Bentonite inorganic gel and low-energy-consumption production process thereof

Abstract

The invention belongs to the technical field of bentonite, and particularly relates to bentonite inorganic gel and a low-energy-consumption production process thereof.The bentonite inorganic gel is prepared from bentonite raw ore, modified wollastonite powder, collagen reinforced fibers, light calcium carbonate, sodium carbonate and water; the modified wollastonite powder is prepared from the following raw materials: wollastonite powder, 1-hydroxymethyl pyrazole-3-carboxylic acid, polyethylene glycol and a catalyst. The bentonite inorganic gel provided by the invention has excellent high-temperature-resistant plugging performance and pressure-bearing performance under the combined action of the bentonite, the modified wollastonite powder, the collagen reinforced fibers and the light calcium carbonate.

Description

Technical Field

[0001] The invention belongs to the technical field of bentonite, and in particular relates to a bentonite inorganic gel and a low-energy consumption production process thereof. Background Art

[0002] Well leakage refers to the phenomenon that the drilling fluid directly enters the formation in large quantities and uncontrollably due to the formation pressure difference during the drilling process. The use of plugging materials is an effective measure to solve this problem. Bentonite is composed of hydrated aluminum-magnesium silicate minerals with montmorillonite as the main component. Its unique mineral composition and structural characteristics make it have strong hydrophilicity and expansion, adhesion and thixotropy, etc. Bentonite is also used in plugging materials. For example, the Chinese patent application with publication number CN113105876B discloses a drilling plugging agent with different particle size resins and calcium carbonate particle gradings, including the following components in mass proportions: tap water: 100 parts, bentonite: 4.0 parts, sodium carbonate: 0.16 parts, potassium chloride: 1.0 parts, drilling fluid temporary plugging agent limestone powder ZD: 2.0 parts, water-absorbing and swelling resin particles of different particle sizes: 1.6-2.5 parts, calcium carbonate drilling fluid plugging agent rigid mineral granular material GZD with different particle gradings: 3.5-4.5 parts, asbestos fiber: 3.0 parts and barite: 0-48.3 parts. The plugging agent provided by this technical solution solves the problems of pressure difference when plugging with a single water-absorbing resin, single particle size, rigid calcium carbonate particle grading and the need for flexible material filling, and particle grading matching with cracks of different sizes. The Chinese patent application with publication number CN112980406B discloses a pressure-bearing plugging composition and pressure-bearing plugging slurry and its preparation method and application. The composition includes bentonite, deformable material, filling material, modified bridging material and water, and based on 100 parts by weight of water, the content of the bentonite is 1-7 parts by weight, the content of the deformable material is 0.1-1.5 parts by weight, the content of the filling material is 8-18 parts by weight, and the content of the modified bridging material is 4-12 parts by weight; the modified bridging material includes a core and a coating layer coated on the outer surface of the core, and a paraffin layer is arranged between the core and the coating layer; the core is a water-absorbing material, and the coating layer is obtained by bonding rigid particles with a binder; the plugging filling layer formed by the pressure-bearing plugging slurry in the plugging stage can improve the pressure-bearing capacity of the formation.

[0003] It can be seen from the above technical solutions that bentonite is usually a non-main component in plugging materials.

[0004] Bentonite inorganic gel refers to an inorganic gel prepared by processes such as sodium purification of bentonite, gel performance adjustment, and gel drying. Currently, bentonite inorganic gel is mainly used in coatings, pesticides, and daily chemicals. It is rarely reported as the main component of plugging materials. Therefore, it is of great significance to provide a bentonite inorganic gel that can be used as a plugging material. Summary of the invention

[0005] Based on the defects of the prior art, the purpose of the present invention is to provide a bentonite inorganic gel and a low-energy production process thereof. The bentonite inorganic gel provided by the present invention has excellent high-temperature resistant sealing performance and pressure-bearing performance through the combined action of bentonite, modified wollastonite powder, collagen reinforced fiber and light calcium carbonate.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows: One aspect of the present invention provides a bentonite inorganic gel, the components of which include bentonite ore, modified wollastonite powder, collagen reinforcing fiber, light calcium carbonate, sodium carbonate and water; the raw materials of the modified wollastonite powder include wollastonite powder, 1-hydroxymethylpyrazole-3-carboxylic acid, polyethylene glycol and a catalyst.

[0007] Preferably, the wollastonite powder comprises granular wollastonite powder and needle-shaped wollastonite powder in a mass ratio of 2-4:1.

[0008] Further preferably, the D50 of the granular wollastonite powder is ≤10µm.

[0009] More preferably, the D50 of the granular wollastonite powder is 2 µm.

[0010] Further preferably, the aspect ratio of the needle-shaped wollastonite powder is 10-15:1.

[0011] More preferably, the aspect ratio of the needle-shaped wollastonite powder is 15:1.

[0012] Preferably, the catalyst is selected from at least one of phosphorous acid and p-toluenesulfonic acid.

[0013] Preferably, the preparation method of the modified wollastonite powder comprises the following steps: under nitrogen protection, 1-hydroxymethylpyrazole-3-carboxylic acid and polyethylene glycol are mixed, a catalyst is added, stirring the reaction is carried out, wollastonite powder is added, stirring the reaction is continued, and the modified wollastonite powder is obtained after the reaction is completed.

[0014] Further preferably, the preparation method of the modified wollastonite powder comprises the following steps: under nitrogen protection, 1-hydroxymethylpyrazole-3-carboxylic acid and polyethylene glycol are mixed, a catalyst is added, and the mixture is stirred and reacted at 160-200° C. for 1-2 hours, wollastonite powder is added, and the mixture is stirred and reacted for 30-60 minutes. After the reaction is completed, the modified wollastonite powder is obtained.

[0015] Preferably, the polyethylene glycol is selected from at least one of polyethylene glycol 200, polyethylene glycol 400 and polyethylene glycol 600.

[0016] More preferably, the polyethylene glycol is polyethylene glycol 400.

[0017] Preferably, the mass ratio of the wollastonite powder, 1-hydroxymethylpyrazole-3-carboxylic acid, polyethylene glycol and catalyst is 1:4-8:3-5:0.005-0.01.

[0018] Further preferably, the mass ratio of the wollastonite powder, 1-hydroxymethylpyrazole-3-carboxylic acid, polyethylene glycol and catalyst is 1:6:4:0.008.

[0019] Preferably, the collagen reinforced fiber is prepared from collagen-modified cellulose.

[0020] Further preferably, the cellulose content of the collagen reinforced fiber is 99%.

[0021] More preferably, the average fineness of the collagen reinforced fibers is 1-3 mm.

[0022] More preferably, the average fineness of the collagen reinforced fibers is 1 mm.

[0023] Preferably, the light calcium carbonate is aragonite light calcium carbonate.

[0024] Further preferably, the aragonite light calcium carbonate is selected from rod-shaped aragonite light calcium carbonate and / or needle-shaped aragonite light calcium carbonate.

[0025] More preferably, the aragonite light calcium carbonate is rod-shaped aragonite light calcium carbonate.

[0026] The second aspect of the present invention provides a low energy consumption production process for preparing the above-mentioned bentonite inorganic gel, comprising the following steps: S1. Grind the bentonite ore into powder, add water, and stir evenly to obtain bentonite ore slurry; S2, purifying the bentonite ore slurry, dehydrating the purified bentonite ore slurry, adding sodium carbonate to the dehydrated bentonite ore slurry, stirring evenly, and obtaining a sodium-modified bentonite slurry; S3, adding modified wollastonite powder, collagen reinforcing fiber and light calcium carbonate to the sodium-based modified bentonite slurry, stirring evenly to obtain bentonite inorganic gel slurry; S4, drying and crushing the bentonite inorganic gel slurry.

[0027] Preferably, the mass concentration of the bentonite ore slurry in step S1 is 5-15%.

[0028] Preferably, the purification method in step S2 is: the bentonite ore slurry is screened, the slurry under the screen is homogenized by a high-pressure homogenizer, the homogenized slurry is classified by a cyclone, and the overflow is the purified bentonite ore slurry.

[0029] Preferably, the mesh size of the sieving is 250-325 meshes.

[0030] Preferably, the pressure of the high-pressure homogenizer is 15-25 MPa.

[0031] Preferably, the specification of the cyclone is φ10mm.

[0032] Preferably, the mass concentration of the bentonite ore slurry after dehydration in step S2 is 30-40%.

[0033] Preferably, the mass ratio of the sodium carbonate to the dehydrated bentonite ore slurry in step S2 is 0.2-0.5:10.

[0034] Preferably, in step S3, the mass ratio of the sodium-based modified bentonite slurry, the modified wollastonite powder, the collagen reinforcing fiber and the light calcium carbonate is 100:0.5-2:0.5-2:0.5-1.

[0035] Compared with the prior art, the present invention has the following beneficial effects: 1. The bentonite inorganic gel provided by the present invention is added with modified wollastonite powder, collagen reinforced fiber and light calcium carbonate, wherein the modified wollastonite powder is modified by using 1-hydroxymethylpyrazole-3-carboxylic acid and polyethylene glycol to form an organic-inorganic hybrid structure, and at the same time, the carboxyl groups on the surface of the modified wollastonite powder form compatible bonds with the interlayer cations of the bentonite through hydrogen bonds, and are cross-linked with the amino groups of the collagen reinforced fibers through hydrogen bonds; the nitrogen heterocyclic groups enhance the anchoring effect of the surface of the wollastonite through π-π interactions; the bentonite, modified wollastonite powder, collagen reinforced fibers and light calcium carbonate work together to form a highly stable three-dimensional network structure, so that the bentonite inorganic gel has excellent high temperature resistance and sealing performance and pressure bearing performance.

[0036] 2. When the bentonite inorganic gel provided by the present invention includes granular wollastonite powder, needle-shaped wollastonite powder and rod-shaped aragonite light calcium carbonate, the multi-scale structure can not only reduce the large pore channels, but also form a three-dimensional network structure with a toughness-rigidity balance, thereby improving the high temperature resistance and pressure bearing performance of the bentonite inorganic gel. DETAILED DESCRIPTION

[0037] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, a specific implementation scheme is now described in detail.

[0038] The present invention is further described below in conjunction with the examples, but the present invention is not limited to the following examples. The implementation conditions used in the examples can be further adjusted according to the different requirements of specific use, and the implementation conditions not specified are conventional conditions in the industry. The technical features involved in each embodiment of the present invention can be combined with each other as long as they do not conflict with each other.

[0039] In the following examples and comparative examples, unless otherwise specified, all raw materials used were commercially available or prepared by conventional methods in the art.

[0040] Example 1 Preparation of bentonite inorganic gel: S1. Grind the bentonite ore into powder, add water, and stir evenly to obtain a bentonite ore slurry with a mass concentration of 10%; S2, purifying the bentonite ore slurry, dehydrating the purified bentonite ore slurry, adding sodium carbonate to the dehydrated bentonite ore slurry, stirring evenly, and obtaining a sodium-modified bentonite slurry; S3, adding modified wollastonite powder, collagen reinforcing fiber and light calcium carbonate to the sodium-based modified bentonite slurry, stirring evenly to obtain bentonite inorganic gel slurry; S4, drying and crushing the bentonite inorganic gel slurry.

[0041] The bentonite ore was purchased from Anyang Zechuan Bentonite Co., Ltd.

[0042] The purification method described in step S2 is: the bentonite ore slurry is screened through 325 mesh, the slurry under the screen is homogenized by a high-pressure homogenizer with a pressure of 20 MPa, the homogenized slurry is classified by a cyclone (specification of φ10 mm), and the overflow is the purified bentonite ore slurry.

[0043] The mass concentration of the bentonite ore slurry after dehydration in step S2 is 35%.

[0044] The mass ratio of the sodium carbonate to the dehydrated bentonite ore slurry in step S2 is 0.5:10.

[0045] The mass ratio of the sodium-based modified bentonite slurry, modified wollastonite powder, collagen reinforced fiber and light calcium carbonate in step S3 is 100:0.5:0.5:0.5.

[0046] The preparation method of the modified wollastonite powder in step S3 is as follows: under nitrogen protection, 1-hydroxymethylpyrazole-3-carboxylic acid and polyethylene glycol 400 are mixed, phosphorous acid is added, and the mixture is stirred and reacted at 180° C. for 1 hour, wollastonite powder is added, and the mixture is stirred and reacted for 40 minutes. After the reaction is completed, the modified wollastonite powder is obtained.

[0047] The mass ratio of the wollastonite powder, 1-hydroxymethylpyrazole-3-carboxylic acid, polyethylene glycol and phosphorous acid is 1:6:4:0.008.

[0048] The wollastonite powder is composed of granular wollastonite powder and needle-shaped wollastonite powder in a mass ratio of 3:1.

[0049] The granular wollastonite powder has a D50 of 2 μm and is purchased from Jiangxi Bairui Calcium Carbonate Co., Ltd., model GR-509.

[0050] The needle-shaped wollastonite powder has an aspect ratio of 15:1 and is purchased from Jiangxi Bairui Calcium Carbonate Co., Ltd., model GR-400.

[0051] The collagen-reinforced fibers in step S3 have a cellulose content of 99% and an average fineness of 1 mm, and are purchased from Changzhou Yaobang Friction Material Factory.

[0052] The light calcium carbonate described in step S3 is rod-shaped aragonite light calcium carbonate, purchased from Guangxi Huana New Materials Co., Ltd., model: MP-Ro.

[0053] Example 2 Preparation of bentonite inorganic gel: S1. Grind the bentonite ore into powder, add water, and stir evenly to obtain a bentonite ore slurry with a mass concentration of 10%; S2, purifying the bentonite ore slurry, dehydrating the purified bentonite ore slurry, adding sodium carbonate to the dehydrated bentonite ore slurry, stirring evenly, and obtaining a sodium-modified bentonite slurry; S3, adding modified wollastonite powder, collagen reinforcing fiber and light calcium carbonate to the sodium-based modified bentonite slurry, stirring evenly to obtain bentonite inorganic gel slurry; S4, drying and crushing the bentonite inorganic gel slurry.

[0054] The bentonite ore was purchased from Anyang Zechuan Bentonite Co., Ltd.

[0055] The purification method described in step S2 is: the bentonite ore slurry is screened through 325 mesh, the slurry under the screen is homogenized by a high-pressure homogenizer with a pressure of 20 MPa, the homogenized slurry is classified by a cyclone (specification of φ10 mm), and the overflow is the purified bentonite ore slurry.

[0056] The mass concentration of the bentonite ore slurry after dehydration in step S2 is 35%.

[0057] The mass ratio of the sodium carbonate to the dehydrated bentonite ore slurry in step S2 is 0.5:10.

[0058] The mass ratio of the sodium-based modified bentonite slurry, modified wollastonite powder, collagen reinforced fiber and light calcium carbonate in step S3 is 100:0.5:0.5:0.5.

[0059] The preparation method of the modified wollastonite powder in step S3 is as follows: under nitrogen protection, 1-hydroxymethylpyrazole-3-carboxylic acid and polyethylene glycol 400 are mixed, phosphorous acid is added, and the mixture is stirred and reacted at 180° C. for 1 hour, wollastonite powder is added, and the mixture is stirred and reacted for 40 minutes. After the reaction is completed, the modified wollastonite powder is obtained.

[0060] The mass ratio of the wollastonite powder, 1-hydroxymethylpyrazole-3-carboxylic acid, polyethylene glycol and phosphorous acid is 1:6:4:0.008.

[0061] The wollastonite powder is granular wollastonite powder.

[0062] The granular wollastonite powder has a D50 of 2 μm and is purchased from Jiangxi Bairui Calcium Carbonate Co., Ltd., model GR-509.

[0063] The collagen-reinforced fibers in step S3 have a cellulose content of 99% and an average fineness of 1 mm, and are purchased from Changzhou Yaobang Friction Material Factory.

[0064] The light calcium carbonate described in step S3 is rod-shaped aragonite light calcium carbonate, purchased from Guangxi Huana New Materials Co., Ltd., model: MP-Ro.

[0065] Example 3 Preparation of bentonite inorganic gel: S1. Grind the bentonite ore into powder, add water, and stir evenly to obtain a bentonite ore slurry with a mass concentration of 10%; S2, purifying the bentonite ore slurry, dehydrating the purified bentonite ore slurry, adding sodium carbonate to the dehydrated bentonite ore slurry, stirring evenly, and obtaining a sodium-modified bentonite slurry; S3, adding modified wollastonite powder, collagen reinforcing fiber and light calcium carbonate to the sodium-based modified bentonite slurry, stirring evenly to obtain bentonite inorganic gel slurry; S4, drying and crushing the bentonite inorganic gel slurry.

[0066] The bentonite ore was purchased from Anyang Zechuan Bentonite Co., Ltd.

[0067] The purification method described in step S2 is: the bentonite ore slurry is screened through 325 mesh, the slurry under the screen is homogenized by a high-pressure homogenizer with a pressure of 20 MPa, the homogenized slurry is classified by a cyclone (specification of φ10 mm), and the overflow is the purified bentonite ore slurry.

[0068] The mass concentration of the bentonite ore slurry after dehydration in step S2 is 35%.

[0069] The mass ratio of the sodium carbonate to the dehydrated bentonite ore slurry in step S2 is 0.5:10.

[0070] The mass ratio of the sodium-based modified bentonite slurry, modified wollastonite powder, collagen reinforced fiber and light calcium carbonate in step S3 is 100:0.5:0.5:0.5.

[0071] The preparation method of the modified wollastonite powder in step S3 is as follows: under nitrogen protection, 1-hydroxymethylpyrazole-3-carboxylic acid and polyethylene glycol 400 are mixed, phosphorous acid is added, and the mixture is stirred and reacted at 180° C. for 1 hour, wollastonite powder is added, and the mixture is stirred and reacted for 40 minutes. After the reaction is completed, the modified wollastonite powder is obtained.

[0072] The mass ratio of the wollastonite powder, 1-hydroxymethylpyrazole-3-carboxylic acid, polyethylene glycol and phosphorous acid is 1:6:4:0.008.

[0073] The wollastonite powder is needle-shaped wollastonite powder.

[0074] The needle-shaped wollastonite powder has an aspect ratio of 15:1 and is purchased from Jiangxi Bairui Calcium Carbonate Co., Ltd., model GR-400.

[0075] The collagen-reinforced fibers in step S3 have a cellulose content of 99% and an average fineness of 1 mm, and are purchased from Changzhou Yaobang Friction Material Factory.

[0076] The light calcium carbonate described in step S3 is rod-shaped aragonite light calcium carbonate, purchased from Guangxi Huana New Materials Co., Ltd., model: MP-Ro.

[0077] Example 4 Preparation of bentonite inorganic gel: S1. Grind the bentonite ore into powder, add water, and stir evenly to obtain a bentonite ore slurry with a mass concentration of 10%; S2, purifying the bentonite ore slurry, dehydrating the purified bentonite ore slurry, adding sodium carbonate to the dehydrated bentonite ore slurry, stirring evenly, and obtaining a sodium-modified bentonite slurry; S3, adding modified wollastonite powder, collagen reinforcing fiber and light calcium carbonate to the sodium-based modified bentonite slurry, stirring evenly to obtain bentonite inorganic gel slurry; S4, drying and crushing the bentonite inorganic gel slurry.

[0078] The bentonite ore was purchased from Anyang Zechuan Bentonite Co., Ltd.

[0079] The purification method described in step S2 is: the bentonite ore slurry is screened through 325 mesh, the slurry under the screen is homogenized by a high-pressure homogenizer with a pressure of 20 MPa, the homogenized slurry is classified by a cyclone (specification of φ10 mm), and the overflow is the purified bentonite ore slurry.

[0080] The mass concentration of the bentonite ore slurry after dehydration in step S2 is 35%.

[0081] The mass ratio of the sodium carbonate to the dehydrated bentonite ore slurry in step S2 is 0.5:10.

[0082] The mass ratio of the sodium-based modified bentonite slurry, modified wollastonite powder, collagen reinforced fiber and light calcium carbonate in step S3 is 100:0.5:0.5:0.5.

[0083] The preparation method of the modified wollastonite powder in step S3 is as follows: under nitrogen protection, 1-hydroxymethylpyrazole-3-carboxylic acid and polyethylene glycol 400 are mixed, phosphorous acid is added, and the mixture is stirred and reacted at 180° C. for 1 hour, wollastonite powder is added, and the mixture is stirred and reacted for 40 minutes. After the reaction is completed, the modified wollastonite powder is obtained.

[0084] The mass ratio of the wollastonite powder, 1-hydroxymethylpyrazole-3-carboxylic acid, polyethylene glycol and phosphorous acid is 1:6:4:0.008.

[0085] The wollastonite powder is composed of granular wollastonite powder and needle-shaped wollastonite powder in a mass ratio of 3:1.

[0086] The granular wollastonite powder has a D50 of 2 μm and is purchased from Jiangxi Bairui Calcium Carbonate Co., Ltd., model GR-509.

[0087] The needle-shaped wollastonite powder has an aspect ratio of 15:1 and is purchased from Jiangxi Bairui Calcium Carbonate Co., Ltd., model GR-400.

[0088] The collagen-reinforced fibers in step S3 have a cellulose content of 99% and an average fineness of 1 mm, and are purchased from Changzhou Yaobang Friction Material Factory.

[0089] The light calcium carbonate described in step S3 is needle-shaped aragonite light calcium carbonate (diameter 0.5-1.2 µm), which was purchased from Hubei Langbowan Biomedicine Co., Ltd.

[0090] Comparative Example 1 Preparation of bentonite inorganic gel: The difference from Example 1 is that the modified wollastonite powder is replaced with wollastonite powder of equal mass; the rest are the same.

[0091] Comparative Example 2 Preparation of bentonite inorganic gel: The difference from Example 1 is that 1-hydroxymethylpyrazole-3-carboxylic acid is replaced by citric acid of equal mass; the preparation method of the modified wollastonite powder in step S3 is as follows: under nitrogen protection, citric acid and polyethylene glycol 400 are mixed, phosphorous acid is added, stirred and reacted at 160° C. for 1 hour, wollastonite powder is added, and stirring and reacting is continued for 40 minutes. After the reaction is completed, the modified wollastonite powder is obtained; the rest are the same.

[0092] Comparative Example 3 Preparation of bentonite inorganic gel: The difference from Example 1 is that the collagen reinforcing fiber is replaced by carboxymethyl cellulose of equal mass purchased from Dongguan Ruiheng Mineral Products Co., Ltd.; the rest are the same.

[0093] Comparative Example 4 Preparation of bentonite inorganic gel: The difference from Example 1 is that the rod-shaped aragonite light calcium carbonate is replaced by the spindle calcite light calcium carbonate of the same mass; the rest are the same.

[0094] Test Example 1 1. Test object: bentonite inorganic gel prepared in Examples 1-4 and Comparative Examples 1-4.

[0095] 2. Test method: (1) Prepare base slurry: Sodium bentonite, sodium chloride and water are mixed evenly in a mass ratio of 10:1:100 to obtain base slurry; (2) Bentonite inorganic gel is added to the base slurry and mixed evenly to obtain bentonite inorganic gel solution. The amount of bentonite inorganic gel added is 1% of the mass of the base slurry; (3) Bentonite inorganic gel solution is added to the sand bed of a high-temperature and high-pressure dehydration tester (quartz sand particle size 20-40 mesh), and the cumulative leakage after 6 hours is tested under specific temperature (120, 150℃) and 7MPa conditions.

[0096] 3. Test results and analysis Table 1 Cumulative leakage at 120℃ (mL) Cumulative leakage at 150℃ (mL) Example 1 <5 <5 Example 2 12 20 Example 3 8 14 Example 4 <5 10 Comparative Example 1 47 62 Comparative Example 2 39 50 Comparative Example 3 42 56 Comparative Example 4 24 32 As can be seen from Table 1, the cumulative leakage of the bentonite inorganic gel of Examples 1-4 at 120°C is less than 15mL, and the cumulative leakage at 150°C is less than or equal to 20mL, indicating that the bentonite inorganic gel provided by the present invention has excellent high temperature resistance performance, and that the high temperature resistance of the obtained bentonite inorganic gel is the best when the rod-shaped aragonite light calcium carbonate acts together with the granular wollastonite powder and the needle-shaped wollastonite powder. Comparative Examples 1-4 show that modified wollastonite powder, 1-hydroxymethylpyrazole-3-carboxylic acid, collagen reinforced fiber and rod-shaped aragonite light calcium carbonate have a significant effect on the high temperature resistance of the bentonite inorganic gel.

[0097] Test Example 2 1. Test object: bentonite inorganic gel prepared in Examples 1-4 and Comparative Examples 1-4.

[0098] 2. Test method: (1) Prepare base slurry: Sodium bentonite, sodium chloride and water are mixed evenly in a mass ratio of 10:1:100 to obtain base slurry; (2) Bentonite inorganic gel is added to the base slurry and mixed evenly to obtain bentonite inorganic gel solution. The amount of bentonite inorganic gel added is 1% of the mass of the base slurry; (3) A steel core with a crack width of 3 mm is used to simulate a crack, and the bentonite inorganic gel solution is poured into the core; after curing for 3 hours, pressure is applied at a specific temperature (120, 150°C), and the highest pressure when the drilling fluid is lost is taken as the maximum sealing pressure of the gel on the crack.

[0099] 3. Test results and analysis Table 2 Maximum plugging pressure at 120℃ (MPa) Maximum plugging pressure at 150℃ (MPa) Example 1 6.2 6.0 Example 2 4.2 3.8 Example 3 4.9 4.6 Example 4 5.3 5.0 Comparative Example 1 2.1 1.5 Comparative Example 2 2.6 1.9 Comparative Example 3 3.1 2.6 Comparative Example 4 2.3 1.8 As can be seen from Table 2, the bentonite inorganic gel of Examples 1-4 has a maximum plugging pressure of more than 4 MPa at 120°C and a maximum plugging pressure of more than 3.5 MPa at 150°C, and has good pressure bearing capacity. It also shows that when the rod-shaped aragonite light calcium carbonate acts together with the granular wollastonite powder and the needle-shaped wollastonite powder, the bentonite inorganic gel has the best pressure bearing capacity. Comparative Examples 1-4 show that modified wollastonite powder, 1-hydroxymethylpyrazole-3-carboxylic acid, collagen reinforced fiber and rod-shaped aragonite light calcium carbonate have a significant effect on the pressure bearing capacity of the bentonite inorganic gel.

[0100] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A bentonite inorganic gel, characterized in that: Its components are composed of bentonite ore, modified wollastonite powder, collagen reinforced fiber, light calcium carbonate, sodium carbonate and water; the raw materials of the modified wollastonite powder are composed of wollastonite powder, 1-hydroxymethylpyrazole-3-carboxylic acid, polyethylene glycol and a catalyst; The light calcium carbonate is aragonite light calcium carbonate; the aragonite light calcium carbonate is selected from rod-shaped aragonite light calcium carbonate and / or needle-shaped aragonite light calcium carbonate; The catalyst is selected from at least one of phosphorous acid and p-toluenesulfonic acid.

2. The bentonite inorganic gel according to claim 1, characterized in that: The wollastonite powder comprises granular wollastonite powder and needle-shaped wollastonite powder in a mass ratio of 2-4:

1.

3. The bentonite inorganic gel according to claim 2, characterized in that: The D50 of the granular wollastonite powder is ≤10µm; the aspect ratio of the needle-shaped wollastonite powder is 10-15:

1.

4. The bentonite inorganic gel according to claim 3, characterized in that: The preparation method of the modified wollastonite powder comprises the following steps: under nitrogen protection, 1-hydroxymethylpyrazole-3-carboxylic acid and polyethylene glycol are mixed, a catalyst is added, stirring and reacting is carried out, wollastonite powder is added, stirring and reacting is continued, and the modified wollastonite powder is obtained after the reaction is completed.

5. The bentonite inorganic gel according to any one of claims 1 to 4, characterized in that: The cellulose content of the collagen reinforced fiber is 99%.

6. The bentonite inorganic gel according to claim 5, characterized in that: The average fineness of the collagen reinforced fibers is 1-3 mm.

7. The low energy consumption production process of bentonite inorganic gel according to any one of claims 1 to 6, characterized in that: The steps include: S1. Grind the bentonite ore into powder, add water, and stir evenly to obtain bentonite ore slurry; S2, purifying the bentonite ore slurry, dehydrating the purified bentonite ore slurry, adding sodium carbonate to the dehydrated bentonite ore slurry, stirring evenly, and obtaining a sodium-modified bentonite slurry; S3, adding modified wollastonite powder, collagen reinforcing fiber and light calcium carbonate to the sodium-based modified bentonite slurry, stirring evenly to obtain bentonite inorganic gel slurry; S4, drying and crushing the bentonite inorganic gel slurry.

8. The low energy consumption production process of bentonite inorganic gel according to claim 7, characterized in that: The mass ratio of the sodium-based modified bentonite slurry, modified wollastonite powder, collagen reinforced fiber and light calcium carbonate in step S3 is 100:0.5-2:0.5-2:0.5-1.