Adhesion cementing wall-fixing agent as well as preparation method and application thereof

Abstract

The invention provides an adhesion cementing wall-fixing agent and a preparation method and application thereof, and the preparation method comprises the following steps: (1) mixing polyvinyl alcohol with a first solvent to obtain a first material; (2) mixing a raw material system containing tannic acid, terephthalic acid and a pH regulator with a second solvent, and carrying out a first reaction to obtain a second material; and (3) mixing the first material with the second material, and carrying out a second reaction to obtain the adhesion cementing wall-fixing agent. The adhering and cementing wall-fixing agent provided by the invention has an excellent borehole wall stabilizing effect and can maintain the stability of the borehole wall for a long time.

Description

Technical Field

[0001] This invention relates to the field of coalbed methane reservoir development technology, specifically to an adhesive cementing and wall-stabilizing agent, its preparation method, and its application. Background Technology

[0002] Coalbed methane (CBM) is primarily composed of methane, and its reserves are abundant and widely distributed. my country's CBM exploration and development efforts have increased year by year, leading to a significant surge in drilling activity. During drilling, due to complex geological conditions and drilling techniques, wellbore instability is frequent, severely restricting drilling efficiency and safety. Coal seams, as a typical brittle rock, exhibit significantly different mechanical properties with increasing burial depth. Generally, with increasing depth, the pore pressure in the coal seam increases, while the effective stress decreases, resulting in reduced mechanical strength and increased susceptibility to fracture or collapse. The widespread presence of natural fractures, faults, and joints within coal seams also greatly affects wellbore stability. When drilling enters areas containing these weak points, localized stress concentration can easily trigger non-uniform deformation or even wellbore failure. The water content within the coal seam is also a crucial factor; the presence of moisture alters the physical properties of coal, such as its expansion coefficient and compressive strength, which to some extent exacerbates the risk of wellbore instability. For example, during drilling, if drilling fluid filtrate infiltrates the coal seam, it can cause the coal seam to absorb water and swell, further weakening its mechanical strength and leading to wellbore instability. Therefore, strengthening physical sealing and chemical bonding to prevent drilling fluid filtrate intrusion, improving coal and rock strength, and effectively inhibiting clay hydration are important technical strategies for improving wellbore stability in complex coal seams.

[0003] Chinese patent document CN112778988A discloses a cementing wall-stabilizing agent composed of six components: white oil, asphalt, rubber powder, epoxy resin, octadecyl dimethyl ammonium chloride, and water. It solidifies through chemical consolidation with the pores and cracks of the wellbore rock to form a high-strength solidified body, improving the formation's pressure-bearing capacity and strengthening the wellbore. However, the use of white oil results in poor environmental performance. Chinese patent document CN106634884A discloses a biomimetic wall-stabilizing agent made from the following raw materials in the indicated weight ratios: 85.215–85.237 parts distilled water, 9.129–9.140 parts polyphenol protein, 3.550–3.561 parts acrylamide, 2.028–2.039 parts dimethyl diallyl ammonium chloride, and 0.072–0.083 parts potassium persulfate. This wall-stabilizing agent exhibits some biodegradability, but its temperature resistance is limited. Chinese patent document CN113880501A discloses a wall-stabilizing agent for fractured strata. This agent is composed of cement, a cementitious reinforcing agent, a surface-modified microcapsule curing agent, an interface reinforcing agent, and water. After entering the formation, it solidifies under high temperature, high pressure, and alkaline conditions, improving the bonding strength and integrity of rocks in deep fractured strata and exhibiting a certain degree of self-healing ability. It shows high bonding strength with carbonate rocks, but its applicability to complex coal seams needs improvement. Chinese patent document CN116462785A provides an environmentally friendly wellbore stabilizer. This stabilizer is obtained by dissolving polyvinyl alcohol in deionized water to obtain a polyvinyl alcohol aqueous solution; fully dispersing saikosaponins in the polyvinyl alcohol aqueous solution and adjusting the pH to alkaline; reacting under stirring conditions; and then adjusting the pH to neutral and drying. However, its shale expansion rate is high, its wall-stabilizing performance needs improvement, and its applicability to coal seams is limited.

[0004] How to prepare an adhesive bonding agent with excellent wellbore stabilization effect and long-term maintenance of wellbore stability has become a research hotspot in this field. Summary of the Invention

[0005] This invention provides an adhesive bonding wall stabilizing agent, its preparation method, and its application. The adhesive bonding wall stabilizing agent is suitable for stabilizing the wellbore during coalbed methane exploration drilling, and it has excellent wellbore stabilization effect and can maintain wellbore stability for a long time.

[0006] The present invention provides a method for preparing an adhesive bonding wall-stabilizing agent, comprising the following steps: (1) mixing polyvinyl alcohol with a first solvent to obtain a first material; (2) mixing a raw material system including tannic acid, terephthalic acid and pH adjuster with a second solvent to carry out a first reaction to obtain a second material; (3) mixing the first material with the second material to carry out a second reaction to obtain the adhesive bonding wall-stabilizing agent.

[0007] Optionally, the weight-average molecular weight of the polyvinyl alcohol is 30,000 g / mol to 50,000 g / mol; and / or, the mass ratio of the polyvinyl alcohol to the volume of the first solvent is 1 g: (3 to 10) mL.

[0008] Optionally, the first solvent comprises water; and / or, the second solvent comprises water; and / or, the pH adjuster comprises sodium hydroxide.

[0009] Optionally, the mass ratio of the tannic acid to the volume of the second solvent is 1 g: (3~10) mL.

[0010] Optionally, the mass ratio of the tannic acid to the terephthalic acid is (8~12):1.

[0011] Optionally, the mass ratio of the pH adjuster to the tannic acid is (0.04~0.06):1.

[0012] Optionally, the temperature of the first reaction is 60℃~70℃; and / or, the time of the first reaction is 3.5h~4.5h.

[0013] Optionally, the mass ratio of the tannic acid to the polyvinyl alcohol is (1~1.2):1.

[0014] Optionally, the temperature of the second reaction is 60°C to 70°C; and / or the reaction time is 1 hour to 2 hours.

[0015] The present invention also provides an adhesive bonding and wall-stabilizing agent, which is prepared according to the above-described method for preparing the adhesive bonding and wall-stabilizing agent.

[0016] This invention provides an adhesive bonding wall stabilizing agent, its preparation method, and its application, which has at least the following beneficial effects: The adhesive bonding wall stabilizing agent constructs a three-dimensional cross-linked network structure based on polyvinyl alcohol, tannic acid, and terephthalic acid, achieving a synergistic effect of physical sealing and chemical bonding to solve the problem of instability in complex coal seam well walls. Hydrogen bonds are formed between the phenolic hydroxyl groups of tannic acid and the alcoholic hydroxyl groups of polyvinyl alcohol, while ester bonds are formed between tannic acid and terephthalic acid, constructing a cross-linked network structure with a rigid aromatic ring skeleton. The selective adsorption capacity of the aromatic ring skeleton with coal seam organic matter allows the adhesive bonding wall stabilizing agent to penetrate deep into microcracks and achieve stable bonding. Furthermore, the traditional white oil components are discarded in the preparation process of the adhesive bonding wall stabilizing agent; biodegradable materials (polyvinyl alcohol, tannic acid) are used, and a rigid aromatic ring structure is introduced, enabling the adhesive bonding wall stabilizing agent to balance environmental friendliness and structural stability under high-temperature environments. Detailed Implementation

[0017] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below. The specific embodiments listed below are merely descriptions of the principles and features of the present invention, and the examples are only for explaining the present invention and are not intended to limit the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] This invention provides a method for preparing an adhesive bonding and wall-stabilizing agent, comprising the following steps: (1) mixing polyvinyl alcohol with a first solvent to obtain a first material; (2) mixing a raw material system including tannic acid, terephthalic acid, and a pH adjuster with a second solvent to carry out a first reaction to obtain a second material; (3) mixing the first material with the second material to carry out a second reaction to obtain an adhesive bonding and wall-stabilizing agent.

[0019] According to research and analysis: This application embodiment constructs an adhesive bonding and wall-stabilizing agent with a three-dimensional cross-linked network structure based on polyvinyl alcohol-tannic acid-terephthalic acid. The prepared adhesive bonding and wall-stabilizing agent has a good synergistic effect of physical sealing and chemical bonding to solve the problem of instability of complex coal seam well walls. Specifically, hydrogen bonds are formed between the phenolic hydroxyl groups of tannic acid and the alcoholic hydroxyl groups of polyvinyl alcohol, and ester bonds are formed between tannic acid and terephthalic acid to construct a cross-linked network structure with a rigid aromatic ring skeleton. The selective adsorption capacity of the aromatic ring skeleton and the organic matter in the coal seam allows the adhesive bonding and wall-stabilizing agent to penetrate deep into microcracks and achieve stable bonding. In addition, the traditional white oil components are abandoned in the preparation process of the adhesive bonding and wall-stabilizing agent. Biodegradable materials (polyvinyl alcohol, tannic acid) are used and a rigid aromatic ring structure is introduced, so that the adhesive bonding and wall-stabilizing agent takes into account both environmental protection and structural stability under high temperature environment.

[0020] (1) Mix polyvinyl alcohol with a first solvent to obtain a first material.

[0021] In some specific embodiments, step (1) may include the following steps: polyvinyl alcohol and a first solvent can be stirred and mixed at 60°C to 70°C to completely dissolve the polyvinyl alcohol, and then naturally cooled to room temperature (e.g., 20°C to 25°C) to obtain the first material.

[0022] The first solvent may include water.

[0023] The weight-average molecular weight of polyvinyl alcohol can be 30,000 g / mol to 50,000 g / mol, for example, 30,000, 40,000, 50,000 g / mol or any combination thereof.

[0024] Polyvinyl alcohol with a weight-average molecular weight within the above range can improve the mechanical interlocking and physical adsorption between the adhesive wall-forming agent and the formation rocks (such as sand and clay), which helps to form a denser and more stable three-dimensional network gel structure, thereby further improving the bonding strength and erosion resistance of the adhesive wall-forming agent.

[0025] The ratio of the mass of polyvinyl alcohol to the volume of the first solvent can be 1g:(3~10)mL, for example, 1g:3mL, 1g:4mL, 1g:5mL, 1g:6mL, 1g:7mL, 1g:8mL, 1g:9mL, 1g:10mL or any combination thereof.

[0026] The ratio of the mass of polyvinyl alcohol to the volume of the first solvent within the above range is conducive to the uniform mixing of polyvinyl alcohol. At the same time, a suitable concentration of polyvinyl alcohol can further improve the adhesion and cohesive strength of the adhesive wall-fixing agent.

[0027] The stirring temperature of polyvinyl alcohol and the first solvent can be 60℃~70℃, for example, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70℃ or any combination thereof.

[0028] (2) The raw material system including tannic acid, terephthalic acid and pH adjuster is mixed with the second solvent to carry out the first reaction and obtain the second material.

[0029] In some specific embodiments, step (2) may specifically include the following steps: mixing the raw material system including tannic acid, terephthalic acid and pH adjuster with the second solvent, and carrying out the first reaction under stirring conditions of 60℃~70℃, the first reaction time can be 3.5h~4.5h, to obtain the second material.

[0030] pH adjusters may include sodium hydroxide.

[0031] The second solvent may include water.

[0032] The ratio of the mass of tannic acid to the volume of the second solvent can be 1g:(3~10)mL, for example, 1g:3mL, 1g:4mL, 1g:5mL, 1g:6mL, 1g:7mL, 1g:8mL, 1g:9mL, 1g:10mL or any combination thereof.

[0033] The ratio of tannic acid mass to the volume of the first solvent within the aforementioned range not only facilitates the uniform dispersion of tannic acid in the system but also enhances the cohesive strength and interfacial adhesion of the adhesive bonding agent by achieving a suitable tannic acid concentration. Excessive tannic acid can lead to steric hindrance and excessive self-aggregation between molecules, hindering its effective interaction with the formation surface; insufficient tannic acid results in insufficient active sites for adhesion on the material surface, similarly weakening the overall bonding performance. The mass ratio of tannic acid to terephthalic acid can be (8~12):1, for example, 8:1, 9:1, 10:1, 11:1, 12:1, or any combination thereof.

[0034] When the mass ratio of tannic acid to terephthalic acid meets the above range, it is beneficial to construct a rigid aromatic ring skeleton and better form a three-dimensional cross-linked network structure with polyvinyl alcohol, thereby further improving the structural stability of the adhesive bonding wall-fixing agent.

[0035] The mass ratio of pH adjuster to tannic acid can be (0.04~0.06):1, for example, 0.04:1, 0.05:1, 0.06:1 or any combination thereof.

[0036] When the mass ratio of pH adjuster to tannic acid meets the above range, the pH value of the second material is in the ideal range for reaction with polyvinyl alcohol, thereby promoting the formation of a structurally complete and stable three-dimensional cross-linked network structure.

[0037] The mass ratio of tannic acid to polyvinyl alcohol can be (1~1.2):1, for example, 1:1, 1.1:1, 1.2:1 or any combination thereof.

[0038] When the mass ratio of tannic acid to polyvinyl alcohol meets the above range, it is beneficial to better form a three-dimensional cross-linked network structure with tannic acid and terephthalic acid, thereby further improving the structural stability of the adhesive wall-stabilizing agent and enhancing the effect of stabilizing the well wall.

[0039] The temperature of the first reaction can be 60℃~70℃, for example, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70℃ or any combination thereof.

[0040] The temperature of the first reaction falls within the above range, which is beneficial for providing activation energy for the reaction and driving the reaction to equilibrium.

[0041] The time for the first reaction can be 3.5h to 4.5h, for example, 3.5, 4, 4.5h or any combination of two of these ranges.

[0042] The fact that the reaction time falls within the above range helps to ensure that the reaction proceeds fully and guarantees the uniformity of the product.

[0043] (3) Mix the first material with the second material to carry out the second reaction and obtain the adhesive bonding wall solidifying agent.

[0044] In some specific embodiments, step (3) may include the following steps: mixing the first material with the second material, and carrying out the second reaction at 60℃~70℃ for 1h~2h. After the reaction is completed, the material is centrifuged, dried and pulverized to obtain the adhesive bonding wall-solidifying agent.

[0045] The second reaction time can be 60℃~70℃, for example, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70℃ or any combination thereof.

[0046] The temperature and time of the second reaction both need to be appropriate; excessively high or low temperatures, or excessively short or long times, will not achieve the excellent effects of this invention. A temperature within the aforementioned range is beneficial for providing activation energy to drive the reaction to equilibrium.

[0047] The second reaction time can be 1 to 2 hours, for example, 1, 1.5, 2 hours or any combination thereof.

[0048] The timing of the second reaction, within the aforementioned range, helps ensure the reaction proceeds fully and guarantees the uniformity of the product.

[0049] Drying can include vacuum drying.

[0050] The drying time can be 60℃~70℃, for example, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70℃ or any combination thereof.

[0051] The drying time can be 10h to 15h, for example, 10, 11, 12, 13, 14, 15h or any combination thereof.

[0052] This invention also provides an adhesive bonding and wall-stabilizing agent, which is prepared according to the above-described method for preparing the adhesive bonding and wall-stabilizing agent.

[0053] The adhesive cementing wall-stabilizing agent prepared according to the above-mentioned method can effectively seal natural cracks, faults, and micropores widely present in complex coal seams through the synergistic effect of physical sealing and chemical cementation, improve coal and rock strength, significantly enhance the cementation strength of rock particles, thereby strengthening the wellbore stability of mudstone and shale during drilling, and also has a certain viscosity-enhancing effect on drilling fluid, improving mud cake quality, reducing the intrusion of drilling fluid filtrate, and effectively stabilizing the wellbore.

[0054] The adhesive bonding and wall-fixing agent prepared by this invention has a specific structure as a whole, and the various groups have complex interactions. Only through their joint action can the excellent effect of this invention be achieved.

[0055] The method of using the above-mentioned adhesive bonding wall stabilizing agent to stabilize the well wall may include: adding the adhesive bonding wall stabilizing agent to the drilling fluid or completion fluid during the coal seam drilling process, wherein the mass ratio of the adhesive bonding wall stabilizing agent to the drilling fluid or completion fluid is 1% to 5%.

[0056] Adhesive cementitious wall-stabilizing agents have a certain thickening effect on the base slurry, which can improve the quality of mud cake and reduce drilling fluid filtration loss. Adhesive cementitious wall-stabilizing agents can penetrate into the micro-fractures of the coal seam, adhere and cement between minerals, improve the cohesion between minerals, thereby increasing the stress around the well wall and preventing well wall instability.

[0057] The mass ratio of the adhesive wall-consolidating agent to the drilling fluid or completion fluid is 1% to 5%, for example, 1%, 2%, 3%, 4%, 5%, or any combination thereof.

[0058] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0059] Unless otherwise specified, the experimental methods described in the following examples are conventional methods; and the reagents and materials are commercially available unless otherwise specified.

[0060] Example 1

[0061] This embodiment provides a method for preparing an adhesive bonding and wall-stabilizing agent, the specific steps of which are as follows:

[0062] (1) Mix 10g of polyvinyl alcohol (weight average molecular weight of 40,000) with 50ml of water (distilled water, the first solvent) at 65°C for 1h to completely dissolve the polyvinyl alcohol, and then cool naturally to 20°C (room temperature) to obtain the first material;

[0063] (2) Mix the raw material system including 10g tannic acid, 1g terephthalic acid and 0.5g sodium hydroxide (pH adjuster) with 50ml water (distilled water, second solvent), stir at 65°C to carry out the first reaction for 4h, and cool naturally to room temperature to obtain the second material;

[0064] (3) Mix the first material with the second material (the second material is added to the first material), carry out the second reaction at 65°C for 1.5 hours. After the reaction is completed, a precipitate is generated. After centrifugation, it is vacuum dried at 60°C for 12 hours and then crushed to obtain the adhesive bonding wall-solidifying agent (B1).

[0065] Example 2

[0066] This embodiment is basically the same as that of embodiment 1, except that: in step (2), the mass of tannic acid used is 11g and the mass of terephthalic acid used is 1.1g. The remaining steps are the same as those of embodiment 1, and an adhesive bonding wall-fixing agent (B2) is obtained.

[0067] Example 3

[0068] This embodiment is basically the same as that of embodiment 1, except that in step (2), the mass of tannic acid used is 12g and the mass of terephthalic acid used is 1.2g. The remaining steps are the same as those of embodiment 1, and an adhesive bonding wall-fixing agent (B3) is obtained.

[0069] Example 4

[0070] This embodiment is basically the same as that of embodiment 1, except that: in step (3), the temperature of the second reaction is 60°C, and the remaining steps are the same as those of embodiment 1, to obtain the adhesive bonding wall-fixing agent (B4).

[0071] Example 5

[0072] This embodiment is basically the same as that of embodiment 1, except that: in step (3), the temperature of the second reaction is 70°C, and the remaining steps are the same as those of embodiment 1, to obtain the adhesive bonding wall-fixing agent (B5).

[0073] Example 6

[0074] This embodiment is basically the same as that of embodiment 1, except that: in step (3), the time for the second reaction is 0.5h, and the remaining steps are the same as those of embodiment 1, to obtain the adhesive bonding wall-fixing agent (B6).

[0075] Example 7

[0076] This embodiment is basically the same as that of embodiment 1, except that: in step (3), the second reaction time is 3 hours, and the remaining steps are the same as those of embodiment 1, to obtain the adhesive bonding wall-fixing agent (B7).

[0077] Example 8

[0078] This embodiment is basically the same as that of embodiment 1, except that: in step (3), the temperature of the second reaction is 55°C, and the remaining steps are the same as those of embodiment 1, to obtain the adhesive bonding wall-fixing agent (B8).

[0079] Example 9

[0080] This embodiment is basically the same as that of embodiment 1, except that: in step (3), the temperature of the second reaction is 75°C, and the remaining steps are the same as those of embodiment 1, to obtain the adhesive bonding wall-fixing agent (B9).

[0081] Example 10

[0082] This embodiment is basically the same as that of embodiment 1, except that: in step (2), the amount of tannic acid added is 7g, and the rest of the steps are the same as those of embodiment 1, to obtain the adhesive bonding wall-fixing agent (B10).

[0083] Example 11

[0084] This embodiment is basically the same as that of embodiment 1, except that: in step (2), the amount of tannic acid added is 15g, and the rest of the steps are the same as those of embodiment 1, to obtain the adhesive bonding wall-fixing agent (B11).

[0085] Example 12

[0086] This embodiment provides a method for preparing an adhesive bonding and wall-stabilizing agent, the specific steps of which are as follows:

[0087] (1) Mix 10g of polyvinyl alcohol (weight average molecular weight of 30000) with 30ml of water (distilled water, the first solvent) at 65°C for 1h to completely dissolve the polyvinyl alcohol, and then cool naturally to 20°C (room temperature) to obtain the first material;

[0088] (2) The raw material system including 8g tannic acid, 1g terephthalic acid and 0.32g sodium hydroxide (pH adjuster) is mixed with 30ml water (distilled water, second solvent), and stirred at 60℃ to carry out the first reaction for 3.5h. After naturally cooling to room temperature, the second material is obtained.

[0089] (3) Mix the first material with the second material (the second material is added to the first material), carry out the second reaction at 65°C for 1 hour. After the reaction is completed, a precipitate is generated. After centrifugation, it is vacuum dried at 60°C for 12 hours and then crushed to obtain the adhesive bonding wall-solidifying agent (B12).

[0090] Example 13

[0091] This embodiment provides a method for preparing an adhesive bonding and wall-stabilizing agent, the specific steps of which are as follows:

[0092] (1) Mix 10g of polyvinyl alcohol (weight average molecular weight of 50,000) with 100ml of water (distilled water, the first solvent) at 70°C for 2 hours to completely dissolve the polyvinyl alcohol. Then, cool naturally to 20°C (room temperature) to obtain the first material.

[0093] (2) The raw material system including 12g tannic acid, 1g terephthalic acid and 0.72g sodium hydroxide (pH adjuster) is mixed with 100ml water (distilled water, second solvent), and stirred at 70°C to carry out the first reaction for 4.5h. After naturally cooling to room temperature, the second material is obtained.

[0094] (3) Mix the first material with the second material (the second material is added to the first material), carry out the second reaction at 65°C for 2 hours. After the reaction is completed, a precipitate is generated. After centrifugation, it is vacuum dried at 60°C for 12 hours and then crushed to obtain the adhesive bonding wall-solidifying agent (B13).

[0095] Comparative Example 1

[0096] The process is basically the same as in Example 1, except that in step (2), terephthalic acid is not added, and the remaining steps are the same as in Example 1, to obtain the adhesive bonding wall-fixing agent (D1).

[0097] Comparative Example 2

[0098] The process is basically the same as in Example 1, except that in step (2), tannic acid is not added, and the remaining steps are the same as in Example 1, to obtain the adhesive bonding wall-fixing agent (D2).

[0099] Comparative Example 3

[0100] The process is basically the same as in Example 1, except that in step (1), polyvinyl alcohol is not added, and the remaining steps are the same as in Example 1, resulting in an adhesive bonding and wall-fixing agent (D3).

[0101] Test case

[0102] Test 1: Effect of Adhesive and Cementitious Wall Consolidating Agent on the Rheological Properties and Filtration Performance of the Base Pulp

[0103] 4% base slurry preparation: Add 16g bentonite and 0.56g anhydrous sodium carbonate to 400mL of water, stir thoroughly at 8000rpm for 2h at 25℃ (room temperature), and then seal and let stand for hydration for 24h.

[0104] Drilling fluid preparation: Take 400 mL of bentonite-based slurry, add 8 g of the above-prepared adhesive binder, and stir at 6000 rpm for 20 min. The test results are shown in Table 1.

[0105] Table 1. Rheological and filtration properties of drilling fluid with added adhesive binder

[0106]

[0107] Note: In the table, AV is apparent viscosity in mPa•s; PV is plastic viscosity in mPa•s; YP is dynamic shear force in Pa; FL API This is the API filtration loss, in mL.

[0108] As can be seen from Table 1, the adhesive binders and wall stabilizers B1~B13 prepared in each embodiment of the present invention have the same effect on the rheological properties and filtration performance of the base slurry, showing an increase in apparent viscosity, plastic viscosity and dynamic shear force, and a significant decrease in filtration loss, demonstrating excellent filtration loss reduction performance; while the adhesive binders and wall stabilizers D1~D5 prepared in the comparative example have weaker thickening and filtration loss reduction performance, which does not meet the application requirements.

[0109] Test 2 Uniaxial compressive strength test of core

[0110] Preparation of adhesive bonding and wall-stabilizing agent solution: Add the above-prepared adhesive bonding and wall-stabilizing agent to deionized water while stirring until the mixture is homogeneous, and prepare an adhesive bonding and wall-stabilizing agent solution with a concentration of 2wt%.

[0111] The artificial rock samples were immersed in the above-mentioned 2wt% adhesive cementitious wall-consolidating agent solution and water for 4 hours. After being removed, they were dried in a vacuum drying oven at 105℃ to constant weight, and the compressive strength was tested. The test results are shown in Table 2.

[0112] Table 2 Compressive strength test results

[0113]

[0114] As shown in Table 2, the compressive strength of coal samples soaked in water decreased significantly, but the compressive strength of coal samples soaked in solutions containing adhesive wall-binding agents B1~B13 increased significantly.

[0115] Test 3: Overlap Shear Strength Test

[0116] Preparation of adhesive bonding and wall-stabilizing agent solution: Add the above-prepared adhesive bonding and wall-stabilizing agent to deionized water while stirring until the mixture is homogeneous, and prepare an adhesive bonding and wall-stabilizing agent solution with a concentration of 2wt%.

[0117] The 2wt% adhesive wall-consolidating agent solution was evenly applied to the overlapping area of ​​the lapped specimen (rock sheet). Then, two thin sheets were gently covered and pressed at 50℃ / 3MPa for 2 hours. After that, the excess test liquid was wiped off. The lapped specimen was then placed in a 50℃ constant temperature water bath and cured for 24 hours. The specimen was then symmetrically clamped in the upper and lower clamps of the testing machine. The testing machine was started, and a longitudinal tensile shear force was applied to the single lapped surface of the specimen. The load was applied at a stable speed of 5 mm / min. The maximum load at which the specimen failed in shear in water was recorded as the lap shear strength of the adhesive wall-consolidating agent.

[0118] Table 3 Compressive strength test results

[0119]

[0120] As shown in Table 3, the adhesive bonding and wall-fixing agents prepared in Examples B1 to B13 have high measured lap shear strength and good bonding and wall-fixing effect.

[0121] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing an adhesive cementing wall stabilizer, characterized by, Includes the following steps: (1) Polyvinyl alcohol is mixed with a first solvent to obtain a first material; (2) The raw material system including tannic acid, terephthalic acid and pH adjuster is mixed with the second solvent to carry out the first reaction and obtain the second material; (3) Mix the first material with the second material to carry out a second reaction to obtain the adhesive bonding wall-fixing agent.

2. The method of preparing the adhesive cementing wall stabilizer according to claim 1, characterized in that, The weight-average molecular weight of the polyvinyl alcohol is 30,000 g / mol to 50,000 g / mol; And / or, the mass ratio of the polyvinyl alcohol to the volume of the first solvent is 1 g: (3~10) mL.

3. The method of preparing the adhesive cementing wall stabilizer according to claim 1 or 2, characterized in that, The first solvent includes water; And / or, the second solvent includes water; And / or, the pH adjuster includes sodium hydroxide.

4. The method of preparing the adhesive cementing wall stabilizer according to claim 1 or 2, characterized in that, The mass ratio of the tannic acid to the volume of the second solvent is 1 g: (3~10) mL.

5. The method of preparing the adhesive cementing wall stabilizer according to claim 1 or 2, characterized in that, The mass ratio of tannic acid to terephthalic acid is (8~12):

1.

6. The method of preparing the adhesive cementing wall stabilizer according to claim 1 or 2, characterized in that, The mass ratio of the pH adjuster to the tannic acid is (0.04~0.06):

1.

7. The method of preparing the adhesive cementing wall stabilizer according to claim 1 or 2, characterized in that, The temperature of the first reaction is 60℃~70℃; And / or, the time for the first reaction is 3.5h to 4.5h.

8. The method of preparing the adhesive cementing wall stabilizer according to claim 1 or 2, characterized in that, The mass ratio of tannic acid to polyvinyl alcohol is (1~1.2):

1.

9. The method for preparing the adhesive bonding and wall-stabilizing agent according to claim 1 or 2, characterized in that, The temperature of the second reaction is 60℃~70℃; And / or, the second reaction takes 1 to 2 hours.

10. An adhesive bonding and wall-stabilizing agent, characterized in that, The adhesive bonding and wall-stabilizing agent is prepared according to any one of claims 1-9.

Images