An inorganic bentonite gel and its low-energy consumption production process

Abstract

The present invention belongs to the technical field of bentonite, and particularly relates to a bentonite inorganic gel and a low-energy consumption production process thereof. The components thereof include raw 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. The bentonite inorganic gel provided by the present invention has excellent high-temperature resistance plugging performance and pressure-bearing performance through the combined action of bentonite, modified wollastonite powder, collagen reinforcing fiber and light calcium carbonate.

Description

Technical Field

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

[0002] Well leakage refers to the phenomenon that during the drilling process, a large amount of drilling fluid uncontrollably directly enters the formation due to the formation pressure difference. Using plugging materials is an effective measure to solve this problem. Bentonite is composed of hydrous aluminum magnesium silicate minerals with montmorillonite as the main component. Its unique mineral composition and structural characteristics endow it with strong hydrophilicity, expansibility, adhesiveness, thixotropy, etc. Bentonite is also used in plugging materials. For example, the Chinese patent application with the publication number CN113105876B discloses a drilling plugging agent with different particle size resin and calcium carbonate particle gradation, including the following components in parts by mass ratio: tap water: 100 parts, bentonite: 4.0 parts, sodium carbonate: 0.16 parts, potassium chloride: 1.0 parts, temporary plugging agent limestone powder ZD for drilling fluid: 2.0 parts, water-absorbing and swelling resin particles with different particle sizes: 1.6 - 2.5 parts, rigid mineral particle material GZD for calcium carbonate drilling fluid plugging agent with different particle particle gradations: 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 poor pressure-bearing capacity for plugging with a single water-absorbing resin, single particle size, rigid calcium carbonate particle gradation, the need for flexible material filling, and the matching of particle gradation with different-sized cracks. The Chinese patent application with the publication number CN112980406B discloses a pressure-bearing plugging composition, a pressure-bearing plugging slurry, and their preparation methods and applications. The composition includes bentonite, a deformation material, a filling material, a modified bridging material, and water. Based on 100 parts by weight of water, the content of bentonite is 1 - 7 parts by weight, the content of the deformation 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 during 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 not the main component in plugging materials.

[0004] Bentonite inorganic gel refers to an inorganic gel prepared by processes such as sodium purification, gel performance adjustment, and gel drying of bentonite. Currently, bentonite inorganic gel is mainly applied in fields such as coatings, pesticides, and daily chemicals. There are few reports on its use 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 existing in the prior art, the purpose of the present invention is to provide a bentonite inorganic gel and its low-energy consumption production process. The bentonite inorganic gel provided by the present invention has excellent high-temperature resistance plugging performance and pressure-bearing performance through the combined action of bentonite, modified wollastonite powder, collagen reinforcing fiber and light calcium carbonate.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] In one aspect of the present invention, a bentonite inorganic gel is provided, and its components include raw 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.

[0008] Preferably, the wollastonite powder includes granular wollastonite powder and acicular wollastonite powder with a mass ratio of 2-4:1.

[0009] Further preferably, the D50 of the granular wollastonite powder is ≤10 µm.

[0010] Even more preferably, the D50 of the granular wollastonite powder is 2 µm.

[0011] Further preferably, the aspect ratio of the acicular wollastonite powder is 10-15:1.

[0012] Even more preferably, the aspect ratio of the acicular wollastonite powder is 15:1.

[0013] Preferably, the catalyst is selected from at least one of phosphorous acid and p-toluenesulfonic acid.

[0014] Preferably, the preparation method of the modified wollastonite powder includes the following steps: under nitrogen protection, 1-hydroxymethylpyrazole-3-carboxylic acid and polyethylene glycol are mixed, a catalyst is added, stirring reaction is carried out, wollastonite powder is added, and stirring reaction is continued. After the reaction ends, the modified wollastonite powder is obtained.

[0015] Further preferably, the preparation method of the modified wollastonite powder includes the following steps: under nitrogen protection, 1-hydroxymethylpyrazole-3-carboxylic acid and polyethylene glycol are mixed, a catalyst is added, stirring reaction is carried out at 160-200 °C for 1-2 h, wollastonite powder is added, and stirring reaction is continued for 30-60 min. After the reaction ends, the modified wollastonite powder is obtained.

[0016] Preferably, the polyethylene glycol is selected from at least one of polyethylene glycol 200, polyethylene glycol 400 and polyethylene glycol 600.

[0017] Further preferably, the polyethylene glycol is polyethylene glycol 400.

[0018] Preferably, the mass ratio of the wollastonite powder, 1-hydroxymethylpyrazole-3-carboxylic acid, polyethylene glycol and the catalyst is 1:4 - 8:3 - 5:0.005 - 0.01.

[0019] Further preferably, the mass ratio of the wollastonite powder, 1-hydroxymethylpyrazole-3-carboxylic acid, polyethylene glycol and the catalyst is 1:6:4:0.008.

[0020] Preferably, the collagen reinforced fiber is prepared from collagen-modified cellulose.

[0021] Further preferably, the cellulose content of the collagen reinforced fiber is 99%.

[0022] Even more preferably, the average fineness of the collagen reinforced fiber is 1 - 3 mm.

[0023] Even more preferably, the average fineness of the collagen reinforced fiber is 1 mm.

[0024] Preferably, the light calcium carbonate is aragonite light calcium carbonate.

[0025] Further preferably, the aragonite light calcium carbonate is selected from rod-shaped aragonite light calcium carbonate and / or needle-shaped aragonite light calcium carbonate.

[0026] Even more preferably, the aragonite light calcium carbonate is rod-shaped aragonite light calcium carbonate.

[0027] In the second aspect of the present invention, a low-energy consumption production process for preparing the bentonite inorganic gel as described above is provided, including the following steps:

[0028] S1. Grind the original bentonite ore into powder, add water, and stir evenly to obtain the original bentonite ore slurry;

[0029] S2. Purify the original bentonite ore slurry, dehydrate the purified original bentonite ore slurry, add sodium carbonate to the dehydrated original bentonite ore slurry, and stir evenly to obtain the sodium-based modified bentonite slurry;

[0030] S3. Add the modified wollastonite powder, collagen reinforced fiber and light calcium carbonate to the sodium-based modified bentonite slurry, and stir evenly to obtain the bentonite inorganic gel slurry;

[0031] S4. Dry and crush the bentonite inorganic gel slurry to obtain the product.

[0032] Preferably, the mass concentration of the original bentonite ore slurry in step S1 is 5 - 15%.

[0033] Preferably, the purification method in step S2 is as follows: the original bentonite ore slurry is screened, the screened slurry is homogenized by a high-pressure homogenizer, the homogenized slurry is classified by a hydrocyclone, and the overflow obtained is the purified original bentonite ore slurry.

[0034] Preferably, the mesh number of the screening is 250 - 325 meshes.

[0035] Preferably, the pressure of the high-pressure homogenizer is 15 - 25 MPa.

[0036] Preferably, the specification of the hydrocyclone is φ10 mm.

[0037] Preferably, the mass concentration of the original bentonite ore slurry after dehydration in step S2 is 30 - 40%.

[0038] Preferably, the mass ratio of sodium carbonate to the original bentonite ore slurry after dehydration in step S2 is 0.2 - 0.5:10.

[0039] Preferably, the mass ratio of the sodium-based modified bentonite slurry, modified wollastonite powder, collagen reinforcing fiber and light calcium carbonate in step S3 is 100:0.5 - 2:0.5 - 2:0.5 - 1.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] 1. In the bentonite inorganic gel provided by the present invention, modified wollastonite powder, collagen reinforcing fiber and light calcium carbonate are added. Among them, the modified wollastonite powder is modified with 1-hydroxymethylpyrazole-3-carboxylic acid and polyethylene glycol to form an organic-inorganic hybrid structure. At the same time, the carboxyl groups on the surface of the modified wollastonite powder form a compatibility bond with the interlayer cations of the bentonite through hydrogen bonds, and crosslink with the amino groups of the collagen reinforcing fiber through hydrogen bonds; the azacyclic group enhances the anchoring effect on the wollastonite surface through π-π interaction; the bentonite, modified wollastonite powder, collagen reinforcing fiber and light calcium carbonate act together to form a highly stable three-dimensional network structure, making the bentonite inorganic gel have excellent high-temperature plugging performance and pressure-bearing performance.

[0042] 2. When the bentonite inorganic gel provided by the present invention includes granular wollastonite powder, acicular 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 balance of toughness and rigidity, improving the high-temperature plugging performance and pressure-bearing performance of the bentonite inorganic gel. Detailed Embodiments

[0043] In order to have a clearer understanding of the technical features, objectives and effects of the present invention, the specific implementation schemes are now described in detail.

[0044] The present invention will be further described below in conjunction with embodiments, but the present invention is not limited to the following embodiments. The implementation conditions adopted in the embodiments can be further adjusted according to different requirements of specific use, and the implementation conditions not specified are the conventional conditions in this industry. The technical features involved in each implementation manner of the present invention can be combined with each other as long as they do not conflict with each other.

[0045] In the following examples and comparative examples, unless otherwise specified, the raw materials used are all commercially available or prepared by conventional methods in this field.

[0046] Example 1 Preparation of bentonite inorganic gel:

[0047] S1. Grind the bentonite ore into powder, add water, and stir evenly to obtain a bentonite ore slurry with a mass concentration of 10%.

[0048] S2. Purify the bentonite ore slurry, dehydrate the purified bentonite ore slurry, add sodium carbonate to the dehydrated bentonite ore slurry, and stir evenly to obtain a sodium-based modified bentonite slurry.

[0049] S3. Add modified wollastonite powder, collagen reinforcing fiber, and light calcium carbonate to the sodium-based modified bentonite slurry, and stir evenly to obtain a bentonite inorganic gel slurry.

[0050] S4. Dry the bentonite inorganic gel slurry and crush it to obtain the product.

[0051] The bentonite ore was purchased from Anyang Zechuan Bentonite Co., Ltd.

[0052] The purification method in step S2 is as follows: The bentonite ore slurry is screened through a 325-mesh sieve, and the screened slurry is homogenized by a high-pressure homogenizer with a pressure of 20 MPa. The homogenized slurry is classified by a hydrocyclone (specification: φ10 mm), and the overflow obtained is the purified bentonite ore slurry.

[0053] The mass concentration of the dehydrated bentonite ore slurry in step S2 is 35%.

[0054] The mass ratio of the sodium carbonate to the dehydrated bentonite ore slurry in step S2 is 0.5:10.

[0055] The mass ratio of the sodium-based modified bentonite slurry, modified wollastonite powder, collagen reinforcing fiber, and light calcium carbonate in step S3 is 100:0.5:0.5:0.5.

[0056] The preparation method of the modified wollastonite powder described in step S3: 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 h. Then wollastonite powder is added, and the stirring reaction continues for 40 min. After the reaction ends, the modified wollastonite powder is obtained.

[0057] The mass ratio of the wollastonite powder, 1-hydroxymethylpyrazole-3-carboxylic acid, polyethylene glycol, and phosphorous acid is 1:6:4:0.008.

[0058] The wollastonite powder is composed of granular wollastonite powder and acicular wollastonite powder with a mass ratio of 3:1.

[0059] The D50 of the granular wollastonite powder is 2 µm, and it is purchased from Jiangxi Bairui Calcium Carbonate Co., Ltd., with the model GR-509.

[0060] The aspect ratio of the acicular wollastonite powder is 15:1, and it is purchased from Jiangxi Bairui Calcium Carbonate Co., Ltd., with the model GR-400.

[0061] The cellulose content of the collagen-reinforced fiber described in step S3 is 99%, the average fineness is 1 mm, and it is purchased from Changzhou Yaobang Friction Materials Factory.

[0062] The light calcium carbonate described in step S3 is rod-shaped aragonite light calcium carbonate, purchased from Guangxi Huana New Materials Co., Ltd., with the model: MP-Ro.

[0063] Example 2 Preparation of bentonite inorganic gel:

[0064] S1. Grind the bentonite ore into powder, add water, and stir evenly to obtain a bentonite ore slurry with a mass concentration of 10%.

[0065] S2. Purify the bentonite ore slurry, dehydrate the purified bentonite ore slurry, add sodium carbonate to the dehydrated bentonite ore slurry, and stir evenly to obtain a sodium-based modified bentonite slurry.

[0066] S3. Add the modified wollastonite powder, collagen-reinforced fiber, and light calcium carbonate to the sodium-based modified bentonite slurry, and stir evenly to obtain a bentonite inorganic gel slurry.

[0067] S4. Dry the bentonite inorganic gel slurry and pulverize it to obtain the product.

[0068] The bentonite ore is purchased from Anyang Zechuan Bentonite Co., Ltd.

[0069] The purification method described in step S2 is as follows: The raw bentonite ore slurry is screened through a 325-mesh sieve. The slurry passing through the sieve is homogenized by a high-pressure homogenizer with a pressure of 20 MPa. The homogenized slurry is classified by a hydrocyclone (specification: φ10 mm), and the overflow obtained is the purified raw bentonite ore slurry.

[0070] The mass concentration of the dehydrated raw bentonite ore slurry described in step S2 is 35%.

[0071] The mass ratio of sodium carbonate to the dehydrated raw bentonite ore slurry described in step S2 is 0.5:10.

[0072] The mass ratio of the sodium-based modified bentonite slurry, modified wollastonite powder, collagen reinforcing fiber, and light calcium carbonate described in step S3 is 100:0.5:0.5:0.5.

[0073] The preparation method of the modified wollastonite powder described in step S3: 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 h. Then wollastonite powder is added, and the stirring reaction continues for 40 min. After the reaction ends, the modified wollastonite powder is obtained.

[0074] The mass ratio of the wollastonite powder, 1-hydroxymethylpyrazole-3-carboxylic acid, polyethylene glycol, and phosphorous acid is 1:6:4:0.008.

[0075] The wollastonite powder is granular wollastonite powder.

[0076] The D50 of the granular wollastonite powder is 2 µm, and it is purchased from Jiangxi Bairui Calcium Carbonate Co., Ltd., model GR-509.

[0077] The cellulose content of the collagen reinforcing fiber described in step S3 is 99%, the average fineness is 1 mm, and it is purchased from Changzhou Yaobang Friction Materials Factory.

[0078] 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.

[0079] Example 3 Preparation of bentonite inorganic gel:

[0080] S1. Grind the raw bentonite ore into powder, add water, and stir evenly to obtain a raw bentonite ore slurry with a mass concentration of 10%.

[0081] S2. Purify the raw bentonite ore slurry, dehydrate the purified raw bentonite ore slurry, add sodium carbonate to the dehydrated raw bentonite ore slurry, and stir evenly to obtain a sodium-based modified bentonite slurry.

[0082] S3. Add modified wollastonite powder, collagen reinforcing fiber, and light calcium carbonate to the sodium-based modified bentonite slurry, stir evenly to obtain a bentonite inorganic gel slurry;

[0083] S4. Dry the bentonite inorganic gel slurry and then crush it to obtain the product.

[0084] The original bentonite ore was purchased from Anyang Zechuan Bentonite Co., Ltd.

[0085] The purification method described in step S2 is as follows: The original bentonite ore slurry is screened through a 325-mesh sieve. The slurry passing through the sieve is homogenized using a high-pressure homogenizer with a pressure of 20 MPa. The homogenized slurry is classified using a hydrocyclone (with a specification of φ10 mm), and the overflow obtained is the purified original bentonite ore slurry.

[0086] The mass concentration of the dehydrated original bentonite ore slurry in step S2 is 35%.

[0087] The mass ratio of sodium carbonate to the dehydrated original bentonite ore slurry in step S2 is 0.5:10.

[0088] The mass ratio of the sodium-based modified bentonite slurry, modified wollastonite powder, collagen reinforcing fiber, and light calcium carbonate in step S3 is 100:0.5:0.5:0.5.

[0089] The preparation method of the modified wollastonite powder described in step S3: 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 h. Then wollastonite powder is added, and the stirring reaction continues for 40 min. After the reaction ends, the modified wollastonite powder is obtained.

[0090] The mass ratio of the wollastonite powder, 1-hydroxymethylpyrazole-3-carboxylic acid, polyethylene glycol, and phosphorous acid is 1:6:4:0.008.

[0091] The wollastonite powder is acicular wollastonite powder.

[0092] The aspect ratio of the acicular wollastonite powder is 15:1. It is purchased from Jiangxi Bairui Calcium Carbonate Co., Ltd., model GR-400.

[0093] The cellulose content of the collagen reinforcing fiber described in step S3 is 99%, and the average fineness is 1 mm. It is purchased from Changzhou Yaobang Friction Materials Factory.

[0094] The light calcium carbonate described in step S3 is rod-shaped vaterite light calcium carbonate. It is purchased from Guangxi Huana New Materials Co., Ltd., model: MP-Ro.

[0095] Example 4 Preparation of bentonite inorganic gel:

[0096] S1. Grind the raw bentonite ore into powder, add water, and stir evenly to obtain a raw bentonite ore slurry with a mass concentration of 10%.

[0097] S2. Purify the raw bentonite ore slurry, dehydrate the purified raw bentonite ore slurry, add sodium carbonate to the dehydrated raw bentonite ore slurry, and stir evenly to obtain a sodium-based modified bentonite slurry.

[0098] S3. Add modified wollastonite powder, collagen reinforcing fiber, and light calcium carbonate to the sodium-based modified bentonite slurry, and stir evenly to obtain a bentonite inorganic gel slurry.

[0099] S4. Dry the bentonite inorganic gel slurry and then crush it to obtain the product.

[0100] The raw bentonite ore is purchased from Anyang Zechuan Bentonite Co., Ltd.

[0101] The purification method in step S2 is as follows: The raw bentonite ore slurry is screened through a 325-mesh sieve. The slurry passing through the sieve is homogenized by a high-pressure homogenizer with a pressure of 20 MPa. The homogenized slurry is classified by a hydrocyclone (specification: φ10 mm), and the overflow obtained is the purified raw bentonite ore slurry.

[0102] The mass concentration of the dehydrated raw bentonite ore slurry in step S2 is 35%.

[0103] The mass ratio of the sodium carbonate and the dehydrated raw bentonite ore slurry in step S2 is 0.5:10.

[0104] The mass ratio of the sodium-based modified bentonite slurry, modified wollastonite powder, collagen reinforcing fiber, and light calcium carbonate in step S3 is 100:0.5:0.5:0.5.

[0105] The preparation method of the modified wollastonite powder in step S3: 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 h. Then wollastonite powder is added, and the stirring reaction continues for 40 min. After the reaction is completed, the modified wollastonite powder is obtained.

[0106] The mass ratio of the wollastonite powder, 1-hydroxymethylpyrazole-3-carboxylic acid, polyethylene glycol, and phosphorous acid is 1:6:4:0.008.

[0107] The wollastonite powder consists of granular wollastonite powder and acicular wollastonite powder with a mass ratio of 3:1.

[0108] The D50 of the granular wollastonite powder is 2 µm, and it is purchased from Jiangxi Bairui Calcium Carbonate Co., Ltd., model GR-509.

[0109] The aspect ratio of the acicular wollastonite powder is 15:1, purchased from Jiangxi Bairui Calcium Carbonate Co., Ltd., model GR-400.

[0110] In step S3, the cellulose content of the collagen reinforced fiber is 99%, the average fineness is 1 mm, purchased from Changzhou Yaobang Friction Materials Factory.

[0111] In step S3, the light calcium carbonate is acicular aragonite light calcium carbonate (diameter 0.5 - 1.2 µm), purchased from Hubei Langbowan Biopharmaceutical Co., Ltd.

[0112] Preparation of bentonite inorganic gel in Comparative Example 1:

[0113] The difference from Example 1 is that the modified wollastonite powder is replaced with wollastonite powder of the same mass; the rest are the same.

[0114] Preparation of bentonite inorganic gel in Comparative Example 2:

[0115] The difference from Example 1 is that 1-hydroxymethylpyrazole-3-carboxylic acid is replaced with citric acid of the same mass; Preparation method of the modified wollastonite powder in step S3: Under nitrogen protection, citric acid and polyethylene glycol 400 are mixed, phosphorous acid is added, stirred and reacted at 160 °C for 1 h, wollastonite powder is added, and stirring and reaction continue for 40 min. After the reaction ends, the modified wollastonite powder is obtained; the rest are the same.

[0116] Preparation of bentonite inorganic gel in Comparative Example 3:

[0117] The difference from Example 1 is that the collagen reinforced fiber is replaced with carboxymethyl cellulose of the same mass, purchased from Dongguan Ruiheng Mineral Products Co., Ltd.; the rest are the same.

[0118] Preparation of bentonite inorganic gel in Comparative Example 4:

[0119] The difference from Example 1 is that the rod-shaped aragonite light calcium carbonate is replaced with spindle-shaped calcite light calcium carbonate of the same mass; the rest are the same.

[0120] Test Example 1

[0121] 1. Test objects: Bentonite inorganic gels prepared in Examples 1 - 4 and Comparative Examples 1 - 4.

[0122] 2. Test method: (1) Prepare the base slurry: Sodium bentonite, sodium chloride and water are stirred evenly according to the mass ratio of 10:1:100 to obtain the base slurry; (2) Add the bentonite inorganic gel to the base slurry and stir evenly to obtain the bentonite inorganic gel solution, and the addition amount of the bentonite inorganic gel is 1% of the mass of the base slurry; (3) Add the bentonite inorganic gel solution to the sand bed (quartz sand particle size 20 - 40 mesh) of the high-temperature and high-pressure fluid loss instrument, and test the cumulative fluid loss at 6 h under specific temperatures (120, 150 °C) and 7 MPa conditions.

[0123] 3. Test results and analysis

[0124] Table 1

[0125] Cumulative leakage volume at 120 °C (mL) Cumulative leakage volume at 150 °C (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

[0126] As can be seen from Table 1, the cumulative fluid loss of the bentonite inorganic gel in Examples 1 - 4 is less than 15 mL at 120 °C and less than or equal to 20 mL at 150 °C, indicating that the bentonite inorganic gel provided by the present invention has excellent high-temperature resistance performance, and indicating that when the vaterite light calcium carbonate in rod shape acts together with the granular wollastonite powder and the acicular wollastonite powder, the obtained bentonite inorganic gel has the best high-temperature resistance performance. Comparative Examples 1 - 4 show that the modified wollastonite powder, 1-hydroxymethylpyrazole-3-carboxylic acid, collagen reinforcing fiber and vaterite light calcium carbonate in rod shape have obvious effects on the high-temperature resistance performance of the bentonite inorganic gel.

[0127] Test Example 2

[0128] 1. Test object: The bentonite inorganic gels prepared in Examples 1 - 4 and Comparative Examples 1 - 4.

[0129] 2. Test method: (1) Prepare the base slurry: Sodium bentonite, sodium chloride and water are stirred evenly according to the mass ratio of 10:1:100 to obtain the base slurry; (2) Add the bentonite inorganic gel to the base slurry and stir evenly to obtain the bentonite inorganic gel solution, and the addition amount of the bentonite inorganic gel is 1% of the mass of the base slurry; (3) Use a steel core with a crack width of 3 mm to simulate the crack, and pour the bentonite inorganic gel solution into the core; after curing for 3 h, apply pressure at specific temperatures (120, 150 °C), and take the highest pressure when the drilling fluid shows fluid loss as the highest plugging pressure of the gel for the crack.

[0130] 3. Test results and analysis

[0131] Table 2

[0132] Highest plugging pressure at 120 °C (MPa) Highest plugging pressure at 150 °C (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

[0133] As can be seen from Table 2, the maximum plugging pressure of the bentonite inorganic gels in Examples 1-4 for cracks is greater than 4 MPa at 120 °C and greater than 3.5 MPa at 150 °C, showing good pressure-bearing capacity. Moreover, it indicates that when the fibrous aragonite light calcium carbonate acts together with the granular wollastonite powder and acicular wollastonite powder, the obtained bentonite inorganic gel has the best pressure-bearing capacity. Comparative Examples 1-4 show that the modified wollastonite powder, 1-hydroxymethylpyrazole-3-carboxylic acid, collagen reinforcing fibers and fibrous aragonite light calcium carbonate have obvious effects on the pressure-bearing capacity of the bentonite inorganic gel.

[0134] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than limiting the protection scope of the present invention. Any simple modification or equivalent replacement made by those of ordinary skill in the art to the technical solution of the present invention shall not depart 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.