Coal and rock mass hydraulic grooving-fracturing pressure relief-gas permeability increasing treatment device and method

Abstract

The invention provides a coal and rock mass hydraulic grooving-fracturing pressure relief-gas permeability increasing treatment device and method.The coal and rock mass hydraulic grooving-fracturing pressure relief-gas permeability increasing treatment device comprises a hydraulic grooving module, a hydraulic fracturing module and a connecting piece, and the hydraulic grooving module comprises a jet device and a first conveying pipeline; the first end of the first conveying pipeline is connected with the jet device, the second end of the first conveying pipeline is connected with a cutting fluid source, and the jet device jets a target hole section of a target drill hole; the hydraulic fracturing module comprises a first packer, a constant-pressure opener and a second packer, the first packer and the second packer plug a target hole section of a target drill hole to form a fracturing cavity, and the constant-pressure opener is used for allowing fracturing fluid to flow to the fracturing cavity after the target drill hole is plugged; the connecting piece is arranged between the jet device and the first packer and used for connecting the hydraulic grooving module and the hydraulic fracturing module together. In this way, the problem that in the prior art, the working efficiency of roof pressure relief and gas drainage is low is solved.

Description

Technical Field

[0001] This invention relates to the field of mining engineering technology, and in particular to a treatment device and method for hydraulic grooving, fracturing and depressurization, and gas permeability enhancement in coal and rock masses. Background Technology

[0002] As coal resources extend into deeper, higher-stress, and higher-gas areas, the combined hazards of strong mine pressure and high gas levels in coal mines are becoming increasingly prominent, posing a key challenge to safe, efficient, and green coal mining. Complex, multi-stage coal seam deposition and tectonic evolution have generally resulted in thick, hard roofs, low-permeability coal seams, and high-gas environments, leading to severe mine pressure manifestations and low gas drainage efficiency. Currently, mine disaster management commonly employs roof pressure relief and coal seam gas drainage technologies. For roof pressure relief, boreholes are drilled at designed locations, and grooving and fracturing are performed in certain sections within the boreholes to release stress. For gas drainage, boreholes are drilled at designed locations to drain gas. In some cases, grooving and fracturing are also performed to improve gas drainage efficiency.

[0003] Whether it's roof depressurization or gas drainage, the grooving tool must first be transported to the designated position inside the borehole to complete the grooving, and then the grooving tool must be completely removed before the fracturing tool is transported into the borehole for fracturing. This requires repeated transporting and removing of tools, which is cumbersome and time-consuming, resulting in low efficiency for roof depressurization and gas drainage operations.

[0004] Therefore, how to solve the problem of low operational efficiency in roof depressurization and gas extraction in related technologies has become an important technical problem to be solved by those skilled in the art. Summary of the Invention

[0005] This invention provides a treatment device and method for hydraulic grooving, fracturing and depressurization, and gas permeability enhancement in coal and rock masses, in order to solve the problem of low efficiency in roof depressurization and gas drainage in related technologies.

[0006] This invention provides a treatment device for hydraulic grooving, fracturing, depressurization, and gas permeability enhancement in coal and rock masses, comprising: A hydraulic grooving module includes an ejector and a first delivery pipeline. A first end of the first delivery pipeline is connected to the ejector, and a second end of the first delivery pipeline is used to connect to a cutting fluid source. The ejector is used to jet fluid into a target hole section of a target borehole to cut a groove. The hydraulic fracturing module includes a first packer, a constant pressure opener, and a second packer connected in sequence. The first packer and the second packer are used to seal the target borehole section to form a fracturing cavity. The constant pressure opener is used to allow fracturing fluid to be delivered to the fracturing cavity after the first packer and the second packer have completed the sealing of the target borehole. A connector is located between the jet injector and the first packer. The connector is used to connect the hydraulic grooving module and the hydraulic fracturing module together.

[0007] According to the present invention, a treatment device for hydraulic grooving, fracturing and depressurization, and gas permeability enhancement in coal and rock mass is provided. The first packer has a first support tube body, the first end of the first support tube body is closed, the second end of the first support tube body is open, and the first end of the first support tube body is threadedly connected to a connector. The constant pressure opener has a second support tube body with open ends, and the first end of the second support tube body is threadedly connected to the second end of the first support tube body. The second packer has a third support tube, with both ends of the third support tube open, and the first end of the third support tube is threadedly connected to the second end of the second support tube. The first conveying pipeline passes through the interior of the third support pipe, the second support pipe and the first support pipe. The first conveying pipeline passes through the first end of the first support pipe and is sealed. There is a gap between the outer wall of the first conveying pipeline and the inner wall of the first support pipe, the second support pipe and the third support pipe.

[0008] The coal and rock mass hydraulic cutting-fracturing-pressure relief-gas permeability enhancement treatment device provided by the present invention further includes: The second delivery pipeline is located on the side of the second packer away from the ejector. The first end of the second delivery pipeline is connected to the second end of the third support pipe. The second end of the second delivery pipeline is used to connect to the fracturing fluid source. The first delivery pipeline passes through the interior of the second delivery pipeline. There is a gap between the outer wall of the first delivery pipeline and the inner wall of the first delivery pipeline.

[0009] According to the present invention, a hydraulic grooving-fracturing-pressure relief-gas permeability enhancement treatment device for coal and rock masses includes a second conveying pipeline comprising: At least two conveying pipe sections, any two conveying pipe sections can be connected by threads, and any one conveying pipe section can be connected by threads to the second end of the third support pipe section.

[0010] According to the present invention, a hydraulic cutting-fracturing-pressure relief-gas permeability enhancement treatment device for coal and rock masses is provided, wherein the first conveying pipeline is a flexible hose, the second conveying pipeline is a rigid pipe, and the device further includes: A release mechanism is disposed between the first end of the second conveying pipeline and the second end of the third support pipe. One end of the release mechanism is threadedly connected to the second end of the third support pipe, and the other end of the release mechanism is threadedly connected to the first end of the second conveying pipeline.

[0011] According to the present invention, a treatment device for hydraulic grooving, fracturing, depressurization, and gas permeability enhancement in coal and rock mass is provided, wherein the first packer and the second packer are hydraulic expansion packers.

[0012] The coal and rock mass hydraulic cutting-fracturing-pressure relief-gas permeability enhancement treatment device provided by the present invention further includes: The orientation instrument is fixedly installed on the side of the jet injector away from the first packer. The orientation instrument is used to measure the spatial azimuth angle of the jet injector in the target borehole in real time. The orientation instrument is electrically connected to the control system. The guide head is fixedly installed on the side of the directional instrument away from the jet injector. The guide head is used to guide the treatment device of hydraulic grooving-fracturing depressurization-gas permeability enhancement in coal and rock mass as it moves along the target borehole.

[0013] According to the present invention, a hydraulic grooving-fracturing-pressure relief-gas permeability enhancement treatment device for coal and rock masses includes an ejector comprising: The main body is connected to the connector, and a flow channel connected to the first conveying pipeline is provided inside the main body. The nozzle is rotatably disposed on the body, and the axis of rotation of the nozzle relative to the body is parallel to the distribution direction of the jet injector and the first packer; The drive mechanism is located on the main body and is used to drive the nozzle to rotate relative to the main body. The drive mechanism is electrically connected to the control system.

[0014] This invention also provides a method for treating coal and rock masses using hydraulic grooving, fracturing, depressurization, and gas permeability enhancement. Based on the aforementioned device for treating coal and rock masses using hydraulic grooving, fracturing, depressurization, and gas permeability enhancement, the method includes: Based on the stress distribution characteristics of the mining face, the roof structure conditions, and the gas migration law, the location of the target borehole is determined. The target borehole can simultaneously meet the roof pressure relief conditions and the gas drainage conditions. The hydraulic grooving-fracturing-gas permeability enhancement treatment device for coal and rock mass is pushed to the target borehole, and the hydraulic grooving module of the hydraulic grooving-fracturing-gas permeability enhancement treatment device for coal and rock mass is made to correspond to the target borehole section of the target borehole. Cutting fluid is delivered to the jet injector of the hydraulic grooving module to jet-groove the target hole section of the target borehole; The position of the hydraulic grooving-fracturing-gas permeability enhancement treatment device for coal and rock mass is adjusted along the extension direction of the target borehole, so that the hydraulic fracturing module of the hydraulic grooving-fracturing-gas permeability enhancement treatment device corresponds to the target section of the target borehole, so as to use the first packer and the second packer of the hydraulic fracturing module to seal the target section of the target borehole and form a fracturing cavity; Fracturing fluid is supplied to the fracturing chamber to fracturing the target section of the target borehole; The gas drainage system is connected to the end of the target borehole, and gas drainage is performed to obtain a drainage mixture.

[0015] The method for treating coal and rock masses by hydraulic grooving, fracturing, depressurization, and gas permeability enhancement according to the present invention further includes: The extracted mixture is subjected to gas-liquid separation, and the gas portion and liquid portion are collected separately.

[0016] The present invention provides a treatment device for hydraulic grooving, fracturing, depressurization, and gas permeability enhancement in coal and rock masses, comprising a hydraulic grooving module, a hydraulic fracturing module, and connecting components. The hydraulic grooving module includes an ejector and a first delivery pipeline. A first end of the first delivery pipeline is connected to the ejector, and a second end is connected to a cutting fluid source. The first delivery pipeline can deliver cutting fluid to the ejector. The ejector is used to jet fluid into the target borehole section to cut grooves, completing the hydraulic grooving operation and creating an artificially weakened zone in the coal and rock mass of the target borehole section. The hydraulic fracturing module includes a first packer, a constant pressure opener, and a second packer, which are connected sequentially. The first and second packers are used to seal the target borehole section to form a fracturing cavity. The constant pressure opener allows fracturing fluid to be delivered into the fracturing cavity after the first and second packers have sealed the target borehole for fracturing operations. This process induces fractures in the coal and rock mass, which then expand to form a fracture network, achieving coal and rock mass fracturing and stress release. A connector is positioned between the jet injector and the first packer, used to connect the hydraulic grooving module and the hydraulic fracturing module. With this configuration, the coal and rock mass hydraulic grooving-fracturing decompression-gas permeability enhancement treatment device provided by this invention integrates the hydraulic grooving module and the hydraulic fracturing module into a tool string, possessing both hydraulic grooving and hydraulic fracturing functions. In actual operation, for operation on one target section within the target borehole, it is only necessary to push the coal and rock mass hydraulic grooving-fracturing decompression-gas permeability enhancement treatment device to the target section of the target borehole. First, the hydraulic grooving operation is completed by the hydraulic grooving module. Then, the position of the coal and rock mass hydraulic grooving-fracturing decompression-gas permeability enhancement treatment device is adjusted to complete the fracturing operation through the hydraulic fracturing module. For operations on other target borehole segments within the target borehole, only the position of the hydraulic grooving-fracturing decompression-gas permeability enhancement treatment device needs to be adjusted so that its hydraulic grooving and hydraulic fracturing modules correspond to the target borehole segments requiring operation. For operations within the same target borehole, the treatment device only needs to be inserted and removed once, eliminating the need for repeated insertion and removal. This simplifies operation, saves time, and improves the efficiency of roof decompression and gas drainage, thus solving the problem of low efficiency in roof decompression and gas drainage operations in related technologies. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the coal and rock mass hydraulic cutting-fracturing depressurization-gas permeability enhancement treatment device provided by the present invention when it is located inside the target borehole.

[0019] Figure 2 This is a schematic diagram of the structure of the coal and rock mass hydraulic cutting-fracturing depressurization-gas permeability enhancement treatment device provided by the present invention.

[0020] Figure 3 This is a flowchart of the coal and rock mass hydraulic cutting-fracturing depressurization-gas permeability enhancement treatment method provided by the present invention.

[0021] Figure label: 1. Ejector; 2. First delivery pipeline; 3. Target borehole; 4. Connector; 5. Drilling rig; 6. First packer; 7. Second packer; 8. Constant pressure opener; 9. Delivery pipe body; 10. Release mechanism; 11. Orientation instrument; 12. Guide head; 13. Main body; 14. Nozzle; 15. Water tank; 16. High-pressure pump. Detailed Implementation

[0022] 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 with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0023] The following is combined Figures 1 to 3 The present invention describes a coal and rock mass hydraulic cutting-fracturing depressurization-gas permeability enhancement treatment device.

[0024] like Figures 1 to 3 As shown, the coal and rock mass hydraulic grooving-fracturing depressurization-gas permeability enhancement treatment device provided in this embodiment of the invention includes a hydraulic grooving module, a hydraulic fracturing module, and a connector 4.

[0025] Specifically, the hydraulic grooving module includes an ejector 1 and a first delivery pipe 2. The first end of the first delivery pipe 2 is connected to the ejector 1, and the second end of the first delivery pipe 2 is used to connect to the cutting fluid source.

[0026] The first delivery pipeline 2 can deliver cutting fluid to the jet injector 1. The jet injector 1 is used to jet fluid into the target section of the target borehole 3 to cut the slot and complete the hydraulic grooving operation, so that the coal and rock mass of the target section of the target borehole 3 forms an artificial weakened zone.

[0027] The hydraulic fracturing module includes a first packer 6, a constant pressure initiator 8, and a second packer 7, which are connected sequentially. The first packer 6 and the second packer 7 are used to seal the target borehole section 3 to form a fracturing cavity. Specifically, both sides of the target borehole section 3 can be sealed respectively, and the space between the first packer 6 and the second packer 7 is the fracturing cavity.

[0028] The constant pressure initiator 8 is used to allow fracturing fluid to be delivered to the fracturing chamber for fracturing operations after the first packer 6 and the second packer 7 have completed the sealing of the target borehole 3. This causes fractures to be generated in the coal and rock mass, which then expand to form a fracture network, achieving coal and rock mass fracturing and stress release.

[0029] The connector 4 is located between the jet injector 1 and the first packer 6. The connector 4 is used to connect the hydraulic grooving module and the hydraulic fracturing module together.

[0030] With this configuration, the hydraulic grooving-fracturing-gas permeability enhancement processing device for coal and rock mass provided in this embodiment of the invention integrates the hydraulic grooving module and the hydraulic fracturing module into a tool string, possessing both hydraulic grooving and hydraulic fracturing functions. In actual operation, for the operation of one target borehole segment within the target borehole 3, it is only necessary to transport the hydraulic grooving-fracturing-gas permeability enhancement processing device to the target borehole segment of the target borehole 3. First, the hydraulic grooving operation is completed through the hydraulic grooving module. Then, the position of the hydraulic grooving-fracturing-gas permeability enhancement processing device is adjusted so that the fracturing operation is completed through the hydraulic fracturing module. For the operation of the remaining target borehole segments within the target borehole 3, it is only necessary to adjust the position of the hydraulic grooving-fracturing-gas permeability enhancement processing device so that the hydraulic grooving module and the hydraulic fracturing module of the device correspond to the target borehole segments requiring operation. For operations within the same target borehole 3, only one insertion and one removal of the treatment device for hydraulic grooving, fracturing, depressurization, and gas permeability enhancement of the coal and rock mass is required. There is no need for repeated insertion and removal, which simplifies the operation, saves time, and helps improve the efficiency of roof depressurization and gas drainage operations. This solves the problem of low efficiency in roof depressurization and gas drainage operations in related technologies.

[0031] The connection structure between the jet injector 1 and the connector 4 can be achieved through a threaded connection.

[0032] In this embodiment of the invention, the first packer 6 has a first support tube body, with a closed first end and an open second end. The first end of the first support tube body is threadedly connected to the connector 4, meaning that the jet injector 1 is fixedly mounted to the first end of the first support tube body via the connector 4. This achieves the connection between the first packer 6 and the hydraulic grooving module.

[0033] The constant pressure opener 8 has a second support tube with open ends. The first end of the second support tube is threaded to the second end of the first support tube, thus connecting the constant pressure opener 8 to the first packer 6.

[0034] The second packer 7 has a third support tube with open ends. The first end of the third support tube is threaded to the second end of the second support tube, thus connecting the second packer 7 to the constant pressure opener 8.

[0035] The first conveying pipe 2 passes through the interior of the third support pipe, the second support pipe, and the first support pipe, and passes through the first end of the first support pipe and is sealed. There is a gap between the outer wall of the first conveying pipe 2 and the inner wall of the first support pipe, the second support pipe, and the third support pipe.

[0036] With this configuration, cutting fluid is delivered through the inner cavity of the first delivery pipe 2, and fracturing fluid is delivered through the gaps between the first delivery pipe 2 and the first support pipe, the gap between the first delivery pipe 2 and the second support pipe, and the gap between the first delivery pipe 2 and the third support pipe. Integrating the first delivery pipe 2 of the hydraulic grooving module with the delivery channel of the hydraulic fracturing module simplifies the external piping structure of the coal and rock mass hydraulic grooving-fracturing depressurization-gas permeability enhancement treatment device.

[0037] The side wall of the second support tube is provided with a flow passage, which connects the inner cavity of the second support tube to the fracturing chamber. This allows the fracturing fluid to flow precisely from the inside of the second support tube to the fracturing chamber, achieving precise fracturing of the target borehole section 3.

[0038] A control valve is installed at the location of the flow passage. The control valve is used to open the flow passage after the first packer 6 and the second packer 7 have completed the sealing of the target borehole 3. If the first packer 6 and the second packer 7 have not completed the sealing, the control valve closes the flow passage to prevent the fracturing fluid from flowing out of the second support tube and avoid leakage of the fracturing fluid.

[0039] In this embodiment, the first packer 6 and the second packer 7 are hydraulic expansion packers.

[0040] The hydraulic expansion packer has rubber bladders, with rubber bladders installed on the exterior of both the first and third support tubes. The first support tube has a connecting hole for fluid to flow from its interior to the inner cavity of the rubber bladder. Similarly, the third support tube has a connecting hole for fluid to flow from its interior to the inner cavity of the rubber bladder. By filling the rubber bladders with fluid, they expand radially under internal pressure, tightly adhering to the wall of the target borehole, thus forming a seal.

[0041] The first support tube of the first packer 6, the second support tube of the constant pressure initiator 8, and the third support tube of the second packer 7 are connected. The first packer 6, the second packer 7, and the fracturing chamber share the same fluid, which simplifies the fluid piping. That is, the target borehole 3 is sealed by filling the inner cavity of the rubber bladder of the first packer 6 and the inner cavity of the rubber bladder of the second packer 7 with fracturing fluid.

[0042] At this time, the control valve of the constant pressure initiator 8 is set to open the flow orifice when the fluid pressure in the second support tube is greater than the preset pressure. Before the pressure of the fracturing fluid in the second support tube reaches the preset pressure, the flow orifice is closed, and the fracturing fluid will enter the first packer 6 and the second packer 7.

[0043] The pressure of the fracturing fluid in the third support tube is the same as the pressure of the fracturing fluid in the first packer 6 and the second packer 7. When the pressure of the fracturing fluid in the first packer 6 and the fracturing fluid in the second packer 7 reaches the preset pressure, the radial expansion deformation of the first packer 6 and the second packer 7 can meet the sealing requirements.

[0044] Continue to inject fracturing fluid into the third support tube. The pressure of the fracturing fluid in the third support tube continues to increase. When the pressure of the fracturing fluid exceeds the preset pressure, the flow hole of the constant pressure opener 8 is opened, and the fracturing fluid flows into the fracturing chamber.

[0045] In a further embodiment, the coal and rock mass hydraulic cutting-fracturing depressurization-gas permeability enhancement treatment device also includes a second conveying pipeline.

[0046] The second delivery pipeline is located on the side of the second packer 7 away from the ejector 1. The first end of the second delivery pipeline is connected to the second end of the third support pipe. The second end of the second delivery pipeline is used to connect to the fracturing fluid source and to supply the fracturing fluid from the fracturing fluid source to the hydraulic fracturing module.

[0047] The first conveying pipe 2 passes through the interior of the second conveying pipe, and there is a gap between the outer wall of the first conveying pipe 2 and the inner wall of the second conveying pipe.

[0048] The gap between the outer wall of the first delivery pipeline 2 and the inner wall of the second delivery pipeline cleverly forms a channel for delivering fracturing fluid. The cutting fluid is delivered through the inner cavity of the first delivery pipeline 2, and the fracturing fluid is delivered through the gap channel between the outer wall of the first delivery pipeline 2 and the inner wall of the second delivery pipeline, thus realizing the independent delivery of the two functional fluids in the same device.

[0049] This makes the structure of the entire coal and rock mass hydraulic grooving-fracturing depressurization-gas permeability enhancement treatment device more compact, enabling the integrated layout of two different functional fluid pipelines within a limited borehole space, providing a basis for continuously completing grooving and fracturing operations in a single well run.

[0050] The second delivery pipeline includes at least two delivery pipe sections 9. Any two delivery pipe sections 9 can be connected by threads to allow any number of delivery pipe sections 9 to be connected in series. Any delivery pipe section 9 can be threaded to the second end of the third support pipe. The number of delivery pipe sections 9 connected in series is determined based on the position of the target hole segment of the target borehole 3.

[0051] After connecting the required number of delivery pipes 9 together, the end of the delivery pipe 9 is threaded to the second end of the third support pipe. The other end of the delivery pipe 9 is connected to the fracturing fluid source and placed on the drilling rig 5, so that the drilling rig 5 can deliver the second delivery pipeline to the target hole section of the target borehole 3.

[0052] In this embodiment, the first delivery pipeline 2 is a flexible hose, which facilitates its installation and layout within the second delivery pipeline, the third support pipe, the second support pipe, and the first support pipe, simplifying the assembly difficulty and complexity of the device.

[0053] The conveying pipe 9 is a rigid pipe, which can provide sufficient axial thrust and rigidity to ensure that the hydraulic grooving-fracturing and depressurization-gas permeability enhancement treatment device for coal and rock mass is smoothly pushed to the target section of the target borehole 3, ensuring the reliability of the pushing process and the stability of the posture after the device is pushed into place.

[0054] The material of the conveying pipe 9 can be, but is not limited to, iron.

[0055] The second conveying pipeline also includes a release mechanism 10, which is disposed between the first end of the second conveying pipeline and the second end of the third support pipe. The first end of the second conveying pipeline and the second end of the third support pipe are connected by the release mechanism 10. One end of the release mechanism 10 is threadedly connected to the second end of the third support pipe, and the other end of the release mechanism 10 is threadedly connected to the first end of the second conveying pipeline.

[0056] The release mechanism 10 is an emergency unlocking function. When the hydraulic fracturing module and the hydraulic grooving module are blocked for any reason, the second delivery pipeline can be disconnected from the hydraulic fracturing module through the release mechanism 10, so that the second delivery pipeline can be retrieved and reused. This avoids the problem of the entire coal and rock hydraulic grooving-fracturing pressure relief-gas permeability enhancement treatment device being scrapped, reduces potential economic losses and accident handling difficulties, and improves the safety and fault tolerance of the operation.

[0057] The release mechanism 10 may be configured as a shear pin type release mechanism, a hydraulic release mechanism, a threaded release joint, or an electromagnetic or intelligent release mechanism.

[0058] The release mechanism 10 comprises two separable parts, one part being threadedly connected to the second end of the third support pipe, and the other part being threadedly connected to the first end of the second delivery pipeline. Normally, these two parts are connected together. If the hydraulic fracturing module and the hydraulic grooving module become jammed, a series of operations can separate these two parts, thereby separating the second delivery pipeline from the hydraulic fracturing module.

[0059] In a further embodiment, the treatment device for hydraulic grooving, fracturing, depressurization, and gas permeability enhancement in coal and rock mass also includes an orienting instrument 11 and a guide head 12.

[0060] The orientation instrument 11 is fixedly installed on the side of the jet injector 1 away from the first packer 6. The orientation instrument 11 is used to measure the spatial azimuth angle of the jet injector 1 in the target borehole 3 in real time. The orientation instrument 11 is electrically connected to the control system.

[0061] The orientation information of the jet injector 1 can be obtained in real time through the orientation instrument 11, which is convenient for determining the expected cutting direction and assisting in the orientation control of directional cutting. This ensures that the hydraulic cutting module performs precise operations in the preset direction, thereby guaranteeing the effect of subsequent roof depressurization or gas extraction and improving the controllability and accuracy of the entire process.

[0062] The guide head 12 is fixedly installed on the side of the orienting instrument 11 away from the jet injector 1. The guide head 12 is used to guide the hydraulic cutting-fracturing-gas permeability enhancement treatment device of the coal and rock mass along the target borehole 3. It can effectively guide the hydraulic cutting-fracturing-gas permeability enhancement treatment device of the coal and rock mass through the curved or irregular sections in the target borehole 3, avoid the device getting stuck during the pushing process, and ensure that the device can reach the target section smoothly and quickly, thus improving construction efficiency and safety.

[0063] In this embodiment of the invention, the jet ejector 1 includes a body part 13, a nozzle part 14, and a drive mechanism.

[0064] The main body 13 is connected to the connector 4, and a flow channel connected to the first delivery pipe 2 is provided inside the main body 13. The nozzle 14 is connected to the flow channel, which provides a passage for the cutting fluid to flow from the first delivery pipe 2 to the nozzle 14.

[0065] The nozzle section 14 is rotatably disposed on the body section 13, and the axis of rotation of the nozzle section 14 relative to the body section 13 is parallel to the distribution direction of the jet injector 1 and the first packer 6. A drive mechanism is disposed on the body section 13, and the drive mechanism is used to drive the nozzle section 14 to rotate relative to the body section 13. The drive mechanism is electrically connected to the control system.

[0066] By rotating the nozzle section 14, jets can be applied to various circumferential positions of the target borehole 3.

[0067] During hydraulic grooving operations, directional grooving or rotary grooving can be performed as required.

[0068] During directional grooving, the rotation angle of the nozzle section 14 is adjusted according to the grooving direction so that the nozzle section 14 can jet in the designed direction. During the grooving process, the nozzle section 14 remains relatively fixed to the body section 13. In this way, a straight groove can be obtained.

[0069] During rotary grooving, the nozzle section 14 can be controlled to continuously rotate relative to the main body to jet grooving at various circumferential positions of the target borehole 3. In this way, circumferential grooves or spiral grooves can be obtained.

[0070] The rotation axis of the nozzle section 14 relative to the body section 13 is parallel to the distribution direction of the jet injector 1 and the first packer 6. In a further embodiment, each nozzle of the nozzle section 14 can be configured as a rotatable structure. Specifically, the rotation axis of each nozzle of the nozzle section 14 can be perpendicular to the distribution direction of the jet injector 1 and the first packer 6, which can increase the jet direction range of the nozzle section 14 and achieve jetting in different directions without replacing the jet injector 1.

[0071] On the other hand, the present invention also provides a method for treating coal and rock masses using hydraulic cutting, fracturing, depressurization, and gas permeability enhancement based on the coal and rock mass hydraulic cutting, fracturing, depressurization, and gas permeability enhancement treatment device provided in any of the above embodiments. The coal and rock mass hydraulic cutting, fracturing, depressurization, and gas permeability enhancement treatment method described below can be referred to in correspondence with the coal and rock mass hydraulic cutting, fracturing, depressurization, and gas permeability enhancement treatment device described above.

[0072] like Figure 3 As shown, the coal and rock mass hydraulic cutting-fracturing depressurization-gas permeability enhancement method provided in this embodiment of the invention includes steps 110 to 160.

[0073] Step 110: Based on the stress distribution characteristics of the mining face, the roof structure conditions, and the gas migration law, determine the location of the target borehole. The target borehole should be able to simultaneously meet the roof pressure relief conditions and the gas drainage conditions.

[0074] Step 120: Push the hydraulic grooving-fracturing-gas permeability enhancement treatment device for coal and rock mass to the target borehole, and make the hydraulic grooving module of the hydraulic grooving-fracturing-gas permeability enhancement treatment device correspond to the target section of the target borehole.

[0075] Step 130: Supply cutting fluid to the jetter of the hydraulic grooving module to jet groove the target hole section of the target borehole.

[0076] Step 140: Adjust the position of the hydraulic cutting-fracturing-gas permeability enhancement treatment device along the extension direction of the target borehole, so that the hydraulic fracturing module of the hydraulic cutting-fracturing-gas permeability enhancement treatment device corresponds to the target borehole section of the target borehole, so as to use the first and second packers of the hydraulic fracturing module to seal the target borehole section of the target borehole and form a fracturing cavity.

[0077] Step 150: Fracturing fluid is delivered to the fracturing chamber to fracture the target section of the target borehole.

[0078] Step 160: Connect the gas drainage system to the end of the target borehole and perform gas drainage to obtain a drainage mixture.

[0079] This invention employs a coal and rock mass hydraulic grooving-fracturing depressurization-gas permeability enhancement treatment device integrating a hydraulic grooving module and a hydraulic fracturing module to treat the coal and rock mass. The treatment of the coal and rock mass includes roof depressurization and gas drainage.

[0080] Based on the stress distribution characteristics of the mining face, the roof structure conditions, and the gas migration law, the location of target borehole 3 is determined. Target borehole 3 can simultaneously meet the roof pressure relief conditions and the gas drainage conditions.

[0081] In this way, a single target borehole 3 can simultaneously serve two purposes: roof pressure relief and gas drainage, achieving multiple uses for one borehole. Compared with the traditional method of drilling boreholes separately for different purposes, this simplifies the construction process, helps reduce the number of boreholes, shortens the operation time, and reduces the operating cost.

[0082] After the hydraulic grooving-fracturing-gas permeability enhancement treatment device for coal and rock mass is pushed to the target section of the target borehole 3, its function can be switched simply by adjusting its position along the extension direction of the target borehole 3. For operations within the same target borehole 3, the hydraulic grooving-fracturing-gas permeability enhancement treatment device only needs to be placed and removed once, eliminating the need to repeatedly place and retrieve different tools between hydraulic grooving and hydraulic fracturing operations. This simplifies the on-site operation process, avoids the time-consuming process of repeatedly placing and retrieving tools, saves operation time, and improves the efficiency of roof depressurization and gas drainage operations, solving the problem of low efficiency in roof depressurization and gas drainage operations in related technologies.

[0083] The derivation process of the beneficial effects of the hydraulic grooving-fracturing-pressure relief-gas permeability enhancement treatment method for coal and rock mass in this embodiment of the invention is largely similar to the derivation process of the beneficial effects of the hydraulic grooving-fracturing-pressure relief-gas permeability enhancement treatment device for coal and rock mass described above, so it will not be repeated here.

[0084] For top plate decompression, after step 150 is completed, the stress release at the target hole section of the target borehole 3 is completed.

[0085] For gas drainage, after step 150, only the permeability enhancement operation of the coal and rock mass in the target section of target borehole 3 has been completed, improving the permeability of the coal and rock mass. After step 150, it is necessary to connect the gas drainage system to the end of target borehole 3 and perform gas drainage to obtain a drainage mixture. The drainage mixture is then subjected to gas-liquid separation, collecting the gas and liquid portions separately. Through gas-liquid separation, high-concentration gas can be metered, purified, and utilized for resource recovery, combining safety management with economic benefits. Furthermore, the extracted fracturing fluid, groundwater, and other liquids can be collected and treated harmlessly, avoiding underground water pollution and achieving safe, efficient, and environmentally friendly coal mining.

[0086] The cutting fluid mentioned above can be clean water or abrasive water.

[0087] The fracturing fluid mentioned above can be, but is not limited to, clean water.

[0088] In this specific embodiment, both the cutting fluid and the fracturing fluid are clean water, stored in a water tank 15, which serves as both the source of the cutting fluid and the source of the fracturing fluid. A high-pressure pump 16 is connected to the water tank 15. The high-pressure pump 16 has two inlets, and the pumping of clean water to either inlet is controllable. A first delivery pipeline 2 extends from the second delivery pipeline and connects to one inlet of the high-pressure pump 16. The end of the second delivery pipeline connects to the other inlet of the high-pressure pump 16.

[0089] In summary, the coal and rock mass hydraulic grooving-fracturing decompression-gas permeability enhancement treatment device and method provided in this embodiment of the invention integrates the functions of hydraulic grooving and hydraulic fracturing, avoiding frequent tool handling and achieving process synergy. Hydraulic grooving, fracturing decompression, and gas drainage mutually promote each other, improving the overall treatment effect. Furthermore, the coal and rock mass hydraulic grooving-fracturing decompression-gas permeability enhancement treatment method provided in this embodiment of the invention also achieves multi-purpose use of a single borehole, integrating roof decompression and gas drainage functions within the same target borehole 3, reducing the number of boreholes and lowering construction costs.

[0090] The hydraulic grooving-fracturing-gas permeability enhancement device and method for coal and rock mass provided in this embodiment can effectively weaken the structure of thick and hard coal and rock mass, reduce the stress concentration of the roof, and reduce the intensity of mine pressure manifestation. It can also improve gas drainage efficiency, increase the permeability of coal and rock mass, and expand the gas drainage radius.

[0091] Moreover, the treatment device and method for hydraulic grooving, fracturing and depressurization, and gas permeability enhancement of coal and rock mass provided in this embodiment have a reasonable structure, clear process, and strong operability. They have good safety benefits, economic benefits, and promotion and application value, and can be applied to the comprehensive disaster management of thick and hard roof, high gas, and low permeability coal seams.

[0092] 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 of the technical features; and these 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 treatment device for hydraulic grooving, fracturing, depressurization, and gas permeability enhancement in coal and rock masses, characterized in that, include: The hydraulic grooving module includes an ejector (1) and a first delivery pipe (2). The first end of the first delivery pipe (2) is connected to the ejector (1), and the second end of the first delivery pipe (2) is used to connect to a cutting fluid source. The ejector (1) is used to jet fluid into the target hole section of the target borehole (3) to cut the groove. The hydraulic fracturing module includes a first packer (6), a constant pressure opener (8), and a second packer (7) connected in sequence. The first packer (6) and the second packer (7) are used to seal the target borehole (3) to form a fracturing cavity. The constant pressure opener (8) is used to allow fracturing fluid to be delivered to the fracturing cavity after the first packer (6) and the second packer (7) have completed sealing the target borehole (3). A connector (4) is disposed between the jet injector (1) and the first packer (6). The connector (4) is used to connect the hydraulic grooving module and the hydraulic fracturing module together.

2. The coal and rock mass hydraulic cutting-fracturing depressurization-gas permeability enhancement treatment device according to claim 1, characterized in that, The first packer (6) has a first support tube body, the first end of the first support tube body is closed, the second end of the first support tube body is open, and the first end of the first support tube body is threadedly connected to the connector (4). The constant pressure opener (8) has a second support tube body, both ends of the second support tube body are open, and the first end of the second support tube body is threadedly connected to the second end of the first support tube body; The second packer (7) has a third support tube, the two ends of which are open, and the first end of the third support tube is threadedly connected to the second end of the second support tube; The first conveying pipe (2) passes through the interior of the third support pipe, the second support pipe and the first support pipe. The first conveying pipe (2) passes through the first end of the first support pipe and is sealed. There is a gap between the outer wall of the first conveying pipe (2) and the inner wall of the first support pipe, the second support pipe and the third support pipe.

3. The coal and rock mass hydraulic cutting-fracturing depressurization-gas permeability enhancement treatment device according to claim 2, characterized in that, Also includes: The second delivery pipeline is located on the side of the second packer (7) away from the jet injector (1). The first end of the second delivery pipeline is connected to the second end of the third support pipe. The second end of the second delivery pipeline is used to connect to the fracturing fluid source. The first delivery pipeline (2) passes through the interior of the second delivery pipeline. There is a gap between the outer wall of the first delivery pipeline (2) and the inner wall of the first delivery pipeline.

4. The coal and rock mass hydraulic cutting-fracturing depressurization-gas permeability enhancement treatment device according to claim 3, characterized in that, The second delivery pipeline includes: At least two conveying pipe sections (9) are provided, any two of the conveying pipe sections (9) can be connected by threads, and any one of the conveying pipe sections (9) can be connected by threads to the second end of the third support pipe.

5. The treatment device for hydraulic grooving, fracturing, depressurization, and gas permeability enhancement in coal and rock mass according to claim 3, characterized in that, The first conveying pipeline (2) is a flexible hose, the second conveying pipeline is a rigid pipe, and the coal and rock hydraulic grooving-fracturing depressurization-gas permeability enhancement treatment device further includes: The release mechanism (10) is disposed between the first end of the second conveying pipeline and the second end of the third support pipe. One end of the release mechanism (10) is threadedly connected to the second end of the third support pipe, and the other end of the release mechanism (10) is threadedly connected to the first end of the second conveying pipeline.

6. The coal and rock mass hydraulic grooving-fracturing depressurization-gas permeability enhancement treatment device according to claim 1, characterized in that, The first packer (6) and the second packer (7) are hydraulic expansion packers.

7. The treatment device for hydraulic grooving, fracturing, depressurization, and gas permeability enhancement of coal and rock mass according to any one of claims 1-6, characterized in that, Also includes: The orientation instrument (11) is fixedly installed on the side of the jet injector (1) away from the first packer (6). The orientation instrument (11) is used to measure the spatial azimuth angle of the jet injector (1) in the target borehole (3) in real time. The orientation instrument (11) is electrically connected to the control system. The guide head (12) is fixedly installed on the side of the orienting instrument (11) away from the jet (1). The guide head (12) is used to guide the coal and rock hydraulic cutting-fracturing depressurization-gas permeability enhancement treatment device as it moves along the target borehole (3).

8. The treatment device for hydraulic grooving, fracturing, depressurization, and gas permeability enhancement of coal and rock mass according to any one of claims 1-6, characterized in that, The jet ejector (1) includes: The main body (13) is connected to the connector (4), and the main body (13) is provided with a flow channel connected to the first conveying pipeline (2); The nozzle part (14) is rotatably disposed on the body part (13), and the rotation axis of the nozzle part (14) relative to the body part (13) is parallel to the distribution direction of the jet (1) and the first packer (6); A drive mechanism is provided on the body part (13). The drive mechanism is used to drive the nozzle part (14) to rotate relative to the body part (13). The drive mechanism is electrically connected to the control system.

9. A method for treating coal and rock masses using hydraulic grooving, fracturing, depressurization, and gas permeability enhancement, characterized in that... Based on the coal and rock mass hydraulic cutting-fracturing depressurization-gas permeability enhancement treatment device as described in any one of claims 1 to 8, the coal and rock mass hydraulic cutting-fracturing depressurization-gas permeability enhancement treatment method includes: Based on the stress distribution characteristics of the mining face, the roof structure conditions, and the gas migration law, the location of the target borehole is determined. The target borehole can simultaneously meet the roof pressure relief conditions and the gas drainage conditions. The hydraulic grooving-fracturing-gas permeability enhancement treatment device for coal and rock mass is pushed to the target borehole, and the hydraulic grooving module of the hydraulic grooving-fracturing-gas permeability enhancement treatment device for coal and rock mass is made to correspond to the target borehole section of the target borehole. Cutting fluid is delivered to the jet injector of the hydraulic grooving module to jet-groove the target hole section of the target borehole; The position of the hydraulic grooving-fracturing-gas permeability enhancement treatment device for coal and rock mass is adjusted along the extension direction of the target borehole, so that the hydraulic fracturing module of the hydraulic grooving-fracturing-gas permeability enhancement treatment device corresponds to the target section of the target borehole, so as to use the first packer and the second packer of the hydraulic fracturing module to seal the target section of the target borehole and form a fracturing cavity; Fracturing fluid is supplied to the fracturing chamber to fracturing the target section of the target borehole; The gas drainage system is connected to the end of the target borehole, and gas drainage is performed to obtain a drainage mixture.

10. The method for treating coal and rock masses using hydraulic grooving, fracturing, depressurization, and gas permeability enhancement according to claim 9, characterized in that, Also includes: The extracted mixture is subjected to gas-liquid separation, and the gas portion and liquid portion are collected separately.

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