Hole sealing material for coal seam gas extraction drilling as well as preparation method and application method of hole sealing material

Abstract

The invention provides a hole sealing material for coal seam gas extraction drilling as well as a preparation method and an application method of the hole sealing material, and relates to the technical field of coal seam gas (coal seam gas) exploitation. The hole sealing material for coal seam gas extraction drilling is prepared from the granulated blast furnace slag powder, the exciting agent (magnesium oxide or magnesium hydroxide) and the sulphoaluminate accelerator, and the magnesium oxide (or magnesium hydroxide) and the slag powder can be utilized to generate a gel substance under the action of water and oxygen, so that the combination among slag powder particles is firmer; therefore, the strength and the stability of the slag powder are improved; and secondly, magnesium oxide (or magnesium hydroxide) can excite the slag powder to generate the hydroxymagnesium aluminate with a layered dihydroxyl composite metal hydroxide structure, and the formation of the layered structure can hinder the permeation of water or other liquids, so that the material has certain anti-permeability performance. In this way, the hole sealing material for coal seam gas extraction drilling is high in compressive strength and excellent in anti-permeability performance.

Description

Technical Field

[0001] The invention relates to the technical field of coal bed gas (coal bed gas) mining, and in particular to a sealing material for coal bed gas extraction drilling holes and a preparation method and an application method thereof. Background Art

[0002] Coalbed methane (coalbed gas) is a clean energy source, and its development and utilization can make up for the shortage of conventional oil and gas resources to a certain extent. In the process of gas mining, the sealing quality of gas extraction boreholes largely affects whether the gas concentration meets the requirements of commercial mining. At present, cement is mostly used as a sealing material in the industry, but the effect is not good. At the same time, in order to comply with the trend of green development in the coal industry, industrial solid waste is prepared into sealing materials. While improving the sealing quality, enterprises can achieve cost reduction and efficiency improvement, and reduce the pollution of solid waste to the environment. In addition, taking the industrial solid waste slag generated by steel mills in blast furnace smelting pig iron-granulated blast furnace slag as an example, dust pollution may be generated during the processing and transportation of blast furnace slag powder, and the discharge of blast furnace slag powder wastewater will pollute local water bodies. Long-term stacking of blast furnace slag powder will pollute the soil.

[0003] Regarding the rational disposal of blast furnace slag powder, a feasible method is to mix blast furnace slag powder and alkali activator in a certain proportion to prepare coal seam gas extraction sealing grouting anti-seepage material, so as to improve the sealing quality while processing blast furnace slag powder. In the prior art, a patent disclosure document entitled "A coal seam grouting material and its application method" (application number 202310925473.1, publication date October 3, 2023) discloses a coal seam grouting material, which includes coal gangue powder, electroslag stone powder, fly ash and polycarboxylic acid water reducer. This technology solves the problem of similar technologies that grouting materials will segregate due to the sinking of powder particles during pumping, resulting in pipe blockage. The coal seam grouting material is applied to the delamination space under the key layer of the coal seam roof to achieve the purpose of reducing the settlement of the strata in the mining area. This process requires the grouting material to have high strength, but does not consider the influence of the fluidity and permeability of the grouting material on the sealing effect under different application environments.

[0004] In view of this, it is necessary to design an improved sealing material for coal seam gas extraction drilling holes and a preparation method and an application method thereof to solve the above problems. Summary of the invention

[0005] The object of the present invention is to provide a sealing material for coal seam gas extraction drilling holes and a preparation method and an application method thereof.

[0006] To achieve the above-mentioned purpose of the invention, on the one hand, the present invention provides a sealing material for coal seam gas extraction drilling, comprising the following raw materials in parts by weight:

[0007] 60-80 parts of granulated blast furnace slag powder, 10 parts of activator, 30 parts of sulphoaluminate accelerator, and 50 parts of water; the fineness of the granulated blast furnace slag powder is 90-5000 mesh, and the activity index is not less than 70%, and the activator is magnesium oxide or magnesium hydroxide.

[0008] Preferably, the sealing material for the coal seam gas extraction drilling hole further includes a water reducing agent polycarboxylic acid, and the added amount thereof is 0.1-1% of the total mass of all solid raw materials of the sealing material for the coal seam gas extraction drilling hole.

[0009] Preferably, the raw materials include the following parts by weight: 60 parts of granulated blast furnace slag powder, 10 parts of activator, 30 parts of sulphoaluminate accelerating agent, and 50 parts of water.

[0010] On the other hand, the present invention also provides a method for preparing the sealing material for coal seam gas extraction drilling, comprising the following steps:

[0011] The granulated blast furnace slag is subjected to multiple stages of grinding, drying and screening to obtain granulated blast furnace slag powder;

[0012] The granulated blast furnace slag powder, the solid waste activator and water are uniformly mixed to prepare a gel material;

[0013] After the gel material and the sulphoaluminate quick-setting agent are evenly mixed, a water reducing agent is added and mixed evenly to obtain a sealing material for coal seam gas extraction drilling holes.

[0014] Preferably, the weight proportion of the granulated blast furnace slag powder is 60-80 parts, the weight proportion of the activator is 10 parts, and the weight proportion of the sulphoaluminate accelerator is 30 parts; the water reducer is polycarboxylic acid, and its added amount is 0.1-1% of the total mass of all solid raw materials of the sealing material for the coal seam gas extraction drilling hole.

[0015] In particular, the present invention also provides an application method of the sealing material for coal seam gas extraction drilling, comprising the following steps:

[0016] S1. Mix 60-80 parts of granulated blast furnace slag powder, 10 parts of activator, 30 parts of sulphoaluminate accelerator, 50 parts of water and water reducer according to mass proportion to prepare a sealing material for coal seam gas extraction drilling;

[0017] S2, using a grouting pump to pump the sealing material of the coal seam gas extraction borehole into the sealing section of the coal seam gas extraction borehole;

[0018] S3. After grouting is completed, remove the grouting pipe, retain and seal the gas extraction pipe, and use cement to seal the orifice section, thus completing the grouting and sealing operation.

[0019] Preferably, the water reducing agent is polycarboxylic acid, and the amount of the water reducing agent added is 0.1-1% of the total mass of all solid raw materials of the sealing material for the coal seam gas extraction drilling hole.

[0020] Preferably, step S1 is performed as follows: the granulated blast furnace slag powder, solid waste activator and water are mixed evenly to obtain a gel material; after the gel material and sulphoaluminate accelerator are mixed evenly, a water reducer is added and mixed evenly to obtain the sealing material for the coal seam gas extraction drilling hole.

[0021] In particular, the present invention also provides an application method of the sealing material for coal seam gas extraction drilling, comprising the following steps:

[0022] S1. Mix 60-80 parts of granulated blast furnace slag powder, 10 parts of activator, 30 parts of sulphoaluminate accelerator and 50 parts of water in proportion by mass to obtain a sealing material for coal seam gas extraction drilling holes;

[0023] S2, using a grouting pump to pump the sealing material of the coal seam gas extraction borehole into the sealing section of the coal seam gas extraction borehole;

[0024] S3. After grouting is completed, remove the grouting pipe, retain and seal the gas extraction pipe, and use cement to seal the orifice section, thus completing the grouting and sealing operation.

[0025] The beneficial effects of the present invention are:

[0026] 1. The sealing material for coal seam gas extraction drilling provided by the present invention is prepared by using granulated blast furnace slag powder, an activator (magnesium oxide or magnesium hydroxide), and a sulphoaluminate accelerator to prepare a grouting material. Magnesium oxide (or magnesium hydroxide) and slag powder can be used to generate a gel substance under the action of water and oxygen. These gel substances have filling and bonding effects, and can fill the pores in the slag powder, so that the bonding between the slag powder particles is more firm, thereby improving the strength and stability of the slag powder; secondly, magnesium oxide (or magnesium hydroxide) can stimulate the slag powder to generate hydroxymagnesium aluminum with a layered double hydroxy composite metal hydroxide structure. The formation of the layered structure helps to hinder the penetration of water or other liquids, giving the material a certain impermeability. At the same time, the specific surface area of ​​hydroxymagnesium aluminum itself is large, which helps to increase its contact area with water or other liquids, and can also improve the material's impermeability to a certain extent. In the above manner, a sealing material for coal seam gas extraction drilling with high compressive strength and excellent impermeability is provided.

[0027] 2. The sealing material for coal seam gas extraction drilling holes provided by the present invention uses granulated blast furnace slag powder to prepare a gel material, which replaces cement in the application of grouting and sealing holes for coal seam gas extraction, thereby reducing the burden of solid waste blast furnace slag on the environment and realizing waste recycling. In addition, granulated blast furnace slag is derived from industrial solid waste slag generated when a blast furnace smelts pig iron. Using it as a raw material can not only reduce the pollution of slag to the environment, but also provide an effective method for treating solid waste and effectively reduce the cost of the grouting material preparation process.

[0028] 3. The method for preparing the sealing material for coal seam gas extraction drilling provided by the present invention has a controllable setting time of the grouting material, and the prepared grouting material has the advantages of good fluidity, high strength and low permeability.

[0029] 4. The sealing material for coal seam gas extraction drilling holes provided by the present invention can improve the sealing quality and reduce the production cost when applied to the sealing of coal seam gas extraction holes. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is the XRD pattern of the granulated blast furnace slag powder in Example 1 of the present invention;

[0031] Figure 2 This is the XRD pattern of the magnesia-based gel material synthesized in Example 1 of the present invention;

[0032] Figure 3 is a SEM image of the granulated blast furnace slag powder in Example 1 of the present invention;

[0033] Figure 4 This is a SEM image of the magnesia-based gel material synthesized in Example 1 of the present invention;

[0034] Figure 5 This is the FT-IR graph of blast furnace slag powder and gel material in Example 1 of the present invention. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the scheme of the present invention are shown in the drawings, while other details that are not closely related to the present invention are omitted.

[0037] In addition, it should be noted that the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0038] On the one hand, the present invention provides a sealing material for coal seam gas extraction drilling holes, which includes the following raw materials in parts by weight: 60-80 parts of granulated blast furnace slag powder, 10 parts of activator, 30 parts of sulphoaluminate accelerator, and 50 parts of water, wherein the fineness of the granulated blast furnace slag powder is 90-5000 mesh, the activity index is not less than 70%, and the activator is magnesium oxide (or magnesium hydroxide).

[0039] In the above technical scheme, by using granulated blast furnace slag powder and magnesium oxide (or magnesium hydroxide) as raw materials, magnesium oxide (or magnesium hydroxide) and slag powder can be used to generate gel substances under the action of water and oxygen. These gel substances have filling and bonding effects, which can fill the pores in the slag powder, make the bonding between the slag powder particles more firm, improve the gel activity of the granulated blast furnace slag powder, and make the granulated blast furnace slag powder agglomerate and bond under the action of gel, so that the grouting material can have a certain strength after solidification and low permeability; in addition, under the action of sulphoaluminate accelerator and polycarboxylic acid water reducer, the fluidity of the grouting slurry is improved, the setting time of the slurry is adjusted, and the quality of coal seam gas grouting sealing is improved.

[0040] In addition, the pH value of granulated blast furnace slag powder has a great influence on the material properties. When the pH of the slag powder is too high or too low, it is easy to cause the material performance to decline. The addition of magnesium oxide (or magnesium hydroxide) can stabilize the pH value of the slag powder and prevent the material from declining due to pH fluctuations. This is because: magnesium oxide (or magnesium hydroxide) is an alkali that can neutralize the acidic substances in the slag powder, thereby keeping the pH value of the slag powder within a relatively stable range; secondly, magnesium oxide (or magnesium hydroxide) as an activator can stimulate the slag powder to generate hydroxymagnesium aluminum oxide, which is mainly composed of compounds such as MgO and Al(OH)3, and has a layered double hydroxy composite metal hydroxide structure. The layered structure helps to hinder the penetration of water or other liquids, giving the grouting material a certain anti-seepage performance. At the same time, hydroxymagnesium aluminum oxide has a large specific surface area, which helps to increase its contact area with water or other liquids, thereby improving the material's anti-seepage performance to a certain extent. The potential of slag powder can only be realized in the presence of a liquid phase containing magnesium oxide (or magnesium hydroxide). Magnesium oxide (or magnesium hydroxide) acts as an alkaline activator and can generate an alkaline solution, which destroys the surface structure of the slag powder glass and allows water to penetrate and undergo a hydration reaction. This hydration reaction can produce gelled calcium silicate hydrate and calcium aluminate hydrate, thereby further improving the strength and stability of the slag powder.

[0041] Furthermore, in the above technical solution, by adding a sulphoaluminate accelerator, it can be used to react with water to generate calcium sulfonate, which can form a strong bridge between the slag powder particles, tightly connect the particles together, and accelerate the coagulation of the slag powder gel material; in addition to producing calcium sulfonate, the hydration products also include hydrated silica gel and aluminum gel, the formation of these products accelerates the hardening of the gel material, and at the same time, the hydration reaction of the accelerator also releases heat, the release of this heat further accelerates the coagulation process of the gel material, thereby shortening the coagulation time of the gel material, and ensuring that the material can coagulate in a short time.

[0042] In some embodiments, the sealing material for coal seam gas extraction drilling holes also includes a polycarboxylic acid water reducer, which is used as a water reducer and the added amount is 0.1-1% of the total mass of all solid raw materials of the sealing material for coal seam gas extraction drilling holes.

[0043] In the above technical solution, the polycarboxylic acid water-reducing agent can be adsorbed on the surface of the slag powder particles. The hydrophobic groups of the polycarboxylic acid will cause the particles to produce a mutual repulsive force. This repulsive force makes the slag powder particles more dispersed in the grouting material, thereby reducing the agglomeration phenomenon between the slag powder particles. The result of the dispersion effect is to improve the fluidity and plasticity of the grouting material, making the grouting material easier to construct. Secondly, the polycarboxylic acid water-reducing agent can delay the hydration reaction process of the slag powder. By adjusting the dosage of the polycarboxylic acid, the initial setting and final setting time of the grouting material can be accurately controlled to meet the needs under different construction conditions.

[0044] The method for preparing the sealing material for coal seam gas extraction drilling holes comprises the following steps:

[0045] The granulated blast furnace slag was passed through a 200 mesh screen to remove large particles of slag, and the obtained powder was placed in an oven and dried at 60° C. for 4 hours. The dried slag powder was placed in a ball mill and ground for 30 minutes at a speed of 3000 r / min to obtain granulated blast furnace slag powder;

[0046] Add solid waste stimulant to water and stir, and after stirring evenly, add granulated blast furnace slag powder and stir evenly to prepare a gel material; it should be noted that the stirring process in this step has no special requirements on temperature, stirring temperature and time, as long as the purpose of mixing evenly can be achieved; adding solid waste stimulant first can create an alkaline environment, which can better react with slag powder;

[0047] After the gel material and the sulphoaluminate quick-setting agent are evenly mixed, a water reducing agent is added and mixed evenly to obtain a sealing material for coal seam gas extraction drilling holes.

[0048] In some embodiments, the sealing material for coal seam gas extraction drilling holes also includes polycarboxylic acid, which is used as a water reducer, and the added amount is 0.1-1% of the total mass of all solid raw materials of the sealing material for coal seam gas extraction drilling holes.

[0049] On the other hand, the present invention also provides an application method of the sealing material for the coal seam gas extraction borehole, comprising the following steps:

[0050] S1. Mix 60-80 parts of granulated blast furnace slag powder, 10 parts of activator, 30 parts of sulphoaluminate accelerator, 50 parts of water and water reducer according to the mass fraction to obtain the sealing material for coal seam gas extraction drilling hole; wherein the above raw material mixing process is carried out in the following manner: add the solid waste activator to the water and stir, after stirring evenly, add the granulated blast furnace slag powder and stir evenly to obtain the gel material; after the gel material and the sulphoaluminate accelerator are mixed evenly, add the water reducer and mix evenly to obtain the sealing material for coal seam gas extraction drilling hole;

[0051] S2, using a grouting pump to pump the sealing material of the coal seam gas extraction borehole into the sealing section of the coal seam gas extraction borehole;

[0052] S3. After grouting is completed, remove the grouting pipe, retain and seal the gas extraction pipe, and use cement to seal the orifice section, thus completing the grouting and sealing operation.

[0053] In the above technical scheme, the sealing materials for the coal seam gas extraction boreholes are first configured according to the on-site needs, and then the sealing materials for the coal seam gas extraction boreholes are injected into the sealed hole section of the coal seam gas extraction hole with the help of grouting equipment such as a grouting pump. The slurry has good fluidity and the small diameter of the particles. Under the pressure of the grouting equipment, it penetrates into the cracks or pores of the coal seam in the sealed hole section. After the slurry is solidified, the strength of the consolidated body can maintain the stability of the hole wall, and the consolidated body itself has the characteristics of low permeability, thereby achieving the purpose of sealing the coal seam gas extraction hole section.

[0054] The sealing material for coal seam gas extraction drilling holes and its preparation method and application method proposed by the present invention are further described below in conjunction with specific embodiments:

[0055] Example 1

[0056] This embodiment prepares a sealing material for coal seam gas extraction drilling, which specifically includes the following steps:

[0057] The granulated blast furnace slag is passed through a 200 mesh screen, and the large particles of slag are removed. The obtained powder is placed in an oven and dried at 60° C. for 4 hours. The dried slag powder is placed in a ball mill and ground for 30 minutes at a speed of 3000 r / min to obtain granulated blast furnace slag powder with a fineness of 200-5000 mesh and an activity index greater than 70%;

[0058] Adding a solid waste activator to water and stirring, after stirring evenly, adding granulated blast furnace slag powder and stirring evenly to obtain a gel material;

[0059] After the gel material and the sulphoaluminate quick-setting agent are mixed evenly, a water reducer (specifically a polycarboxylate water reducer) is added and mixed evenly to obtain a sealing material for coal seam gas extraction drilling holes. Among them, the solid waste activator is magnesium oxide, and its mass is 10% of the total mass of all solid raw materials of the grouting material, the mass of the sulphoaluminate quick-setting agent is 10% of the total mass of all solid raw materials of the grouting material, and the amount of the water reducer added is 0.1% of the total mass of all solid raw materials of the coal seam gas extraction drilling hole sealing material.

[0060] In the above process, the XRD pattern of granulated blast furnace slag powder is as follows: Figure 1 As shown, the XRD pattern of the gel material is Figure 2 As shown in the figure, it can be seen that the blast furnace slag powder exists in a non-crystalline structure, and the main mineral components of the gel material obtained after excitation are periclase, calcite and magnesia. The SEM image of the blast furnace slag powder is shown in Figure 3 As shown, the SEM image of the gel material is Figure 4 As shown in the figure, it can be seen that the particles of blast furnace slag powder are mostly scattered in the form of fragments, while the gel material has a dense and compact structure and well-developed crystals; the FT-IR results of blast furnace slag powder and gel material are shown in Figure 5 As shown, blast furnace slag powder (red line in the figure) is at 950cm -1 There are stretching vibration peaks related to Si-O near 3444cm -1 The stretching vibration peak related to OH appears near 1643cm -1 There are absorption peaks related to the OH bending vibration in water near 1394 cm -1 The absorption peaks related to CO stretching vibration and 663 cm -1 The absorption peaks related to the bending vibration of Si-O and 450 cm -1 The absorption peaks that appear nearby are usually related to the bending vibration of Si-O-Si or Si-O-Mg.

[0061] The application method of the grouting material prepared in this embodiment comprises the following steps:

[0062] S1. Mix 60 parts of granulated blast furnace slag powder, 10 parts of activator, 30 parts of sulphoaluminate accelerator, 50 parts of water and water reducer according to the mass fraction to obtain a sealing material for coal seam gas extraction drilling holes; wherein the mixing process in this step is carried out in the following manner: add the solid waste activator to the water and stir, after stirring evenly, add the granulated blast furnace slag powder and stir evenly to obtain a gel material; after the gel material and the sulphoaluminate accelerator are mixed evenly, add the water reducer and mix evenly to obtain a sealing material for coal seam gas extraction drilling holes;

[0063] S2, using grouting equipment to pump the sealing material of the coal seam gas extraction borehole into the sealing section of the coal seam gas extraction borehole;

[0064] S3. After grouting is completed, remove the grouting pipe, retain and seal the gas extraction pipe, and use cement to seal the orifice section, thus completing the grouting and sealing operation.

[0065] Examples 2 to 3

[0066] The difference between Examples 2 to 3 and Example 1 is that the raw material ratio in the grouting material process is different from that in Example 1, and the other experimental conditions are the same as those in Example 1, which will not be repeated here. The raw material ratio of the grouting material in Examples 1 to 3 is shown in Table 2.

[0067] Table 1 Raw material ratio of grouting materials in Examples 1 to 3

[0068]

[0069] Examples 4 to 5

[0070] The only difference between Example 4 and Example 1 is that the granulated blast furnace slag powder used in Example 4 is calcined at 800°C for 2h, and the other experimental conditions are the same as those in Example 1; the only difference between Example 5 and Example 1 is that the raw materials of the grouting material also include a polycarboxylic acid water reducer, and the weight of the polycarboxylic acid water reducer is 0.1% of the weight of the solid component of the grouting material. The other experimental conditions are the same as those in Example 1 and will not be repeated here.

[0071] Table 2 Comparison of properties of grouting materials obtained under the corresponding conditions of Examples 1 to 5

[0072]

[0073] In the above embodiment, the material strength test refers to the method in "JC / T 986-2018 Cement-based Grouting Materials", and the 48h strength of the sealing material for coal seam gas extraction drilling holes is measured using a ZCYE-300C microcomputer-controlled compression and flexural testing machine. The fluidity, setting time and viscosity of the slurry are tested with reference to the method in "GB / T1304-2011 Cement Standard Consistency Water Consumption, Setting Time, and Stability Test Method" to detect the fluidity and setting time of the sealing material for coal seam gas extraction drilling holes, and the viscosity of the grouting material slurry is measured using a ZNN-D6 six-speed rotary viscometer. The permeability is measured using a TC-50 core acidification flow tester, and is expressed as the 48h permeability value of the sealing material for coal seam gas extraction drilling holes.

[0074] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A sealing material for coal seam gas extraction drilling, characterized in that: The invention comprises the following raw materials in parts by weight: 60-80 parts of granulated blast furnace slag powder, 10 parts of activator, 30 parts of sulphoaluminate accelerator, and 50 parts of water; the fineness of the granulated blast furnace slag powder is 90-5000 mesh, and the activity index is not less than 70%, and the activator is magnesium oxide or magnesium hydroxide.

2. The sealing material for coal seam gas extraction drilling according to claim 1, characterized in that: The sealing material for coal seam gas extraction drilling holes also includes a water reducing agent, polycarboxylic acid, the amount of which is 0.1-1% of the total mass of all solid raw materials of the sealing material for coal seam gas extraction drilling holes.

3. The sealing material for coal seam gas extraction drilling according to claim 2, characterized in that: The invention comprises the following raw materials in parts by weight: 60 parts of granulated blast furnace slag powder, 10 parts of activator, 30 parts of sulphoaluminate accelerating agent and 50 parts of water.

4. A method for preparing a sealing material for a coal seam gas extraction borehole according to any one of claims 1 to 3, characterized in that: The steps include: The granulated blast furnace slag is subjected to multiple stages of grinding, drying and screening to obtain granulated blast furnace slag powder; The granulated blast furnace slag powder, the solid waste activator and water are uniformly mixed to prepare a gel material; After the gel material and the sulphoaluminate quick-setting agent are evenly mixed, a water reducing agent is added and mixed evenly to obtain a sealing material for coal seam gas extraction drilling holes.

5. The preparation method according to claim 4, characterized in that: The weight proportion of the granulated blast furnace slag powder is 60-80 parts, the weight proportion of the activator is 10 parts, and the weight proportion of the sulphoaluminate quick setting agent is 30 parts; the water reducing agent is polycarboxylic acid, and its addition amount is 0.1-1% of the total weight of all solid raw materials of the sealing material for the coal seam gas extraction drilling hole.

6. A method for applying a sealing material for coal seam gas extraction drilling, characterized in that: The sealing material for coal seam gas extraction drilling is prepared by the preparation method according to any one of claims 4 to 5, and the application method comprises the following steps: S1. Mix 60-80 parts of granulated blast furnace slag powder, 10 parts of activator, 30 parts of sulphoaluminate accelerator, 50 parts of water and water reducer according to mass proportion to prepare a sealing material for coal seam gas extraction drilling; S2, using a grouting pump to pump the sealing material of the coal seam gas extraction borehole into the sealing section of the coal seam gas extraction borehole; S3. After grouting is completed, remove the grouting pipe, retain and seal the gas extraction pipe, and use cement to seal the orifice section, thus completing the grouting and sealing operation.

7. The preparation method according to claim 6, characterized in that: The water reducing agent is polycarboxylic acid, and the amount of the water reducing agent added is 0.1-1% of the total mass of all solid raw materials of the sealing material of the coal seam gas extraction drilling hole.

8. The preparation method according to claim 6, characterized in that: The step S1 is performed as follows: the granulated blast furnace slag powder, solid waste activator and water are mixed evenly to obtain a gel material; after the gel material and sulphoaluminate quick-setting agent are mixed evenly, a water reducer is added and mixed evenly to obtain the sealing material for the coal seam gas extraction drilling hole.

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