this invention, the water loss reducing agent can be a common water loss reducing agent in the art. Preferably, the water loss reducing agent is at least one of polyacrylate (e.g., sodium polyacrylate and / or potassium polyacrylate), polyvinyl alcohol (PVA), cellulose derivative (e.g., methylcellulose and / or hydroxypropyl methylcellulose), silicate (e.g., sodium silicate), anionic surfactant (sodium dodecyl sulfate and / or sodium dodecylbenzene sulfonate), and nonionic surfactant (e.g., polyoxyethylene ether).
[0056] In this invention, preferably, the mass ratio of the cement, modified non-metallic material, water loss reducing agent, early strength agent and dispersant can be 100:5-10:2-5:0.1-1:0.1-1, more preferably 100:10-12:3-4:0.2-0.8:0.2-0.5.
[0057] The fifth aspect of the present invention provides the application of the modified nonmetallic material described above in cementing.
[0058] The present invention will be described in detail below through examples. In the following examples, DZJ-Y fluid loss reducing agent is a commercially available product of Dezhou Continental Shelf Petroleum Engineering Technology Co., Ltd., with the brand name DZJ-Y; G-grade high sulfate-resistant oil well cement is a commercially available product of Shandong Chongzheng Special Cement Co., Ltd.; and polycarboxylate dispersant is a commercially available product of China Petroleum & Chemical Corporation Petroleum Engineering Technology Research Institute, with the brand name 90-L.
[0059] The average particle size parameter of the material was measured by the laser particle size analyzer (FRITSCH method);
[0060] The interlayer spacing was tested using XRD crystal diffraction peaks; the zeta potential was tested using a nano-laser particle size analyzer (ZEN3600); the tablet contact angle was tested using a full-range contact angle meter (DSA100); and the oxygen content was tested using thermogravimetric analysis (the product was calcined at high temperature in an inert atmosphere, and the oxygen content was deduced from the mass change curve).
[0061] Example 1
[0062] Prepare 200g of flake graphite. Open the grinding jar lid, place the grinding balls and the material to be treated inside, set the rotation speed to 120 rpm in the Rotational speed window, the processing time to 15 min in the Time window, and the number of repetitions to 4 in the Repetition window. This yields flake graphite with an average particle size of 30 μm.
[0063] 10g of the above-treated flake graphite with an average particle size of 30μm was dispersed in 0.5L of a mixed alkaline solution (water was used as the suspending agent, resulting in a concentration of 3.5mol / L of the mixed alkaline solution in the suspension) to obtain a suspension. The mixed alkaline solution consisted of sodium hydroxide, potassium hydroxide, potassium tert-butoxide, and sodium tert-butoxide in a molar ratio of 3:1:0.5:0.5.
[0064] An oxidant (tert-butyl hydroperoxide and sodium peroxide in a molar ratio of 3:1) was added to the suspension in a 30°C water bath. The concentration of the oxidant in the reaction system was 3 wt%, and the reaction was stirred for 24 h.
[0065] The resulting suspension was filtered, washed, and dried to obtain the modified non-metallic material product.
[0066] The comparison diagram of the contact angle of the modified nonmetal before and after tableting is shown in the figure below. Figure 1 As shown in the figure (left: non-metallic material before modification, right: non-metallic material after modification); the comparison of infrared absorption spectra of two batches of modified non-metallic materials (BO01 and BO02) with unmodified non-metallic materials (graphite) is shown in the figure. Figure 2 As shown; XRD diffraction comparison diagrams of two batches of modified non-metallic materials (BO01 and BO02) and unmodified non-metallic materials (graphite) are shown below. Figure 3 As shown in Table 1, the interlayer spacing and other parameters of the modified non-metallic material products are as follows.
[0067] Example 2
[0068] Prepare 200g of flake graphite. Open the grinding jar lid, place the grinding balls and the material to be treated inside, set the rotation speed to 120 rpm in the Rotational speed window, the processing time to 15 min in the Time window, and the number of repetitions to 4 in the Repetition window. This yields flake graphite with an average particle size of 30 μm.
[0069] 10g of the above-treated flake graphite with an average particle size of 30μm was dispersed in 0.3L of a mixed alkaline solution (water was used as the suspending agent, resulting in a concentration of 2.8mol / L of the mixed alkaline solution in the suspension) to obtain a suspension. The mixed alkaline solution consisted of sodium hydroxide, potassium hydroxide, potassium tert-butoxide, and sodium tert-butoxide in a molar ratio of 1:1:0.4:0.4.
[0070] An oxidant (peracetic acid) was added to the suspension in a 35°C water bath. The concentration of the oxidant in the reaction system was 6 wt%, and the reaction was stirred for 25 h.
[0071] The resulting suspension was filtered, washed, and dried to obtain the modified non-metallic material product. The interlayer spacing and other parameters of the modified non-metallic material product are shown in Table 1.
[0072] Example 3
[0073] Prepare 200g of flake graphite. Open the grinding jar lid, place the grinding balls and the material to be treated inside, set the rotation speed to 120 rpm in the Rotational speed window, the processing time to 15 min in the Time window, and the number of repetitions to 4 in the Repetition window. This yields flake graphite with an average particle size of 30 μm.
[0074] 10 g of the above-treated flake graphite with an average particle size of 30 μm was dispersed in 0.45 L of a mixed alkaline solution (water was used as the suspending agent, resulting in a concentration of 4.2 mol / L of the mixed alkaline solution in the suspension) to obtain a suspension. The mixed alkaline solution consisted of sodium hydroxide, potassium hydroxide, potassium tert-butoxide, and sodium tert-butoxide in a molar ratio of 2:1:0.6:0.6.
[0075] A mild oxidant (sodium hypochlorite) was added to the suspension in a 25°C water bath. The concentration of the oxidant in the reaction system was 4.5 wt%, and the reaction was stirred for 22 h.
[0076] The resulting suspension was filtered, washed, and dried to obtain the modified non-metallic material product. The interlayer spacing and other parameters of the modified non-metallic material product are shown in Table 1.
[0077] Example 4
[0078] The modified non-metallic material product was prepared according to the method of Example 1, except that the mixed alkali was sodium hydroxide and potassium hydroxide in a molar ratio of 3:2.
[0079] Example 5
[0080] Modified nonmetallic materials were prepared according to the method in Example 1, except that the Time window was set to 10 min during the grinding process, and the number of repetitions was set to 2. Flake graphite with an average particle size of 140 μm was obtained.
[0081] Example 6
[0082] The modified nonmetallic material was prepared according to the method of Example 1, except that the concentration of the oxidant in the reaction system was 2 wt%.
[0083] Example 7
[0084] The modified nonmetallic material was prepared according to the method of Example 1, except that the concentration of the oxidant in the reaction system was 8 wt%.
[0085] Example 8
[0086] The modified non-metallic material was prepared according to the method of Example 1, except that the suspending agent was water, and the use of water made the concentration of the mixed alkaline solution in the suspension 8 mol / L. The mixed alkaline was sodium hydroxide, potassium hydroxide, potassium tert-butoxide and sodium tert-butoxide, with a molar ratio of 4:1:1.5:1.5.
[0087] Comparative Example 1
[0088] Modified nonmetallic materials were prepared according to the method in Example 1, except that flake graphite, oxidant and mixed alkaline solution were directly mixed in a 30°C water bath and stirred for 24 hours.
[0089] Comparative Example 2
[0090] Prepare 200g of flake graphite. Open the grinding jar lid, place the grinding balls and the material to be treated inside, set the rotation speed to 120 rpm in the Rotational speed window, the processing time to 15 min in the Time window, and the number of repetitions to 4 in the Repetition window. This yields flake graphite with an average particle size of 30 μm.
[0091] Take 10g of the above-treated flake graphite with an average particle size of 30μm and add it to 460mL of concentrated sulfuric acid (98wt%). After stirring evenly, slowly add 30g of potassium permanganate, maintain the temperature at 3℃, and continue stirring for 2h. Then add 920mL of deionized water, control the temperature at 30℃, and stir for 2h. Finally, add hydrogen peroxide (30wt%) until the solution turns bright yellow. Centrifuge the mixture, remove the supernatant, and wash it three times alternately with deionized water and dilute hydrochloric acid (1wt%). Finally, dry it to obtain graphite oxide.
[0092] Table 1
[0093] As shown in Table 1, the interlayer spacing ratio of the modified graphite prepared in Examples 1-8 to the control group (flake graphite) is in the range of 1:0.94-1.06. The pressing contact angle of the control group (flake graphite) is 62.4°, while that of the modified graphite prepared in Examples 1-8 is 34°-49.6°. The pressing contact angles of the graphite oxide prepared in Comparative Examples 1 and 2 are 58.4° and 56.1°, respectively. The Zeta potential of the control group (flake graphite) is -3.4mV, while that of the modified graphite prepared in Examples 1-8 is -17.71mV to -30.12mV. The oxygen content of the control group (flake graphite) is <0.1wt%, while that of the modified graphite prepared in Examples 1-8 is 0.66-1.45wt%. Therefore, it can be seen that the modification of the graphite does not occur between the layers, but rather at the end face. Scanning electron microscopy revealed that the modification process did not damage the original planar structure of the material.
[0094] Test Example 1
[0095]
[0096] The end-face modified high thermal conductivity material products prepared in the above embodiments and comparative examples were formulated into a thermally conductive cement slurry, the specific formula of which is as follows:
[0097] Formula A: 100 parts by weight of Grade G high sulfate-resistant oil well cement + 3.5 parts by weight of DZJ-Y fluid loss reducer + 1 part by weight of calcium sulfate + 0.4 parts by weight of polycarboxylic acid dispersant 90-L + 10 parts by weight of the modified non-metallic material prepared in Example 1 + 51 parts by weight of water.
[0098] Cement slurry was prepared according to the dosage of each substance in formula A. The difference was that the modified non-metallic material prepared in Example 1 was replaced with the modified non-metallic material prepared in the examples and comparative examples in turn, so as to obtain cement slurry of formula BJ.
[0099] Formula K: 100 parts by weight of G-grade high sulfate-resistant oil well cement + 3.5 parts by weight of DZJ-Y fluid loss reducer + 1 part by weight of calcium sulfate + 0.4 parts by weight of polycarboxylate dispersant 90-L + 10 parts by weight of high thermal conductivity material (flake graphite with an average particle size of 30μm) + 51 parts by weight of water.
[0100] Formula L: 100 parts by weight of G-grade high sulfate-resistant oil well cement + 3.5 parts by weight of DZJ-Y fluid loss reducer + 1 part by weight of calcium sulfate + 0.4 parts by weight of polycarboxylate dispersant 90-L + 15 parts by weight of the modified non-metallic material prepared in Example 1 + 51 parts by weight of water.
[0101] Formula M: 100 parts by weight of Grade G high sulfate-resistant oil well cement + 3.5 parts by weight of DZJ-Y fluid loss reducer + 1 part by weight of calcium sulfate + 0.4 parts by weight of polycarboxylate dispersant 90-L + 15 parts by weight of high thermal conductivity material (flake graphite with an average particle size of 30μm) + 51 parts by weight of water.
[0102] After the above formula was prepared, slurry stability tests and six-speed viscosity tests were conducted. The density difference between the upper and lower layers and the consistency coefficient of the slurry were calculated after 15 minutes of natural settling. Then, after 24 hours at 90℃ × 10MPa, the thermal conductivity of the cement paste was tested using the hot wire method. The test data are shown in Table 2.
[0103] Table 2
[0104]
[0105] Table 2 shows that the cement slurry prepared by formula AH has a density difference between 0.03 and 0.05 g / mL, demonstrating excellent settling stability. The consistency coefficient of the cement slurry prepared by formula AH is between 0.37 and 0.69, indicating excellent rheological properties. Formulas K and L reflect that, with increased amounts of modified graphite and graphite, the modified graphite cement slurry system maintains good performance, while the performance of the unmodified graphite cement slurry system deteriorates. Furthermore, the rheological properties of the cement slurry system indicate that the modified non-metallic materials must be uniformly dispersed in the slurry; poor dispersion will lead to severe thickening and deterioration of rheological properties.
[0106] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.
Claims
1. A modified non-metallic material, characterized in that, The modified non-metallic material has an oxygen content of 0.5-1.5 wt%, a zeta potential of -30 mV to -15 mV, and a tablet contact angle of 30°-55°. The interlayer spacing ratio between the modified non-metallic material and the unmodified non-metallic material is 1:0.8-1.
1.
2. The modified non-metallic material of claim 1, wherein, The modified non-metallic material has an oxygen content of 0.8-1.4 wt%, a zeta potential of -28 mV to -20 mV, and a tablet contact angle of 30°-40°. And / or, the modified non-metallic material has a lamellar structure composed of non-metallic elements other than oxygen, the oxygen element in the modified non-metallic material is distributed on the end face of the lamellar structure, and the interlayer spacing ratio of the modified non-metallic material to the unmodified non-metallic material is 1:0.9-1; And / or, the interlayer spacing of the modified non-metallic material is 0.3-0.4 nm, preferably 0.33-0.36 nm.
3. The modified non-metallic material according to claim 1 or 2, wherein, The modified non-metallic material is a modified carbon-based material and / or a modified nitride material, preferably at least one of modified graphite, modified graphene, modified carbon nanotubes, modified silicon carbide, modified carbon nitride, modified silicon nitride, and modified aluminum nitride.
4. The modified non-metallic material according to claim 1 or 2, wherein, The average particle size of the modified non-metallic material is 10-200 μm, preferably 15-150 μm, and more preferably 20-100 μm; And / or, the morphology of the modified nonmetallic material is at least one of scaly, earthy, and spherical.
5. A method for producing a modified non-metallic material, characterized by, The method includes: (1) A suspension is obtained by mixing a non-metallic substrate, an alkaline substance and a suspending agent; (2) Add an oxidant to the suspension obtained in step (1) to react, and then separate the solid and liquid.
6. The method of claim 5, wherein, The non-metallic substrate is selected from carbon-based materials and / or nitride materials, preferably at least one of graphite, graphene, carbon nanotubes, silicon carbide, carbon nitride, silicon nitride and aluminum nitride; Preferably, the average particle size of the non-metallic substrate is 10-200 μm, more preferably 15-150 μm, and even more preferably 20-100 μm; Preferably, the morphology of the non-metallic substrate is at least one of scaly, earthy, and spherical shapes.
7. The method of claim 5 or 6, wherein, The alkaline substance is selected from at least one of sodium hydroxide, potassium hydroxide, ammonia, sodium carbonate, potassium carbonate, triethylamine, triethylenediamine, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazabicyclo[4.3.0]non-5-ene, 4-dimethylaminopyridine, pyridine, N-methylmorpholine, tetramethylethylenediamine, tetramethylguanidine, potassium tert-butoxide, sodium tert-butoxide, and lithium diisopropylamino. Preferably, the alkaline substance is a mixed alkali, wherein the mixed alkali is a mixture of sodium hydroxide, potassium hydroxide, potassium tert-butoxide, and sodium tert-butoxide; Preferably, the molar ratio of sodium hydroxide, potassium hydroxide, potassium tert-butoxide, and sodium tert-butoxide in the mixed alkali is 0.5-3:1:0.25-0.75:0.25-0.75, and more preferably 1-2:1:0.4-0.6:0.4-0.6; Preferably, in step (1), the amount of suspending agent used is such that the concentration of alkaline substance in the suspension is 1-10 mol / L, more preferably 2-5 mol / L, and even more preferably 2.8-4.2 mol / L.
8. The method of claim 5 or 6, wherein, The oxidant is selected from oxidizing elements, peroxides, perborates and organic oxidants, preferably at least one of pyridinium chlorochromate, Na2O2, K2O2, MgO2, CaO2, BaO2, H2O2, tert-butyl hydroperoxide, sodium hypochlorite, peracetic acid, sodium percarbonate, sodium perborate, potassium perborate, bromine and iodine. Preferably, the amount of oxidant used is such that the concentration of oxidant in the reaction system is 1.5-10 wt%, more preferably 2.5-8 wt%, and even more preferably 3-6 wt%.
9. The method of claim 5 or 6, wherein, The reaction conditions include: a reaction temperature of 20-40℃, preferably 25-35℃, and a reaction time of 20-30h, preferably 22-25h; And / or, relative to 10g of non-metallic substrate, the amount of the alkaline substance is 0.5-3mol, preferably 0.8-2.5mol.
10. The modified nonmetallic material prepared by the method according to any one of claims 5-9.
11. A thermally conductive cementitious slurry, characterized in that, The thermally conductive cement slurry comprises: the modified non-metallic material according to any one of claims 1-4 and 10.
12. The thermally conductive cement slurry of claim 11, wherein, The thermally conductive cement slurry also includes: cement, water loss reducing agent, early strength agent and dispersant; Preferably, the early strength agent is selected from sulfate-based early strength agents and / or halogen-based early strength agents, and more preferably from at least one of sodium sulfate, calcium chloride, calcium sulfate and potassium sulfate.
13. The thermally conductive cement slurry of claims 11 or 12, wherein, The mass ratio of cement, modified non-metallic materials, water loss reducing agent, early strength agent and dispersant is 100:5-10:2-5:0.1-1:0.1-1, preferably 100:10-12:3-4:0.2-0.8:0.2-0.
5.
14. The application of the modified nonmetallic material according to any one of claims 1-4 and 10 in cementing.