Methods, equipment and media for coordinated decompression and support of closely spaced coal seams

Abstract

This invention relates to the field of coal mining technology and discloses a method, equipment, and medium for coordinated pressure relief and support of closely spaced coal seams. The method includes: constructing pressure relief holes in the roof and floor of the roadway to obtain roof fracturing holes and floor fracturing holes, respectively; constructing variable-diameter pressure relief holes in the roadway using a pre-constructed variable-diameter pressure relief drill bit for the sidewall coal seam to obtain sidewall variable-diameter pressure relief holes; depressurizing the roadway based on the roof fracturing holes, floor fracturing holes, and sidewall variable-diameter pressure relief holes; and installing anchor bolts and grouting in the roof fracturing holes, floor fracturing holes, and sidewall variable-diameter pressure relief holes after pressure relief is completed to achieve full-section anchor grouting support. This invention can transform the pressure relief channel into a strong support structure, organically combining the pressure relief zone with the reinforced support zone to form an integrated and coordinated pressure relief and support system for coal mining.

Description

Technical Field

[0001] This invention relates to the field of coal mining technology, specifically to a method, equipment, and medium for coordinated decompression and support of closely spaced coal seams. Background Technology

[0002] In the mining of closely spaced coal seams, the small distance between the seams and the significant superposition effect of mining stress result in the underlying coal seam roadways experiencing intense mining pressure during excavation and mining. Traditional single-roadway support or localized decompression methods (such as roof decompression or sidewall drilling) are often insufficient to cope with this complex stress environment, frequently leading to the following problems: (1) Uncoordinated pressure relief: Only local pressure relief is applied to the roof or sidewalls, which cannot achieve coordinated pressure relief of the roof, sidewalls and floor (referred to as "roof-sidewall-floor") as a whole. Stress transfer is incomplete and the overall deformation control effect of the roadway is poor.

[0003] (2) Disconnection between support and pressure relief: The pressure relief hole has a single function and is abandoned after pressure relief is completed. It fails to be effectively combined with the subsequent support system, resulting in project waste and failure to utilize the pressure relief hole to strengthen the support system.

[0004] (3) Response lag: Decompression operations are often carried out in the mining-affected area, which is a passive response and it is difficult to weaken the high-stress area in advance before the surrounding rock of the roadway undergoes severe deformation.

[0005] (4) Backward support concept: The systematic concept of "zoning control" has not been formed. The stiffness and resistance of the support structure do not match the stress state of the surrounding rock, which leads to the support body being easily damaged in high stress areas and the support strength being excessive in low stress areas.

[0006] Therefore, how to achieve integrated and coordinated pressure relief and support in coal mine mining has become an urgent problem to be solved. Summary of the Invention

[0007] The technical problem to be solved by this invention is how to achieve integrated coordination of pressure relief and support in coal mining.

[0008] The present invention solves the above-mentioned technical problems through the following technical means: This invention provides a method for coordinated stress relief and support of closely spaced coal seam groups, characterized by comprising: Decompression holes were drilled in the roof and floor of the tunnel to obtain roof fracturing holes and floor fracturing holes. A pre-constructed variable diameter pressure relief drill bit for coal seam sidewalls was used to construct variable diameter pressure relief holes in the roadway, thereby obtaining variable diameter pressure relief holes for coal seam sidewalls. The roadway is depressurized using the top plate fracturing holes, the bottom plate fracturing holes, and the sidewall diameter-reducing depressurization holes. After the pressure relief is completed, anchor bolts are installed in the top plate fracturing holes, the bottom plate fracturing holes, and the side plate variable diameter pressure relief holes, and grouting is performed to achieve full-section anchoring support.

[0009] The present invention also provides a processing device, characterized in that it includes at least one processor and at least one memory communicatively connected to the processor, wherein: the memory stores program instructions executable by the processor, and the processor can execute the above-mentioned method for coordinated decompression and support of closely spaced coal seams by calling the program instructions.

[0010] The present invention also provides a computer-readable storage medium, characterized in that the computer-readable storage medium stores computer instructions, the computer instructions causing the computer to execute the above-described method for coordinated decompression and support of closely spaced coal seams.

[0011] The advantages of this invention are: This invention forms a complete stress relief ring around the surrounding rock through fracturing holes in the roof, floor, and variable-diameter pressure relief holes in the sidewalls. This transfers high stress around the roadway to deeper parts of the surrounding rock, achieving three-dimensional and coordinated pressure relief. Installing anchor bolts (or anchor cables) and grouting into these holes achieves full-section anchoring support. This transforms the original pressure relief channel into a powerful support structure, organically combining the pressure relief zone with the reinforced support zone, forming an integrated and coordinated system of pressure relief and support in coal mine mining. Attached Figure Description

[0012] Figure 1 This is a flowchart illustrating a method for coordinated decompression and support of closely spaced coal seams in one embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of a variable diameter pressure relief drill bit for coal seams in one embodiment of the present invention. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. 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.

[0014] Reference Figure 1 The diagram shown is a flowchart illustrating a method for coordinated stress relief and support of closely spaced coal seams according to an embodiment of the present invention. In this embodiment, the method for coordinated stress relief and support of closely spaced coal seams includes: S1. Decompression holes are constructed in the roof and floor of the tunnel to obtain roof fracturing holes and floor fracturing holes.

[0015] In this embodiment of the invention, pressure relief holes are constructed in the roof and floor of the tunnel to create roof fracturing holes and floor fracturing holes in the tunnel.

[0016] S2. Using a pre-constructed variable-diameter pressure relief drill bit for the coal seam sidewalls, a variable-diameter pressure relief hole is constructed in the roadway to obtain the variable-diameter pressure relief hole for the sidewalls. In embodiments of the present invention, such as Figure 2 As shown, the pre-constructed variable-diameter pressure relief drill bit for coal seams can drill pressure relief holes of varying diameters within the coal seam. By changing the borehole diameter, the coal seam in the flank can be disturbed and broken more effectively, creating a larger and more effective pressure relief space and fracture zone than conventional boreholes, thereby significantly releasing concentrated stress in the flank. The variable-diameter pressure relief drill bit for coal seams can adopt various structural forms, such as hydraulic drive and mechanical opening, allowing the drill bit to expand radially during drilling or after reaching its destination, forming variable-diameter pressure relief holes in the coal seam.

[0017] Specifically, the variable diameter pressure relief drill bit for the coal seam side section changes the diameter of its drill bit portion by hydraulic or mechanical means to obtain a variable diameter pressure relief hole for the side section.

[0018] S3. Depressurize the roadway according to the top plate fracturing holes, the bottom plate fracturing holes, and the side plate variable diameter depressurization holes.

[0019] In this embodiment of the invention, the step of depressurizing the roadway using the roof fracturing holes, the floor fracturing holes, and the sidewall diameter-reducing depressurization holes includes: The reverse segmented fracturing method is used to perform fracturing along the top plate fracturing holes, the bottom plate fracturing holes, and the side plate variable diameter pressure relief holes.

[0020] In detail, after the construction of the top plate fracturing holes, bottom plate fracturing holes, and side plate variable diameter pressure relief holes is completed, a fracturing system can be formed by using a hydraulic fracturing sealing device and a special hydraulic fracturing pusher. The hydraulic fracturing power is taken from the working face emulsification pump to fracture the target top plate.

[0021] While fracturing, record the pressure gauge readings and water inflow from nearby boreholes. If the pressure gauge reading reaches the predetermined pressure (26–30 MPa), maintain the pressure for 30 minutes. If water inflow from adjacent boreholes is very high, or the pressure gauge reading suddenly drops, stop fracturing at that location. Additionally, if water inflow occurs from nearby anchor bolt (cable) holes during fracturing, stop fracturing at that location.

[0022] Specifically, a hydraulic fracturing system using an emulsion pump is applied at the working face. The system pressure is 26MPa-30MPa. Fracturing is performed after drilling is completed, starting from the target layer. The section length is adjusted according to the hardness of the sandstone, and the holding time is approximately 30 minutes. Pressure gauge readings and water inflow from nearby boreholes are recorded during fracturing. If water inflow from adjacent boreholes is very high and the pressure gauge reading suddenly drops, fracturing in that borehole must be stopped. Furthermore, if water inflow occurs from nearby anchor cables during a fracturing operation, fracturing in that borehole must be stopped.

[0023] S4. After the pressure relief is completed, install anchor bolts and grout into the top plate fracturing holes, the bottom plate fracturing holes, and the side plate variable diameter pressure relief holes to achieve full-section anchoring support.

[0024] In this embodiment of the invention, after depressurizing the roadway, the roof fracturing holes, floor fracturing holes, and sidewall diameter-changing depressurization holes are cleaned and used as anchor injection holes.

[0025] Furthermore, anchor bolts (or anchor cables) are installed into the anchoring holes and grouting is performed to achieve full-section anchoring support. This transforms the original pressure relief channel into a strong support structure, organically combining the pressure relief zone with the reinforced support zone to form an integrated "pressure relief-support" system.

[0026] Preferably, during depressurization, the depressurization operation area of ​​the underlying coal seam is ensured to be outside the stress-increased zone (i.e., the mining-affected zone) caused by mining activities in the overlying working face, thus achieving spatial coordination through pre-depressurization. Simultaneously, the pre-depressurization distance (depressurization step distance) is precisely controlled to ensure that the weakening of the surrounding rock and stress release are completed before the mining impact reaches the underlying roadways, transforming passive response into proactive prevention and control, and achieving temporal coordination.

[0027] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. 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 of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for coordinated stress relief and support of closely spaced coal seam groups, characterized in that, include: Decompression holes were drilled in the roof and floor of the tunnel to obtain roof fracturing holes and floor fracturing holes. A pre-constructed variable diameter pressure relief drill bit for coal seam sidewalls was used to construct variable diameter pressure relief holes in the roadway, thereby obtaining variable diameter pressure relief holes for coal seam sidewalls. The roadway is depressurized using the top plate fracturing holes, the bottom plate fracturing holes, and the sidewall diameter-reducing depressurization holes. After the pressure relief is completed, anchor bolts are installed in the top plate fracturing holes, the bottom plate fracturing holes, and the side plate variable diameter pressure relief holes, and grouting is performed to achieve full-section anchoring support.

2. The method for coordinated stress relief and support of closely spaced coal seams as described in claim 1, characterized in that, The method of depressurizing the roadway using the roof fracturing holes, floor fracturing holes, and sidewall diameter-reducing depressurization holes includes: The reverse segmented fracturing method is used to perform fracturing along the top plate fracturing holes, the bottom plate fracturing holes, and the side plate variable diameter pressure relief holes.

3. The method for coordinated stress relief and support of closely spaced coal seams as described in claim 1, characterized in that, The variable diameter pressure relief drill bit for the coal seam side section changes the diameter of its drill bit section by hydraulic or mechanical means to obtain a variable diameter pressure relief hole for the side section.

4. A processing device, characterized in that, The method includes at least one processor and at least one memory communicatively connected to the processor, wherein the memory stores program instructions executable by the processor, and the processor can execute the method as described in any one of claims 1 to 3 by invoking the program instructions.

5. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that cause the computer to perform the method as described in any one of claims 1 to 3.

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