A multi-dimensional nanometer-based functional material for oil well cement

Abstract

The application discloses a multi-dimensional nanometer-based functional material for oil well cement, which comprises a dispersion of two-dimensional nanometer materials, a dispersion of one-dimensional nanometer materials and a dispersion of zero-dimensional nanometer materials. The mass ratio of the dispersion of two-dimensional nanometer materials, the dispersion of one-dimensional nanometer materials and the dispersion of zero-dimensional nanometer materials is 5:3:2. The solid content of the dispersion of two-dimensional nanometer materials is 15% to 20%. The solid content of the dispersion of one-dimensional nanometer materials is 5% to 10%. The solid content of the dispersion of zero-dimensional nanometer materials is 15% to 20%. The application combines the nanometer materials of different components in three dimensions together according to engineering requirements, and makes full use of the structural characteristics of various dimensions to play a role in promoting hydration, nucleation and improving mechanical properties, so that the material simultaneously shows excellent functions of accelerating coagulation, preventing channeling and enhancing strength, and shows the characteristics of one dose with multiple effects.

Description

Technical Field

[0001] This application relates to the field of oilfield cementing, and more particularly to a multidimensional nano-based functional material for oil well cement. Background Technology

[0002] As exploration and development deepen, the operating environment becomes increasingly complex, and operating costs are gradually decreasing, posing a severe challenge to cementing technology. How to minimize costs while solving engineering problems is a hot topic in future new materials research and development. Traditional materials, due to their inherent limitations, struggle to meet these requirements. Nanomaterials, with their scale falling between the microscopic and macroscopic realms, exhibit many unique effects distinct from traditional materials, demonstrating enormous application potential in numerous industries.

[0003] The research and application of nanomaterials in oil and gas well cementing is still in its early stages, with most studies conducted indoors and few applied in the field. The main problems and difficulties limiting their application in oil and gas well cementing are as follows: (1) Nanomaterials are extremely small in size, making them easy to agglomerate and difficult to disperse, resulting in the ineffective "nano-effect" and minimal effect after being added to cement slurry. (2) Due to their large specific surface area, nanomaterials often cause severe thickening when added to cement slurry, limiting their dosage and effectiveness. (3) Many nanomaterials have complex production processes and often only perform one function, resulting in low cost and low efficiency, which limits their application under the low-cost strategy of oil and gas well engineering. Therefore, it is of great significance to develop multifunctional nanomaterials with low cost and good comprehensive performance suitable for oil and gas well cementing. Summary of the Invention

[0004] This application provides a multi-dimensional nano-based functional material for oil well cement, which can be used in oil and gas well cementing.

[0005] The following technical solution was adopted in this application:

[0006] This application provides a multidimensional nano-based functional material for oil well cement, comprising dispersions of two-dimensional nanomaterials, one-dimensional nanomaterials, and zero-dimensional nanomaterials. The mass ratio of the two-dimensional, one-dimensional, and zero-dimensional nanomaterial dispersions is 5:3:2. The solid content of the two-dimensional nanomaterial dispersion is 15%–20%. The solid content of the one-dimensional nanomaterial dispersion is 5%–10%. The solid content of the zero-dimensional nanomaterial dispersion is 15%–20%.

[0007] Furthermore, the dispersion of the two-dimensional nanomaterials includes a dispersion of nano-calcium silicate and a dispersion of nano-sheet alumina. The mass ratio of nano-calcium silicate to nano-sheet alumina is 3:1. The size of the nano-calcium silicate is 50–100 nm. The thickness of the nano-sheet alumina is 60–80 nm. The dispersion of nano-calcium silicate is synthesized by solution precipitation method, and the raw materials and their mass parts used in the synthesis are: 20–50 parts of calcium nitrate, 10–30 parts of calcium chloride, 20–50 parts of sodium metasilicate, 10–30 parts of polycarboxylic acid dispersant, and 5–10 parts of sulfonated aldehyde-ketone condensate dispersant.

[0008] Furthermore, the one-dimensional nanomaterials include inorganic nanofiber materials and organic nanofiber materials. The inorganic nanofiber materials are selected from one or a mixture of several of silicon nanowires, zinc oxide nanowires, silicon carbide, and carbon nanotubes. The organic nanofiber materials are selected from one or a mixture of several of nanocellulose and polyvinyl alcohol nanofibers. The mass ratio of inorganic nanofiber materials to organic nanofiber materials is 1:1. The diameter of the one-dimensional nanomaterials is 20–60 nm. The one-dimensional nanomaterials in the dispersion are treated with a silane coupling agent and a polycarboxylic acid dispersant, with a mass ratio of silane coupling agent to polycarboxylic acid dispersant of 2:1.

[0009] Furthermore, the zero-dimensional nanomaterials are selected from one or a mixture of several of nanospherical silica and nanospherical alumina. The particle size of the zero-dimensional nanomaterials is 10–30 nm. The zero-dimensional nanomaterials in the dispersion are surface-treated with amide copolymers containing amino and carboxyl groups. The relative molecular weight of the amide copolymers containing amino and carboxyl groups is 120,000–150,000, and the molecular weight distribution index is 2.0–2.2.

[0010] Furthermore, the polycarboxylic acid dispersant has a relative molecular weight of 60,000 to 100,000 and a molecular weight distribution index of 1.5 to 1.7.

[0011] Compared with the prior art, this application has the following beneficial effects:

[0012] 1. Nanomaterials with different dimensions move in different directions, thus exhibiting different properties. This application combines three types of nanomaterials with different compositions in different dimensions in combination with engineering needs. By utilizing the structural characteristics of each dimension, the material can fully play its role in promoting hydration, nucleation and improving mechanical properties, so that the material can simultaneously exhibit excellent functions such as promoting coagulation, preventing cross-linking and strengthening, thus exhibiting the characteristics of multiple effects in one dose.

[0013] 2. Based on the characteristics of the material, multiple surface treatment modifications are adopted, such as polycarboxylic acid dispersants, sulfonated aldehyde-ketone condensate dispersants, silane coupling agents, and multi-branched amide copolymers containing amino and carboxyl groups, to avoid the aggregation of nanoparticles, thereby giving full play to the nano effect and significantly increasing the material performance.

[0014] 3. By introducing substances with significant steric hindrance effects, such as polycarboxylic acid, sulfonated aldehyde-ketone condensates, and carboxyl groups—multi-branched amide copolymers containing amino and carboxyl groups—significant drag reduction is achieved, thereby avoiding the thickening problem of nanomaterials in cement slurry and demonstrating an improved rheological effect.

[0015] 4. By combining one-dimensional inorganic nanomaterials and one-dimensional organic nanomaterials, the respective properties of each are fully utilized, significantly improving the mechanical properties of cement stone.

[0016] 5. Multidimensional nano-based functional materials have simple preparation processes, low costs, and are easy to industrialize. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating the fabrication process of the multidimensional nano-based functional material products in this application. Detailed Implementation

[0018] The technical methods in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0019] This application provides a multidimensional nano-based functional material for oil well cement, which is composed of dispersions of three different dimensions of nanomaterials: two-dimensional nanomaterials, one-dimensional nanomaterials, and zero-dimensional nanomaterials. The mass ratio of the two-dimensional, one-dimensional, and zero-dimensional nanomaterial dispersions is 5:3:2.

[0020] The dispersion of two-dimensional nanomaterials is a composite of dispersions of two two-dimensional nanomaterials: a dispersion of nano-calcium silicate and a dispersion of nano-sheet alumina. The solid content of the dispersion of two-dimensional nanomaterials is 15%–20%, such as 15%, 18%, or 20%. The mass ratio of nano-calcium silicate to nano-sheet alumina is 3:1. The nanoscale size of the nano-calcium silicate is 50–100 nm, such as 50 nm, 80 nm, or 100 nm. The sheet thickness of the nano-sheet alumina is 60–80 nm, such as 60 nm, 70 nm, or 80 nm.

[0021] Specifically, the dispersion of nano-calcium silicate is a thin-film-like dispersion of nano-calcium silicate, synthesized by solution precipitation method. The raw materials and their mass parts used in the synthesis are: calcium nitrate 20-50 parts, such as 20 parts, 30 parts, or 50 parts; calcium chloride 10-30 parts, such as 10 parts, 20 parts, or 30 parts; sodium metasilicate 20-50 parts, such as 20 parts, 30 parts, or 50 parts; polycarboxylic acid dispersant 10-30 parts, such as 10 parts, 20 parts, or 30 parts; and sulfonated aldehyde-ketone condensate dispersant 5-10 parts, such as 5 parts, 8 parts, or 10 parts. Specifically, the preparation method of the above-mentioned dispersion of nano-calcium silicate includes the following steps:

[0022] (1) Provide the following raw materials in parts by weight: 20-50 parts calcium nitrate, 10-30 parts calcium chloride, 20-50 parts sodium metasilicate, 10-30 parts polycarboxylic acid dispersant, and 5-10 parts sulfonated aldehyde ketone condensate dispersant.

[0023] In the above steps, the polycarboxylic acid dispersant is composed of polyether grafted with a certain side chain length using methacrylic acid as the main chain. The relative molecular weight of the polycarboxylic acid dispersant is 60,000 to 100,000, and the molecular weight distribution index is 1.5 to 1.7. The sulfonated aldehyde-ketone condensate dispersant is a conventional dispersant for oil well cement, but it can also be other commercially available products, such as CF40S. This application does not limit the specific products used.

[0024] (2) Add an appropriate amount of distilled water to a beaker, weigh out the polycarboxylic acid dispersant and the sulfonated aldehyde ketone condensate dispersant, mix them evenly, and pour them into a clean three-necked flask. Turn on the stirrer and maintain the speed at 300±10 r / min, such as 290 r / min, 300 r / min, or 310 r / min. Then, add the pre-prepared mixed solution of calcium nitrate and calcium chloride and the sodium metasilicate solution to two constant pressure dropping funnels respectively. Then, turn on the heating device and purge with nitrogen for protection. When the system temperature rises to 25℃, open the two dropping funnels simultaneously to initiate the reaction. During the reaction, use sodium hydroxide solution or nitric acid solution to control the pH value of the system at 11-13, such as pH=11, pH=12, or pH=13. Maintain the temperature at 25-40℃, such as 25℃, 30℃, or 40℃, and react at a constant temperature for 6-10 hours, such as 6 hours, 8 hours, or 10 hours. Then, a thin film-like nano-calcium silicate dispersion is obtained.

[0025] One-dimensional nanomaterials are composed of a blend of inorganic and organic nanofiber materials. The inorganic nanofiber materials are selected from one or more of silicon nanowires, zinc oxide nanowires, silicon carbide, and carbon nanotubes, or a mixture thereof. For example, the inorganic nanofiber materials may be selected from silicon nanowires or a mixture of silicon carbide and carbon nanotubes. The organic nanofiber materials are selected from one or more of nanocellulose and polyvinyl alcohol nanofibers, or a mixture of nanocellulose and polyvinyl alcohol nanofibers. The mass ratio of inorganic to organic nanofiber materials is 1:1. The diameters of the one-dimensional nanomaterials are all 20–60 nm, such as 20 nm, 40 nm, and 60 nm.

[0026] The one-dimensional nanomaterials in the dispersion are treated with a silane coupling agent and a polycarboxylic acid dispersant, with a mass ratio of silane coupling agent to polycarboxylic acid dispersant of 2:1. The silane coupling agent can be prepared using existing processes or other commercially available products, such as KH550; this application does not limit its use. The requirements for the polycarboxylic acid dispersant are the same as above and will not be repeated here. The solid content of the one-dimensional nanomaterial dispersion is 5-10%, such as 5%, 8%, or 10%.

[0027] Zero-dimensional nanomaterials are selected from one or a mixture of nano-spherical silica and nano-spherical alumina. For example, zero-dimensional nanomaterials are selected from nano-spherical silica, or from a mixture of nano-spherical silica and nano-spherical alumina. The particle size of zero-dimensional nanomaterials is 10–30 nm, such as 10 nm, 20 nm, and 30 nm.

[0028] The zero-dimensional nanomaterials in the dispersion are surface-treated with amino- and carboxyl-containing amide copolymers. These amide copolymers have a relative molecular weight of 120,000–150,000 and a molecular weight distribution index of 2.0–2.2. Specifically, the amino- and carboxyl-containing amide copolymers are multi-branched amide copolymers containing amino and carboxyl groups, which can be prepared using existing processes. The solid content of the zero-dimensional nanomaterial dispersion is 15%–20%, such as 15%, 18%, or 20%.

[0029] The multi-dimensional nano-based functional material for oil well cement in this application belongs to the cement admixtures used in the field of oilfield cementing. It can not only improve the rheological properties of cement slurry while significantly shortening the setting time and reducing the probability of crossflow, but also significantly increase the early and late strength of cement stone and improve the toughness of cement stone, thus having multiple functions in one agent.

[0030] See Figure 1The embodiments of this application provide a method for preparing the above-mentioned multidimensional nano-based functional material for oil well cement, comprising the following steps:

[0031] A thin-film dispersion of nano-calcium silicate was prepared. This dispersion was then placed in an ultrasonic device and maintained for 20 minutes. Following this, a dispersion of nano-alumina was added at a mass ratio of 3:1 (calcium silicate to nano-alumina flakes) to obtain a two-dimensional nanomaterial dispersion. Then, a one-dimensional nanomaterial dispersion and a zero-dimensional nanomaterial dispersion were gradually added to the two-dimensional nanomaterial dispersion at a mass ratio of 5:3:2 (two-dimensional, one-dimensional, and zero-dimensional). After maintaining the dispersion with ultrasound for 30–60 minutes, a multi-dimensional nano-based functional material product was obtained.

[0032] The multi-dimensional nano-based functional material for oil well cement prepared in this application does not thicken the cement slurry, and can significantly shorten the setting time and static gelation transition time, thereby significantly increasing the cement slurry's anti-channeling ability and the cement stone's resistance to damage.

[0033] In summary, this application addresses the problem of the ineffective utilization of nanomaterials' nano-effects in cement slurry through two main approaches. Firstly, it fully leverages the synergistic effect of composite materials. This is achieved by organically combining three dimensions of nanomaterials, utilizing their unique properties, to maximize their synergistic effect. Secondly, it organically combines inorganic and organic nanomaterials to leverage their combined synergistic effect. Secondly, it avoids nanomaterial aggregation by combining various surface modification methods with ultrasonic dispersion, thereby maximizing the nano-effects of the nanomaterials. Through these methods, the nano-effects of nanomaterials in cement slurry are fully realized.

[0034] Because nanomaterials have a large specific surface area, they easily cause thickening of the system. To address the thickening problem of traditional nanomaterials in cement slurry, this application uses polycarboxylic acid, sulfonated aldehyde-ketone condensates, and substances with significant steric hindrance effects (containing carboxyl groups) – multi-branched amide copolymers containing amino and carboxyl groups – to modify the nanomaterials. These substances enhance the nano-effect while also effectively reducing drag in the cement slurry, thus avoiding the thickening problem of nanomaterials in cement slurry without affecting other properties.

[0035] To address the challenges of complex production, limited functionality, and high costs associated with nanomaterials, this application employs a solution precipitation method and composite modification to prepare multi-dimensional nano-based functional materials for oil well cement. This process is simple, easily industrialized, and cost-effective. By combining nanomaterials of different dimensions and compositions according to engineering requirements, and leveraging their unique characteristics, a multi-functional approach is achieved, realizing the high efficiency of nanomaterials and laying the foundation for their industrial application.

[0036] The following detailed description is provided with reference to specific embodiments:

[0037] Example 1

[0038] Add an appropriate amount of distilled water to a beaker, weigh out 30 parts of polycarboxylic acid dispersant and 5 parts of sulfonated aldehyde ketone condensate dispersant, mix well, and pour into a clean three-necked flask. Turn on the stirrer and maintain a speed of 300±10 r / min. Weigh out 20 parts of calcium nitrate and 30 parts of calcium chloride and dissolve them in an appropriate amount of distilled water. Weigh out 50 parts of sodium metasilicate and dissolve them in an appropriate amount of distilled water. Then, add the prepared mixed solution of calcium nitrate and calcium chloride and the sodium metasilicate solution to two constant pressure dropping funnels respectively. Turn on the heating device and purge with nitrogen for protection. When the system temperature rises to 25℃, open both dropping funnels simultaneously to initiate the reaction. During the reaction, use sodium hydroxide solution or nitric acid solution to control the pH value of the system at 10-13, maintain the temperature at 25-40℃, and react at a constant temperature for 6-10 hours to obtain a thin film-like dispersion of nano-calcium silicate.

[0039] The above-mentioned dispersion of nano-calcium silicate was placed in an ultrasonic device, and the ultrasonic treatment was maintained for 20 minutes. Then, nano-alumina dispersion was added at a mass ratio of 3:1 between nano-calcium silicate and nano-alumina to obtain a dispersion of two-dimensional nanomaterials with a solid content of 15%.

[0040] A dispersion of one-dimensional nanomaterials (made of silicon carbide, nanocellulose, silane coupling agent, polycarboxylic acid dispersant, and water, with a mass ratio of 1:1 for silicon carbide and 2:1 for silane coupling agent and polycarboxylic acid dispersant, and surface-treated with silane coupling agent and polycarboxylic acid dispersant) and a dispersion of zero-dimensional nanomaterials (made of nanospherical silica, multi-branched amide copolymer containing amino and carboxyl groups, and water, with surface-treated nanospherical silica by multi-branched amide copolymer containing amino and carboxyl groups) with a solid content of 5:3:2 were gradually added to a dispersion of two-dimensional nanomaterials, a dispersion of one-dimensional nanomaterials, and a dispersion of zero-dimensional nanomaterials. After ultrasonication for 30-60 minutes, a multi-dimensional nano-based functional material product was obtained and marked as sample #1.

[0041] Example 2

[0042] Add an appropriate amount of distilled water to a beaker, weigh out 20 parts of polycarboxylic acid dispersant and 10 parts of sulfonated aldehyde ketone condensate dispersant, mix well, and pour into a clean three-necked flask. Turn on the stirrer and maintain a speed of 300±10 r / min. Weigh out 35 parts of calcium nitrate and 10 parts of calcium chloride and dissolve them in an appropriate amount of distilled water. Weigh out 35 parts of sodium metasilicate and dissolve them in an appropriate amount of distilled water. Then, add the prepared mixed solution of calcium nitrate and calcium chloride and the sodium metasilicate solution to two constant pressure dropping funnels respectively. Turn on the heating device and purge with nitrogen for protection. When the system temperature rises to 25℃, open both dropping funnels simultaneously to initiate the reaction. During the reaction, use sodium hydroxide solution or nitric acid solution to control the pH value of the system at 10-13, and maintain the temperature at 25-40℃. After reacting at a constant temperature for 6-10 hours, a thin film of nano-calcium silicate dispersion is obtained.

[0043] The above-mentioned dispersion of nano-calcium silicate was placed in an ultrasonic device, and the ultrasonic treatment was maintained for 20 minutes. Then, nano-alumina dispersion was added at a mass ratio of 3:1 between nano-calcium silicate and nano-alumina to obtain a dispersion of two-dimensional nanomaterials with a solid content of 18%.

[0044] A dispersion of one-dimensional nanomaterials (composed of carbon nanotubes, nanocellulose, silane coupling agent, polycarboxylic acid dispersant, and water, with a mass ratio of 1:1 for carbon nanotubes and 2:1 for silane coupling agent and polycarboxylic acid dispersant, and surface-treated with silane coupling agent and polycarboxylic acid dispersant) and a dispersion of zero-dimensional nanomaterials (composed of nano-spherical alumina, multi-branched amide copolymer containing amino and carboxyl groups, and water, with surface-treated nano-spherical alumina with multi-branched amide copolymer containing amino and carboxyl groups) with a solid content of 18% were gradually added to a dispersion of two-dimensional nanomaterials at a mass ratio of 5:3:2. After sonication for 30-60 minutes, a multi-dimensional nano-based functional material product was obtained and labeled as sample #2.

[0045] Example 3

[0046] Add an appropriate amount of distilled water to a beaker, weigh out 10 parts of polycarboxylic acid dispersant and 10 parts of sulfonated aldehyde ketone condensate dispersant, mix them evenly, and pour them into a clean three-necked flask. Turn on the stirrer and maintain the speed at 300±10 r / min. Weigh out 50 parts of calcium nitrate and 10 parts of calcium chloride and dissolve them in an appropriate amount of distilled water. Weigh out 30 parts of sodium metasilicate and dissolve them in an appropriate amount of distilled water. Then add the prepared mixed solution of calcium nitrate and calcium chloride and the sodium metasilicate solution to two constant pressure dropping funnels respectively. Turn on the heating device and purge with nitrogen for protection. When the system temperature rises to 25℃, open the two dropping funnels simultaneously to initiate the reaction. During the reaction, use sodium hydroxide solution or nitric acid solution to control the pH value of the system at 10-13, and maintain the temperature at 25-40℃. After reacting at a constant temperature for 6-10 hours, a thin film of nano-calcium silicate dispersion is obtained.

[0047] The above-mentioned dispersion of nano-calcium silicate was placed in an ultrasonic device, and the ultrasonic treatment was maintained for 20 minutes. Then, nano-alumina dispersion was added at a mass ratio of 3:1 between nano-calcium silicate and nano-alumina to obtain a dispersion of two-dimensional nanomaterials with a solid content of 20%.

[0048] A dispersion of one-dimensional nanomaterials (composed of silicon nanowires, polyvinyl alcohol nanofibers, silane coupling agent, polycarboxylic acid dispersant, and water, with a mass ratio of 1:1 for silicon nanowires and 2:1 for polycarboxylic acid dispersant, and surface-treated by silane coupling agent and polycarboxylic acid dispersant) and a dispersion of zero-dimensional nanomaterials (composed of nano-spherical alumina, multi-branched amide copolymer containing amino and carboxyl groups, and water, with surface-treated by multi-branched amide copolymer containing amino and carboxyl groups) with a solid content of 10% and a mass ratio of 5:3:2 for one-dimensional nanomaterials and zero-dimensional nanomaterials were gradually added to the dispersion of two-dimensional nanomaterials, in a mass ratio of 5:3:2. The dispersion of one-dimensional nanomaterials and 20% was then added to the dispersion of zero-dimensional nanomaterials.

[0049] Test case

[0050] Performance evaluation of multidimensional nano-based functional material samples

[0051] The samples were evaluated according to the test methods specified in GB / T 19139-2012 "Test Methods for Oil Well Cement". Table 1 shows the evaluation of the influence of multi-dimensional nano-based functional material samples on the rheology and thickening time of cement slurry; Table 2 shows the evaluation of the influence of multi-dimensional nano-based functional material samples on the static gelation transition time of cement slurry; Table 3 shows the evaluation of the influence of multi-dimensional nano-based functional material samples on the strength development of cement paste; and Table 4 shows the evaluation of the influence of multi-dimensional nano-based functional material samples on the mechanical properties of cement paste.

[0052] (1) The effects of multidimensional nano-based functional materials samples 1#, 2#, and 3# on the rheological properties and thickening time of cement paste were experimentally tested and compared with commonly used calcium chloride-based accelerators. The rheological test temperature was 20℃, and the thickening time test was conducted at 30℃ and 50℃. The basic formulation at 30℃ was: Grade G cement + multidimensional nano-based functional material sample or calcium chloride + water (maintaining a liquid-to-solid ratio of 0.44). Considering practical applications, the formulation containing a water loss reducer was selected at 50℃: Grade G cement + multidimensional nano-based functional material sample or calcium chloride + 4% AMPS polymer-based water loss reducer + water (maintaining a liquid-to-solid ratio of 0.44). The test results are shown in Table 1.

[0053] Table 1. Effects of multidimensional nano-based functional material samples on cement slurry rheology and thickening time.

[0054]

[0055] The experimental results above show that the multi-dimensional nano-based functional materials samples 1#, 2#, and 3# can significantly shorten the thickening time of cement slurry and improve its rheological properties while accelerating setting, overcoming the thickening problem of conventional accelerators such as calcium chloride. Furthermore, conventional accelerators, due to limitations in thickening dosage, are unable to effectively shorten the thickening time of cement slurry with AMPS polymer-based water loss reducers as the main agent. The product of this application can effectively shorten the thickening time without thickening.

[0056] (2) Static gelation transition time is an important indicator of the cement slurry's ability to prevent cross-linking, and conventional materials are unlikely to effectively shorten the static gelation transition time. The effects of multi-dimensional nano-based functional materials samples 1#, 2#, and 3# on the static gelation transition time of cement slurry were tested at a temperature of 30℃. The basic cement slurry formula was: Grade G cement + multi-dimensional nano-based functional material sample + water (maintaining a liquid-to-solid ratio of 0.44). The test results are shown in Table 2.

[0057] Table 2. Effects of multidimensional nano-based functional material samples on the static setting time of cement paste.

[0058]

[0059] The experimental results above show that the multidimensional nano-based functional materials 1#, 2# and 3# can significantly shorten the static gelation transition time of cement slurry, with a shortening rate of up to 84.0%, thereby significantly increasing the anti-channeling performance of cement slurry.

[0060] (3) The effects of multidimensional nano-based functional materials samples 1#, 2#, and 3# on the early and later strength of cement paste were experimentally tested. The test temperatures were 30℃ and 50℃. The basic formula at 30℃ was: Grade G cement + multidimensional nano-based functional material sample + water (maintaining a liquid-to-solid ratio of 0.44). Considering practical applications, the formula containing a water loss reducing agent was selected at 50℃: Grade G cement + multidimensional nano-based functional material sample + 4% AMPS polymer water loss reducing agent + water (maintaining a liquid-to-solid ratio of 0.44). The test results are shown in Table 3.

[0061] Table 3. Influence of multidimensional nano-based functional material samples on the strength development of cement stone.

[0062]

[0063]

[0064] The experimental results above show that samples 1#, 2#, and 3# of the multi-dimensional nano-based functional materials can significantly shorten the strength-building time of cement paste and significantly improve early strength, with a 6-hour strength improvement rate of up to 421.7%. This can significantly shorten the setting time and reduce drilling costs. Furthermore, unlike traditional accelerators, cement paste with the addition of multi-dimensional nano-based functional materials still shows a significant increase in 7-day strength, with a strength improvement rate of up to 20.4%.

[0065] (4) The effects of multidimensional nano-based functional materials (samples 1, 2, and 3) on the mechanical properties of cement paste were tested using a triaxial testing machine. The cement paste was cured at 80℃ for 7 days, and core samples were then taken for triaxial testing. The sample consisted of G-grade cement + multidimensional nano-based functional material + 4% AMPS polymer-based water loss reducer + 0.2% retarder + water (maintaining a liquid-to-solid ratio of 0.44). The test results are shown in Table 4.

[0066] Table 4. Influence of multidimensional nano-based functional material samples on the mechanical properties of cement stone.

[0067]

[0068] As can be seen from the above experiments, with the increase of the amount of multidimensional nano-based functional materials 1#, 2# and 3# samples, the strength of cement stone gradually increases, the Young's modulus gradually decreases, and the Poisson's ratio gradually increases, showing a good strengthening and toughening effect, thereby significantly improving the cement stone's resistance to damage.

[0069] Experiments have shown that the multidimensional nano-based functional material of this application is a multifunctional material with multiple effects. On the one hand, it can significantly shorten the thickening time of cement slurry while improving the rheological properties of cement slurry, thus significantly accelerating the strength development of cement stone and effectively shortening the well construction cycle. On the other hand, it can significantly shorten the static gelation transition time of cement slurry and reduce the probability of fluid cross-flow. In addition, the multidimensional nano-based functional material can increase the toughness of cement stone while increasing the later strength of cement stone, thereby effectively ensuring the long-term integrity of cement stone.

[0070] The foregoing has shown and described the basic principles, main features, and advantages of this application. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this application. Various changes and modifications can be made without departing from the spirit and scope of this application. The scope of protection claimed by this application is defined by the appended claims, specification, and their equivalents.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit the scope of protection of this application. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the substance and scope of the technical solutions of this application.

Claims

1. A multi-dimensional nanobased functional material for oil well cement, characterized in that, The dispersion liquid of two-dimensional nanomaterials, the dispersion liquid of one-dimensional nanomaterials and the dispersion liquid of zero-dimensional nanomaterials; The mass ratio of the dispersion liquid of two-dimensional nanomaterials, the dispersion liquid of one-dimensional nanomaterials and the dispersion liquid of zero-dimensional nanomaterials is 5:3:2; The solid content of the dispersion liquid of two-dimensional nanomaterials is 15%-20%; The solid content of the dispersion liquid of one-dimensional nanomaterials is 5-10%; The solid content of the dispersion liquid of zero-dimensional nanomaterials is 15%-20%; The dispersion liquid of two-dimensional nanomaterials includes the dispersion liquid of nanometer calcium silicate and the dispersion liquid of nanometer sheet-shaped alumina; The mass ratio of the nanometer calcium silicate and the nanometer sheet-shaped alumina is 3:1; The size of the nanometer calcium silicate is 50-100nm; The thickness of the nanometer sheet-shaped alumina is 60-80nm; The dispersion liquid of nanometer calcium silicate is synthesized by solution precipitation method, and the raw materials and mass parts used in the synthesis are as follows: calcium nitrate 20-50 parts, calcium chloride 10-30 parts, sodium metasilicate 20-50 parts, polycarboxylic acid dispersant 10-30 parts, sulfonated aldehyde ketone polycondensate dispersant 5-10 parts; The one-dimensional nanomaterials include inorganic nanofibrous materials and organic nanofibrous materials; The inorganic nanofibrous materials are selected from one or a mixture of several of silicon nanowires, zinc oxide nanowires, silicon carbide and carbon nanotubes; The organic nanofibrous materials are selected from one or a mixture of several of nanocellulose and polyvinyl alcohol nanofibers; The mass ratio of the inorganic nanofibrous materials and the organic nanofibrous materials is 1:1; The diameters of the one-dimensional nanomaterials are all 20-60nm; The one-dimensional nanomaterials in the dispersion liquid of one-dimensional nanomaterials are surface treated by silane coupling agent and polycarboxylic acid dispersant, and the mass ratio of the silane coupling agent and the polycarboxylic acid dispersant is 2:1; The zero-dimensional nanomaterials are selected from one or a mixture of several of nanometer spherical silica and nanometer spherical alumina; The particle size of the zero-dimensional nanomaterials is 10-30nm; The zero-dimensional nanomaterials in the dispersion liquid of zero-dimensional nanomaterials are surface treated by amide copolymer containing amino and carboxyl, the relative molecular weight of the amide copolymer containing amino and carboxyl is 120000-150000, and the molecular weight distribution index is 2.0-2.

2.

2. The multi-dimensional nanometer-based functional material for oil well cement according to claim 1, wherein the relative molecular weight of the polycarboxylic acid dispersant is 60000-100000, and the molecular weight distribution index is 1.5-1.

7. ​

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