A sealing method

Abstract

The present invention relates to the technical field of hole sealing, and in particular to a hole sealing method, the hole sealing method comprising: drilling a hole at a first preset position of a coal body according to parameters of a reinforcement hole to form a reinforcement hole, sealing the reinforcement hole with a packer to form a closed first grouting cavity in the reinforcement hole, injecting a solidification-type sealing material into the first grouting cavity with a first grouting pipe to seal the reinforcement hole, drilling a hole at a second preset position of the coal body to form an extraction hole, pushing a first bag, a second bag and an extraction pipe into the extraction hole, the first bag and the second bag being arranged at intervals in an extension direction of the extraction hole, sealing between the extraction pipe and the inner wall of the extraction hole with the first bag and the second bag to form a closed second grouting cavity between the first bag and the second bag, and injecting a flexible sealing material into the second grouting cavity with the second grouting pipe to seal the extraction hole. The present invention proposes a hole sealing method, which can improve the quality of drilling and hole sealing.

Description

Technical Field

[0001] The present invention relates to the technical field of hole sealing, and in particular to a hole sealing method. Background Art

[0002] Coal mine gas extraction is an important measure to reduce the amount of gas outburst in mines and prevent gas explosions and coal and gas outburst disasters. Borehole sealing is a key link in borehole gas extraction, and the stability of the borehole sealing section is the basis for ensuring high-quality borehole extraction. In related technologies, the borehole sealing section is composed of the borehole surrounding rock coal mass, sealing filling materials and extraction pipes. Since the borehole surrounding rock coal mass has the characteristics of developed cracks, after the borehole sealing structure is formed, the borehole surrounding rock stress is re-balanced and distributed, and the sealing section changes from a pressureless state to a pressurized state. The sealing filling materials and the extraction pipe show different deformation characteristics under the same ground stress environment, which easily form leakage channels and reduce the quality of borehole sealing. Summary of the Invention

[0003] The present invention aims to solve one of the technical problems in the related art to at least a certain extent. To this end, an embodiment of the present invention provides a hole sealing method that can improve the quality of drilling hole sealing.

[0004] The sealing method of the embodiment of the present invention comprises: drilling a first preset position of the coal body to form a reinforcement hole according to the parameters of the reinforcement hole determined in advance, and conveying a packer with a first grouting pipe into the reinforcement hole; using the packer to seal the inner wall of the reinforcement hole to form a closed first grouting cavity in the reinforcement hole; using the first grouting pipe to inject a consolidation type sealing material into the first grouting cavity to seal the reinforcement hole; drilling a second preset position of the coal body to form an extraction hole, wherein a plurality of the reinforcement holes are arranged along the circumference of the extraction hole. Arranged at intervals; push the first bag, the second bag and the extraction tube into the extraction hole, and the first bag and the second bag are arranged at intervals in the extension direction of the extraction hole; use the second grouting tube to inject flexible sealing material into the first bag and the second bag, so that the first bag and the second bag are sealed between the extraction tube and the inner wall of the extraction hole, and form a closed second grouting cavity between the first bag and the second bag; use the second grouting tube to inject flexible sealing material into the second grouting cavity to seal the extraction hole.

[0005] The hole sealing method according to the embodiment of the present invention can improve the quality of drilling hole sealing.

[0006] In some embodiments, when the sealer is a third bag, the use of the first grouting pipe to inject a solidifying sealing material into the first grouting cavity to seal the reinforced hole includes: the first grouting pipe injects the solidifying sealing material into the third bag; the grouting pressure of the first grouting pipe gradually increases until it is greater than or equal to the bursting pressure of the first bursting valve and breaks through the first bursting valve, and then the grouting into the third bag is stopped; the first grouting pipe injects the solidifying sealing material into the first grouting cavity through the first bursting valve until the grouting pressure of the first grouting pipe is greater than the first preset grouting pressure, and then the grouting into the first grouting cavity is stopped.

[0007] In some embodiments, the second grouting pipe is used to inject a flexible sealing material into the second grouting cavity to seal the extraction hole, including: when the grouting pressure of the second grouting pipe gradually increases until it is greater than the bursting pressure of the second bursting valve and breaks through the second bursting valve, the second grouting pipe injects the flexible sealing material into the second grouting cavity through the second bursting valve until the grouting pressure of the second grouting pipe is greater than the second preset grouting pressure again, and then stops grouting into the second grouting cavity.

[0008] In some embodiments, the number of the reinforcement holes is at least two, and the two reinforcement holes are arranged on both sides of the extraction hole at intervals along a horizontal direction.

[0009] In some embodiments, the size of the first grouting cavity in the extension direction of the reinforcement hole is the same as the size of the first bag and the second bag in the extension direction of the extraction hole.

[0010] In some embodiments, the first preset grouting pressure is 1.5 MPa, and the second preset grouting pressure is 0.5-1 MPa.

[0011] In some embodiments, the rated holding pressure of the first bladder bag and the second bladder bag after expansion is greater than 2.5 MPa, and the grouting holding pressure in the first bladder bag and the second bladder bag is 1.5-2 MPa.

[0012] In some embodiments, the diameter of the reinforcement hole is D1, 30mm≤D1≤50mm.

[0013] In some embodiments, the flexible sealing material has a viscosity of less than 40 mPa·s within 0-30 minutes, and forms a flexible gel with a viscosity greater than 300,000 mPa·s within 120 minutes.

[0014] In some embodiments, the parameters of the reinforcement holes include the number, size, orientation and distribution of the reinforcement holes, and the parameters of the reinforcement holes are determined based on the degree of damage and ground stress of the coal rock at the location of the extraction holes. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 4 is a flow chart of a sealing method according to an embodiment of the present invention.

[0016] Figure 2 Schematic diagram of the reinforcement hole and the extraction pipe according to an embodiment of the present invention.

[0017] Reference numerals: coal body 100,

[0018] Reinforcement hole 1, first grouting cavity 101, packer 2, first grouting pipe 3, first bursting valve 301, first check valve 302, consolidated sealing material 4, extraction hole 5, second grouting cavity 501, first bag 6, second bag 7, extraction pipe 8, second grouting pipe 9, second bursting valve 901, second check valve 902, flexible sealing material 10, bracket 11, and buckle 12. DETAILED DESCRIPTION

[0019] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0020] The sealing method of an embodiment of the present invention includes: drilling a hole at a first preset position of the coal body 100 to form a reinforcement hole 1 according to the predetermined parameters of the reinforcement hole 1, and conveying a packer 2 with a first grouting pipe 3 into the reinforcement hole 1. The packer 2 is used to seal the inner wall of the reinforcement hole 1 to form a closed first grouting cavity 101 in the reinforcement hole 1. The first grouting pipe 3 is used to inject a solidifying sealing material 4 into the first grouting cavity 101 to seal the reinforcement hole 1. A hole is drilled at a second preset position of the coal body 100 to form an extraction hole 5, wherein a plurality of reinforcement holes 1 are arranged at intervals along the circumference of the extraction hole 5. The first bag 6, the second bag 7 and the extraction pipe 8 are pushed into the extraction hole 5, and the first bag 6 and the second bag 7 are arranged in the extension direction of the extraction hole 5 (such as Figure 2 The first and second bags 6 and 7 are spaced apart in the left-right direction (as shown). A second grouting pipe 9 is used to inject a flexible sealing material 10 into the first and second bags 6 and 7, thereby sealing the first and second bags 6 and 7 between the extraction pipe 8 and the inner wall of the extraction hole 5. A closed second grouting cavity 501 is formed between the first and second bags 6 and 7. The second grouting pipe 9 is used to inject a flexible sealing material 10 into the second grouting cavity 501 to seal the extraction hole 5.

[0021] Specifically, if Figure 1 and Figure 2As shown, according to the predetermined parameters of the reinforcement hole 1, an anchor drilling rig is used to drill the reinforcement hole 1 on the coal body 100, and then the packer 2 with the first grouting pipe 3 is placed at a preset depth in the reinforcement hole 1, and the orifice of the reinforcement hole 1 is blocked by the packer 2, so that a sealed first grouting cavity 101 is formed in the reinforcement hole 1, and one end of the first grouting pipe 3 passes through the packer 2 and extends into the first grouting cavity 101, so that the first grouting pipe 3 can inject the solidified sealing material 4 into the first grouting cavity 101.

[0022] The extraction hole 5 is sealed by a two-blocking and one-injection method, that is, after the extraction hole 5 is drilled, the first bag 6, the second bag 7 and the extraction tube 8 are pushed into the extraction hole 5, and the first bag 6 is located on the left side of the second bag 7. One end of the extraction tube 8 passes through the first bag 6 and the second bag 7 in sequence and extends into the extraction hole 5. One end of the second grouting tube 9 passes through the first bag 6 and is located in the second bag 7. Flexible sealing material 10 is injected into the first bag 6 and the second bag 7 through the second grouting tube 9 to make the first bag 6 and the second bag 7 expand to abut the inner wall of the extraction hole 5, and then when a closed second grouting cavity 501 is formed between the first bag 6 and the second bag 7, the injection of flexible sealing material 10 into the first bag 6 and the second bag 7 is stopped, and the second grouting tube 9 injects flexible sealing material 10 into the second grouting cavity 501 to seal the extraction hole 5.

[0023] It can be understood that if the surrounding rock structure at the location of the extraction hole 5, that is, the second preset position of the coal body 100, is relatively complete, the reinforcement hole 1 and the extraction hole 5 can be sealed at the same time. If the surrounding rock structure at the location of the extraction hole 5, that is, the second preset position of the coal body 100, is relatively broken, the reinforcement hole 1 should be sealed first, and then the extraction hole 5 should be sealed.

[0024] For example, brackets 11 and buckling pieces 12 can be provided at both the left and right ends of the first bag 6 and the left and right ends of the second bag 7 to fix and seal the gap between the second grouting pipe 9 and the bag to ensure the sealing of the bag.

[0025] The sealing method of an embodiment of the present invention is to set a reinforcement hole 1 on the circumference of the extraction hole 5, and inject a consolidated sealing material 4 into the reinforcement hole 1 to reduce the deformation of the borehole surrounding rock, and inject a flexible sealing material 10 into the extraction hole 5. By utilizing the good permeability and drilling adaptability of the flexible material, the reinforcement of the borehole surrounding rock and the adaptive combination of the flexible sealing material 10 injected into the borehole surrounding rock are achieved to form a coal body 100 structure that is rigid on the outside and soft on the inside, thereby ensuring the sealing of the extraction hole 5, improving the sealing quality and increasing the extracted gas concentration.

[0026] In some embodiments, when the sealer 2 is a third bag, the first grouting pipe 3 is used to inject the solidification type sealing material 4 into the first grouting cavity 101 to seal the reinforcement hole 1, including: the first grouting pipe 3 injects the solidification type sealing material 4 into the third bag; when the grouting pressure of the first grouting pipe 3 gradually increases until it is greater than or equal to the bursting pressure of the first bursting valve 301 and breaks through the first bursting valve 301, grouting into the third bag is stopped; the first grouting pipe 3 injects the solidification type sealing material 4 into the first grouting cavity 101 through the first bursting valve 301 until the grouting pressure of the first grouting pipe 3 is greater than the first preset grouting pressure, and grouting into the first grouting cavity 101 is stopped.

[0027] Specifically, when the sealer 2 is the third bag, the first grouting pipe 3 first injects the solidification type sealing material 4 into the third bag. When the solidification type sealing material 4 is injected into the third bag, the grouting pressure of the first grouting pipe 3 gradually increases. When the grouting pressure of the first grouting pipe 3 increases to be greater than or equal to the bursting pressure of the first bursting valve 301 and breaks through the first bursting valve 301, the first grouting pipe 3 stops grouting into the third bag and injects the solidification type sealing material 4 into the first grouting cavity 101. The end of the first grouting pipe 3 will release pressure after breaking through the first bursting valve 301, and the grouting pressure of the first grouting pipe 3 will decrease. When grouting into the first grouting cavity 101, the first grouting pipe 3 gradually increases the grouting pressure again until the grouting pressure is greater than the first preset grouting pressure, and then stops grouting into the first grouting cavity 101.

[0028] It can be understood that a first check valve 302 can also be installed on the first grouting pipe 3. The first check valve 302 is located in the third bag. The first check valve 302 prevents the slurry from flowing back. The first bursting valve 301 is installed at the end of the first grouting pipe 3, that is, the right end of the first grouting pipe 3. After the first grouting pipe 3 completes the injection of slurry into the first grouting cavity 101, the pressure is maintained for 1 minute.

[0029] In some embodiments, the second grouting pipe 9 is used to inject a flexible sealing material 10 into the second grouting cavity 501 to seal the extraction hole 5, including: when the grouting pressure of the second grouting pipe 9 gradually increases until it is greater than the bursting pressure of the second bursting valve 901 and breaks through the second bursting valve 901, the second grouting pipe 9 injects the flexible sealing material 10 into the second grouting cavity 501 through the second bursting valve 901 until the grouting pressure of the second grouting pipe 9 is greater than the second preset grouting pressure again, and then stops grouting into the second grouting cavity 501.

[0030] Specifically, the second grouting pipe 9 first injects the solidified sealing material 4 into the first bag 6 and the second bag 7. When the flexible sealing material 10 is injected into the third bag, the grouting pressure of the second grouting pipe 9 gradually increases. When the grouting pressure of the second grouting pipe 9 increases to be greater than or equal to the blasting pressure of the second blasting valve 901 and breaks through the second blasting valve 901, the second grouting pipe 9 stops grouting into the first bag 6 and the second bag 7. At this time, the first bag 6 and the second bag 7 expand and abut against the inner wall of the extraction hole 5 to close the first bag. A closed second grouting cavity 501 is formed between the bag 6 and the second bag 7. The second grouting pipe 9 injects the flexible sealing material 10 into the second grouting cavity 501 through the second bursting valve 901. The second grouting pipe 9 will release pressure after breaking through the second bursting valve 901, and the grouting pressure of the second grouting pipe 9 will decrease. When grouting into the second grouting cavity 501, the second grouting pipe 9 gradually increases the grouting pressure again until the grouting pressure is greater than the second preset grouting pressure, and then stops grouting into the second grouting cavity 501 to complete the sealing of the extraction hole 5.

[0031] It is understandable that a second check valve 902 is installed in each of the first and second bags 6 and 7 and is connected to the second grouting pipe 9 to prevent slurry backflow and ensure the sealing stability of the first and second bags 6 and 7. The second bursting valve 901 is installed in the second grouting cavity 501 and is connected to the second grouting pipe 9. The second bursting valve 901 is used to allow the second grouting pipe 9 to first inject slurry into the first and second bags 6 and 7 to ensure that a closed second grouting cavity 501 is formed between the first and second bags 6 and 7. After the second grouting pipe 9 completes the injection of slurry into the second grouting cavity 501, the pressure is maintained for 1 minute. After the flexible sealing material 10 solidifies, the grouting device is cleaned and connected to the extraction pipe 8 for extraction.

[0032] The embodiment of the present invention forms a tree-like structure in the deep coal body of the borehole surrounding rock by setting reinforcement holes around the extraction hole and injecting consolidation-type sealing materials into the reinforcement holes, thereby realizing an "anchor-bond" effect on the coal body in the plastic zone of the tunnel, suppressing the large-scale deformation of the plastic coal body of the borehole surrounding rock during the stress balance process, and utilizing the first and second bladder bags and the flexible sealing materials injected into the first and second bladder bags and the second grouting cavity to realize adaptive sealing of the extraction hole and form a flexible bonding interface of the flexible gel material in the surrounding rock, thereby ensuring self-adaptation during the deformation process of the borehole, reducing the uncoordinated deformation damage between the borehole sealing structures due to material heterogeneity, and improving the sealing effect.

[0033] In some embodiments, the number of the reinforcement holes is at least two, and the two reinforcement holes are horizontally spaced apart and arranged on both sides of the extraction hole.

[0034] Specifically, there are multiple reinforcement holes, and the extraction hole is located at the center of the multiple reinforcement holes. When the number of reinforcement holes is two, the two reinforcement holes are arranged on both sides of the extraction hole at intervals in the horizontal direction, that is, located on the left and right sides of the extraction hole, and the two reinforcement holes are arranged symmetrically with the extraction hole as the center, thereby improving the reinforcement effect of the reinforcement holes.

[0035] The embodiment of the present invention avoids damage to the plastic zone of the tunnel where the extraction hole is located under coal body stress by arranging multiple reinforcement holes at intervals around the circumference of the extraction hole, and injects consolidation-type sealing materials into the reinforcement holes to form a sealing structure to support the inward squeezing force of the borehole surrounding rock, thereby avoiding further expansion of the coal body surrounding rock cracks, overcoming the uncoordinated deformation damage caused by the load on the borehole surrounding rock during the drilling sealing process of high stress, crack development and weak structure coal body, reducing the formation of large deformation cracks in the deep part of the borehole surrounding rock, and effectively adapting to the formation of small deformation cracks in the borehole surrounding rock, which can effectively increase the high-concentration gas extraction cycle of the borehole, truly realize the dynamic sealing of the borehole, and ensure the sealing stability of the extraction hole.

[0036] For example, when the thickness of the coal body is less than or equal to two meters, the number of reinforcement holes can be set to two; when the thickness of the coal body is greater than two meters, the number of reinforcement holes can be set to four. The number of reinforcement holes is determined according to the degree of damage to the coal rock. The arrangement of the reinforcement holes around the extraction holes is actually determined according to the magnitude of horizontal stress and vertical stress. The magnitude of stress can be judged according to the borehole type structure. The present invention does not limit the specific number of reinforcement holes, which shall be subject to actual implementation.

[0037] In some embodiments, the size of the first grouting cavity in the extension direction of the reinforcement hole is the same as the size of the first bag and the second bag in the extension direction of the extraction hole.

[0038] Specifically, the length of the first grouting cavity in the left-right direction is the same as the length between the left end of the first bag and the right end of the second bag, so as to ensure that after the consolidation type sealing material is injected into the first grouting cavity in the reinforcement hole, the consolidation type sealing material forms an anchor body and a coupling body in the reinforcement hole, thereby increasing the strength, shape and integrity of the surrounding rock of the borehole and the coal body structure. By limiting the length of the first grouting cavity in the left-right direction, the reinforcement effect is ensured.

[0039] It is understandable that the reinforcement structure formed by the consolidation-type sealing material injected into the reinforcement hole must be at least as short as the stress concentration zone, and the reinforcement length must be ensured to ensure the stability of the reinforced coal body.

[0040] For example, the size of the first grouting cavity in the extension direction of the reinforcement hole can also be set to be larger than the size of the first bag and the second bag in the extension direction of the extraction hole, and the spacing distance between the first bag and the second bag is determined by the actual sealing parameters implemented.

[0041] In some embodiments, the first preset grouting pressure is 1.5 MPa, and the second preset grouting pressure is 0.5-1 MPa. In the embodiment of the present invention, by setting the first preset grouting pressure, when the first grouting pipe injects the consolidation type sealing material into the first grouting cavity, the grouting pressure of the first grouting pipe is too high and flows back into the third bag, thereby ensuring the stability of the third bag in sealing the orifice of the reinforcement hole after expansion. Moreover, when the consolidation type sealing material is injected into the first grouting cavity, the gradually increasing grouting pressure can ensure that the consolidation type sealing material forms a tree structure in the reinforcement hole, realizing the "anchor-adhesion" integration and ensuring the reinforcement effect.

[0042] The embodiment of the present invention sets a second preset grouting pressure to avoid the situation where the grouting pressure of the second grouting pipe is too high and flows back into the first bag and the second bag when the second grouting pipe injects flexible sealing material into the second grouting cavity, thereby ensuring the stability of the first bag and the second bag in sealing the extraction hole after expansion.

[0043] For example, the consolidation-type sealing material is slow-setting, micro-expansion high-strength cement or low-heat, micro-expansion urethane material, which is convenient for forming a reinforcement structure in the coal body.

[0044] In some embodiments, the rated holding pressure of the first bladder bag and the second bladder bag after expansion is greater than 2.5 MPa, and the grouting holding pressure in the first bladder bag and the second bladder bag is 1.5-2 MPa.

[0045] Specifically, by setting the rated holding pressure and grouting holding pressure of the first bag and the second bag, it is further avoided that the slurry flows back into the first bag and / or the second bag when the second grouting pipe injects the flexible sealing material into the second grouting cavity, thereby ensuring the stability of the sealing section formed by the first bag and the second bag.

[0046] In some embodiments, the diameter of the reinforcement hole is D1, 30 mm ≤ D1 ≤ 50 mm.

[0047] The embodiment of the present invention limits the diameter of the reinforcement hole to avoid excessive loss of coal rock caused by the diameter of the reinforcement hole being too large, and also avoids the diameter of the reinforcement hole being too small to achieve the reinforcement effect.

[0048] For example, the diameter of the reinforcement hole can be set to 30mm, 31.5mm, 33mm, 36mm, 38mm, 40mm, 41mm, 42.5mm, 44mm, 46mm, 49mm, or 50mm.

[0049] In some embodiments, the viscosity of the flexible sealing material is less than 40 mPa·s within 0-30 minutes, and a flexible gel having a viscosity greater than 300,000 mPa·s is formed within 120 minutes.

[0050] Specifically, by limiting the viscosity of the flexible sealing material, the fluidity of the flexible sealing material during injection and the flexibility after solidification are ensured, thereby ensuring the adaptability of the flexible sealing material.

[0051] In some embodiments, the parameters of the reinforcement holes include the number, size, orientation and distribution of the reinforcement holes. The parameters of the reinforcement holes are determined based on the degree of damage and ground stress of the coal rock at the location of the extraction holes.

[0052] Specifically, the number, orientation, size and distribution of the reinforcement holes are determined according to the degree of damage of the coal rock at the location of the extraction hole, the degree of development of the surrounding rock cracks and the direction of the surrounding rock stress, to ensure that after the consolidation-type sealing material is injected into the reinforcement hole, a reinforcement structure is formed in the coal body to form a rigid support in the coal body around the extraction hole, thereby improving the sealing quality of the extraction hole.

[0053] For example, the horizontal reinforcement holes are located on both sides of the extraction hole in the horizontal direction, and the reinforcement holes are symmetrically distributed on both sides of the extraction hole, located on both sides of the horizontal distribution, and the vertical reinforcement holes are determined according to the coal body strength and crack conditions.

[0054] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0055] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0056] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0057] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," and "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "below," "below," and "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0058] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0059] It is understood that the above embodiments are exemplary and are not to be construed as limiting the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A sealing method, characterized in that: include: According to the predetermined parameters of the reinforcement hole, drilling is performed at a first preset position of the coal body to form a reinforcement hole, and a packer with a first grouting pipe is conveyed into the reinforcement hole; Using the packer to seal the inner wall of the reinforcement hole to form a closed first grouting cavity in the reinforcement hole; Injecting a solidifying sealing material into the first grouting cavity using the first grouting pipe to seal the reinforcement hole; Drilling a second preset position of the coal body to form a drainage hole, wherein a plurality of the reinforcement holes are arranged at intervals along the circumference of the drainage hole; Pushing the first sac bag, the second sac bag and the extraction tube into the extraction hole, wherein the first sac bag and the second sac bag are spaced apart in the extending direction of the extraction hole; Injecting a flexible sealing material into the first and second bags using a second grouting pipe, so that the first and second bags are sealed between the extraction pipe and the inner wall of the extraction hole, and a closed second grouting cavity is formed between the first and second bags; The second grouting pipe is used to inject flexible sealing material into the second grouting cavity to seal the extraction hole. If the surrounding rock structure of the second preset position of the coal body at the location of the extraction hole is relatively complete, the reinforcement hole and the extraction hole can be sealed at the same time. If the surrounding rock structure of the second preset position of the coal body at the location of the extraction hole is relatively broken, the reinforcement hole is sealed first, and then the extraction hole is sealed.

2. The sealing method according to claim 1, wherein: When the packer is a third bag, the method of injecting a solidifying sealing material into the first grouting cavity by using the first grouting pipe to seal the reinforcement hole includes: The first grouting pipe injects the solidified sealing material into the third bag; When the grouting pressure of the first grouting pipe gradually increases until it is equal to or greater than the bursting pressure of the first bursting valve and breaks through the first bursting valve, grouting into the third bag is stopped; The first grouting pipe injects the solidified sealing material into the first grouting cavity through the first bursting valve until the grouting pressure of the first grouting pipe is greater than the first preset grouting pressure, and then stops grouting into the first grouting cavity.

3. The sealing method according to claim 2, wherein: The method of sealing the extraction hole by injecting a flexible sealing material into the second grouting cavity using the second grouting pipe includes: When the grouting pressure of the second grouting pipe gradually increases until it is greater than the bursting pressure of the second bursting valve and breaks through the second bursting valve, the second grouting pipe injects flexible sealing material into the second grouting cavity through the second bursting valve until the grouting pressure of the second grouting pipe is greater than the second preset grouting pressure, and then stops grouting into the second grouting cavity.

4. The sealing method according to claim 3, characterized in that: The number of the reinforcement holes is at least two, and the two reinforcement holes are arranged at both sides of the extraction hole along a horizontal interval.

5. The sealing method according to claim 3, wherein: The size of the first grouting cavity in the extension direction of the reinforcement hole is the same as the size of the first bag and the second bag in the extension direction of the extraction hole.

6. The sealing method according to claim 3, wherein: The first preset grouting pressure is 1.5 MPa, and the second preset grouting pressure is 0.5-1 MPa.

7. The sealing method according to claim 6, characterized in that: The rated holding pressure of the first bladder bag and the second bladder bag after expansion is greater than 2.5 MPa, and the grouting holding pressure in the first bladder bag and the second bladder bag is 1.5-2 MPa.

8. The sealing method according to claim 1, wherein: The diameter of the reinforcement hole is D1, 30mm≤D1≤50mm.

9. The sealing method according to claim 1, wherein: The flexible sealing material has a viscosity of less than 40 mPa·s within 0-30 minutes and forms a flexible gel with a viscosity greater than 300,000 mPa·s within 120 minutes.

10. The sealing method according to claim 1, wherein: The parameters of the reinforcement holes include the number, size, orientation and distribution of the reinforcement holes. The parameters of the reinforcement holes are determined according to the degree of damage and ground stress of the coal rock at the location of the extraction holes.

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