Coal seam hydraulic slotting device

Abstract

The utility model provides a coal seam hydraulic slotting device which comprises a drill rod and a slotting device arranged at the front end of the drill rod, a high-pressure water tail is arranged at the rear end of the drill rod, the static end of the high-pressure water tail is fixedly connected with a high-pressure hose, the rotating end of the high-pressure water tail is fixedly connected with a main shaft of a drilling machine, and the slotting device is arranged at the front end of the drill rod. A drill bit is arranged at the front end of the slotting device, a plurality of nozzles are detachably arranged on the outer wall of the slotting device in the circumferential direction, a high-pressure water pipe is connected with a high-pressure water pump to inject high-pressure water into a drill rod, a drilling machine drives the drill rod to rotationally drill, and the high-pressure water enters the slotting device through the drill rod and is rotationally ejected out through the nozzles to slot a coal seam. The hydraulic seam cutting device for the coal seam can be used for fully cutting the coal seam under different geological conditions, and is simple in operation, low in operation intensity and low in potential safety hazard.

Description

Technical Field

[0001] This utility model belongs to the field of coal seam fracturing technology, and in particular relates to a coal seam hydraulic fracturing device. Background Technology

[0002] An isolated working face refers to a working face in coal mining where the area to be mined is surrounded by goaf. Isolated working faces challenges such as high stress concentration, difficulty in roof management, complex gas control, and difficulty in water hazard prevention. Traditional mechanical cutting technology is prone to sparking and severe equipment wear in hard coal seams and high-gas coal seams, increasing mining difficulty and safety risks. Moreover, traditional mechanical cutting requires multiple protections such as gas monitoring and dust suppression spraying, lacks flexibility, and is difficult to move under complex geological conditions, making it difficult to meet mining needs, resulting in slow advance speed or even production stoppage. Summary of the Invention

[0003] In view of this, the present invention aims to propose a hydraulic fracturing device for coal seams to solve the problems of high difficulty, high risk and poor equipment adaptability in mining under complex geological conditions using traditional technologies.

[0004] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0005] A hydraulic slitting device for coal seams includes a drill rod and a slitting device at its front end. A high-pressure water tail is provided at the rear end of the drill rod. The stationary end of the high-pressure water tail is fixedly connected to a high-pressure hose. The rotating end of the high-pressure water tail is fixedly connected to the main shaft of the drilling rig. A slitting device is provided at the front end of the drill rod. A drill bit is provided at the front end of the slitting device. Multiple nozzles are detachably provided on the outer wall of the slitting device along the circumferential direction.

[0006] Furthermore, the slitting device includes a slitting device body, which includes a first sealing section and a second sealing section. The first sealing section and the second sealing section are integral structures. The first sealing section is provided with a first insertion cavity and a second insertion cavity in sequence along the axial direction. The first insertion cavity is provided with an internal thread. The second sealing section is provided with a first insertion part and a second insertion part in sequence along the axial direction. The first insertion part and the second insertion part are integral structures. The first insertion part is provided with an external thread. The front end of the drill rod is threadedly connected to the first insertion cavity, and the rear end of the drill bit is threadedly connected to the first insertion part.

[0007] Furthermore, the first sealing section is provided with a first cavity, and the second sealing section is provided with a second cavity. The first cavity is a stepped hole, and the second cavity is connected to the small-diameter end of the first cavity, and the inner diameter of the second cavity is larger than the inner diameter of the small-diameter end of the first cavity.

[0008] Furthermore, the sidewall of the first sealing section is provided with a plurality of mounting holes along the circumference, each mounting hole being connected to the large-diameter end of the first cavity, and a nozzle being provided on each mounting hole.

[0009] Furthermore, the slit cutting device also includes a positioning valve assembly, which is used to form an end face seal of the first cavity. The positioning valve assembly includes a guide post and a compression spring. The guide post has a T-shaped cross-section. The outer periphery of the rear end of the guide post abuts against the inner wall of the large-diameter end of the first cavity, and the outer periphery of the rear end of the guide post can coincide with the mounting hole. The outer periphery of the front end of the guide post abuts against the inner wall of the small-diameter end of the first cavity. The compression spring is sleeved on the outer periphery of the guide post, and one end of the compression spring abuts against the rear end of the guide post and the other end abuts against the side wall of the first cavity.

[0010] Furthermore, the positioning valve assembly also includes a limiting member, which is detachably connected to the front end of the guide post. The limiting member is located in the second cavity and can abut against the end face of the first cavity.

[0011] Furthermore, a sealing gasket is provided around the rear periphery of the guide post in the circumferential direction, and multiple sealing rings are provided around the guide post located at the small diameter end of the first cavity.

[0012] Furthermore, the drill rod includes a middle section and a first connecting section and a second connecting section respectively provided at both ends. The middle section, the first connecting section and the second connecting section are integral structures. The first connecting section is provided with a third insertion cavity and a fourth insertion cavity in sequence along the axial direction. The third insertion cavity is provided with internal threads. The second connecting section is provided with a third insertion part and a fourth insertion part in sequence along the axial direction. The third insertion part is provided with external threads and is threadedly connected to the first insertion cavity. The fourth insertion cavity and the fourth insertion part are respectively provided with shrinkage channels. The middle section is provided with a cylindrical hole. The shrinkage channel and the cylindrical hole are coaxially arranged. The inner diameter of the cylindrical hole is larger than the inner diameter of the shrinkage channel.

[0013] Furthermore, multiple sealing rings are respectively provided on the periphery of the fourth and second plug-in parts, and the sealing rings are used to ensure a tight seal at the connection.

[0014] Furthermore, the nozzle has a jet hole and multiple converging holes. The jet hole is located at the top of the nozzle, and the converging holes are located at the bottom of the nozzle. The inner ring area of ​​the jet hole end is smaller than the sum of the inner ring areas of the multiple converging holes ends. A tapered groove is provided at the end of the jet hole. The tapered groove is used to control the jet angle. The outer periphery of the nozzle is threadedly connected to the mounting hole.

[0015] Compared with the prior art, the slit-cutting device of this utility model has the following advantages:

[0016] (1) The coal seam hydraulic cutting device of this utility model injects high-pressure water into the drill rod through the connection of the high-pressure water tail and the high-pressure water pump. The drill rod is driven to rotate and feed through the drilling machine. The high-pressure water enters the cutting device through the drill rod and is ejected through the nozzle to cut the coal seam. Cutting can be carried out at the same time as drilling, which improves the work efficiency. By controlling the drilling progress of the drilling machine and the high-pressure water pressure, the coal seam can be fully cut under different geological conditions. The operation is simple, the work intensity is low, and the safety hazards are low.

[0017] (2) The coal seam hydraulic cutting device described in this utility model can control the flow of high pressure water by using a positioning valve assembly and controlling the pressure of the high pressure water to move the guide column. This allows drilling to be carried out under a certain low pressure and water jet cutting under high pressure, which can better adapt to complex geological conditions. Attached Figure Description

[0018] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings:

[0019] Figure 1 This is a schematic diagram of the structure of a coal seam hydraulic slotting device according to an embodiment of the present utility model;

[0020] Figure 2 This is a schematic cross-sectional view of a coal seam hydraulic slitting device according to an embodiment of the present utility model;

[0021] Figure 3 This is a schematic cross-sectional view of the slit-cutting device described in an embodiment of the present invention;

[0022] Figure 4 This is a schematic cross-sectional view of the drill pipe according to an embodiment of the present utility model;

[0023] Figure 5 This is a schematic diagram of the nozzle structure according to an embodiment of the present utility model;

[0024] Figure 6 This is a schematic cross-sectional view of the slit cutter body and nozzle according to an embodiment of the present utility model.

[0025] Explanation of reference numerals in the attached figures:

[0026] 1-Drill rod; 2-Slot cutting device; 3-Drill bit; 4-High-pressure water tail; 5-Nozzle; 6-High-pressure hose; 11-First connecting section; 12-Second connecting section; 13-Intermediate section; 21-Slot cutter body; 22-Positioning valve assembly; 211-First sealing section; 212-Second sealing section; 213-First cavity; 214-Second cavity; 215-Mounting hole; 221-Guide post; 222-Compression spring; 223-Limiting element; 51-Conical groove. Detailed Implementation

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments of the present invention can be combined with each other.

[0028] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0029] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0030] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0031] like Figure 1-6The diagram illustrates a hydraulic coal seam slitting device 2, comprising a drill rod 1 and a slitting device 2 at its front end. A high-pressure water jet 4 is located at the rear end of the drill rod 1. The high-pressure water jet 4 is a prior art model, GH05. The stationary end of the high-pressure water jet 4 is fixedly connected to a high-pressure hose 6, and the rotating end of the high-pressure water jet 4 is fixedly connected to the drill rig spindle. The slitting device 2 is located at the front end of the drill rod 1, and a drill bit 3 is located at the front end of the slitting device 2. Multiple nozzles 5 are detachably mounted circumferentially on the outer wall of the slitting device 2. The high-pressure water jet 4 is the connecting component between the drill rod 1 and the high-pressure water hose 6. The drill rig drives the drill rod 1 to rotate and drill. The high-pressure water hose 6 is connected to a high-pressure water pump that injects high-pressure water into the drill rod 1. The high-pressure water enters the slitting device 2 through the drill rod 1 and is then ejected through the rotating nozzles 5 to slit the coal seam.

[0032] like Figure 2 and Figure 3 As shown, the slitting device 2 includes a slitting device body 21, which includes a first sealing section 211 and a second sealing section 212. The first sealing section 211 and the second sealing section 212 are integral structures. The first sealing section 211 has a first insertion cavity and a second insertion cavity arranged sequentially along the axial direction. The first insertion cavity is provided with an internal thread. The second sealing section 212 has a first insertion part and a second insertion part arranged sequentially along the axial direction. The first insertion part and the second insertion part are integral structures. The first insertion part is provided with an external thread. The front end of the drill rod 1 is threadedly connected to the first insertion cavity. The rear end of the drill bit 3 is threadedly connected to the first insertion part; the first sealing section 211 has a first cavity 213, and the second sealing section 212 has a second cavity 214. The first cavity 213 is a stepped hole, and the second cavity 214 is connected to the small-diameter end of the first cavity 213, and the inner diameter of the second cavity 214 is larger than the inner diameter of the small-diameter end of the first cavity 213; the side wall of the first sealing section 211 has a plurality of mounting holes 215 along the circumferential direction, each mounting hole 215 is connected to the large-diameter end of the first cavity 213, and a nozzle 5 is provided on each mounting hole 215; Figure 4 As shown, the drill rod 1 includes a middle section 13 and a first connecting section 11 and a second connecting section 12 respectively provided at its two ends. The middle section 13, the first connecting section 11, and the second connecting section 12 are integral structures. The first connecting section 11 has a third insertion cavity and a fourth insertion cavity arranged sequentially along the axial direction. The third insertion cavity is provided with an internal thread. The second connecting section 12 has a third insertion part and a fourth insertion part arranged sequentially along the axial direction. The third insertion part is provided with an external thread and is threadedly connected to the first insertion cavity. The fourth insertion cavity and the fourth insertion part are respectively provided with a shrinkage channel. The middle section 13 has a cylindrical hole. The shrinkage channel and the cylindrical hole are coaxially arranged. The inner diameter of the cylindrical hole is larger than the inner diameter of the shrinkage channel. Multiple sealing rings are respectively provided on the periphery of the fourth insertion part and the second insertion part. The sealing rings are used to seal the connection tightly. Figure 5 and Figure 6As shown, the nozzle 5 has a jet hole and multiple converging holes. The jet hole is located at the top of the nozzle 5 and the converging holes are located at the bottom of the nozzle 5. The inner ring area of ​​the jet hole end is smaller than the sum of the inner ring areas of the multiple converging holes ends. A tapered groove 51 is provided at the end of the jet hole. The tapered groove 51 is used to control the jet angle. The outer periphery of the nozzle 5 is threadedly connected to the mounting hole 215.

[0033] During implementation, the fourth insertion part of drill rod 1 is sealed to the second insertion cavity of the slotter body 21, the third insertion part of drill rod 1 is threaded to the first insertion cavity of the slotter body 21, and the rear end of drill bit 3 is threaded to the first insertion part of the slotter body 21. The threaded connection ensures a tight and strong connection, preventing breakage during drilling. Multiple sealing rings are installed between the fourth insertion part and the second insertion cavity to further seal the connection, ensuring the high-pressure water pressure does not decrease during drilling and guaranteeing the slotting effect. During operation, when high-pressure water enters the drill rod 1 body through the front water-shrinking channel, the pressure and flow rate decrease, while the pressure and flow rate increase when flowing to the rear water-shrinking channel. This ensures that the pressure of the high-pressure water before slotting is not lost and reduces the water pressure on the drill rod 1, extending its service life. The first cavity 213 of the slotter body 21... The nozzle 5 has a diameter larger than the diameter of the water channel located at the rear end of the drill rod 1, ensuring sufficient high-pressure water is ejected during continuous kerf cutting, guaranteeing that the flow from the nozzle 5 will not be interrupted and ensuring the kerf cutting effect. The inner ring area of ​​the jet hole end of the nozzle 5 is smaller than the sum of the inner ring areas of the multiple flow-gathering holes. When high-pressure water passes through multiple flow-gathering holes and is ejected from the jet hole, the water pressure increases, thereby improving the cutting effect. The angle of the high-pressure water ejection from the jet hole can be controlled by the conical groove, further improving the cutting effect. The nozzle 5 is threadedly connected to the mounting hole 215 and can be disassembled and replaced. Different nozzles 5 and the appropriate number of nozzles 5 can be replaced according to the pressure and flow rate of the high-pressure water. The remaining mounting holes 215 can be plugged to achieve a better cutting effect. The first sealing section 211, the second sealing section 212, the first connecting section 11, and the second connecting section 12 are all compatible with each other. Therefore, this device can be used in series with multiple drill rods 1 or kerf cutting devices 2 according to different geological conditions, making it more flexible in use.

[0034] like Figure 3As shown, the slit cutting device 2 further includes a positioning valve assembly 22, which is used to form an end face seal for the first cavity 213. The positioning valve assembly 22 includes a guide post 221 and a compression spring 222. The guide post 221 has a T-shaped cross-section. The outer periphery of the rear end of the guide post 221 abuts against the inner wall of the large-diameter end of the first cavity 213, and the outer periphery of the rear end of the guide post 221 can coincide with the mounting hole 215. The outer periphery of the front end of the guide post 221 abuts against the inner wall of the small-diameter end of the first cavity 213. The compression spring 222 is sleeved around the guide post 221, and one end of the compression spring 222 is connected to the outer periphery of the guide post 221. The rear end of the guide post 221 abuts against the side wall of the first cavity 213; the positioning valve assembly 22 also includes a limiting member 223, which is detachably connected to the front end of the guide post 221. The limiting member 223 is located in the second cavity 214 and can abut against the end face of the first cavity 213; a sealing gasket is provided around the rear end of the guide post 221 in the circumferential direction, and multiple sealing rings are provided around the guide post 221 at the small diameter end of the first cavity 213. The sealing gasket and sealing rings are used to tightly seal the guide post 221 with the inner wall of the first cavity 213.

[0035] In practice, the compression spring 222 is first fitted onto the guide post 221, and then the assembly is installed into the first cavity 213 inside the main body 21 of the slotter. The front end of the guide post 221 is locked and fixed by the limiting member 223. The limiting member 223 and the guide post 221 can be connected by bolts or threads. When the pressure of the high-pressure water injected into the drill rod 1 is lower than a threshold, the spring is in the extended state. At this time, the rear end of the guide post 221 coincides with the end face of the mounting hole 215, and the nozzle will not spray water. When the pressure of the high-pressure water increases, the high-pressure water pushes the guide post 221 to squeeze the compression spring 222 to move backward, thereby causing the high-pressure water to be ejected through the nozzle 5. This allows control of the flow of high-pressure water. For particularly complex geological conditions, drilling can be carried out under low pressure and slotting can be done by spraying water under high pressure. There is no need to withdraw the drill rod 1 after drilling and then perform slotting. Drilling and slotting can be completed in one go.

[0036] The working principle of a coal seam hydraulic fracturing device 2 is as follows: During operation, the drill bit 3, fracturing device 2, drill rod 1, high-pressure water tail 4, high-pressure water pipe, high-pressure water pump, and drilling rig are connected sequentially from front to back. Adaptive nozzles 5 are installed according to geological requirements. The drilling rig drives the drill rod 1 to rotate and feed the material. High-pressure water is injected into the drill rod 1 through the high-pressure water pump. The high-pressure water enters the fracturing device body 21 and is ejected through the nozzles 5 to fracture the coal seam. Fracturing can be performed simultaneously with the drilling of the drill rod 1, improving work efficiency. The pressure of the high-pressure water controls the movement of the guide column 221, thereby controlling the opening and closing of the high-pressure water in the fracturing device body 21, thus achieving low-pressure drilling and high-pressure fracturing. This device features a modular design, facilitating disassembly, cleaning, and maintenance, and extending the service life of the equipment.

[0037] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A hydraulic fracturing device for coal seams, characterized in that: It includes a drill rod (1) and a slitting device (2) at its front end. A high-pressure water tail (4) is provided at the rear end of the drill rod (1). The stationary end of the high-pressure water tail (4) is fixedly connected to a high-pressure hose (6). The rotating end of the high-pressure water tail (4) is fixedly connected to the main shaft of the drilling rig. A drill bit (3) is provided at the front end of the slitting device (2). Multiple nozzles (5) are detachably provided along the circumferential direction on the outer wall of the slitting device (2).

2. The hydraulic fracturing device for coal seams according to claim 1, characterized in that: The slit cutting device (2) includes a slit cutter body (21), which includes a first sealing section (211) and a second sealing section (212). The first sealing section (211) and the second sealing section (212) are an integral structure. The first sealing section (211) is provided with a first insertion cavity and a second insertion cavity in sequence along the axial direction. The first insertion cavity is provided with an internal thread. The second sealing section (212) is provided with a first insertion part and a second insertion part in sequence along the axial direction. The first insertion part and the second insertion part are an integral structure. The first insertion part is provided with an external thread. The front end of the drill rod (1) is threadedly connected to the first insertion cavity, and the rear end of the drill bit (3) is threadedly connected to the first insertion part.

3. The hydraulic fracturing device for coal seams according to claim 2, characterized in that: The first sealing section (211) is provided with a first cavity (213), and the second sealing section (212) is provided with a second cavity (214). The first cavity (213) is a stepped hole, and the second cavity (214) is connected to the small diameter end of the first cavity (213). The inner diameter of the second cavity (214) is larger than the inner diameter of the small diameter end of the first cavity (213).

4. The hydraulic fracturing device for coal seams according to claim 3, characterized in that: The side wall of the first sealing section (211) is provided with multiple mounting holes (215) along the circumferential direction. Each mounting hole (215) is connected to the large diameter end of the first cavity (213), and a nozzle (5) is provided on each mounting hole (215).

5. A hydraulic coal seam cutting device according to claim 3, characterized in that: The slit cutting device (2) also includes a positioning valve assembly (22), which is used to form an end face seal of the first cavity (213). The positioning valve assembly (22) includes a guide post (221) and a compression spring (222). The guide post (221) has a T-shaped cross-section. The outer periphery of the rear end of the guide post (221) abuts against the inner wall of the large diameter end of the first cavity (213), and the outer periphery of the rear end of the guide post (221) can coincide with the mounting hole (215). The outer periphery of the front end of the guide post (221) abuts against the inner wall of the small diameter end of the first cavity (213). The compression spring (222) is sleeved on the outer periphery of the guide post (221), and one end of the compression spring (222) abuts against the rear end of the guide post (221) and the other end abuts against the side wall of the first cavity (213).

6. A hydraulic coal seam cutting device according to claim 5, characterized in that: The positioning valve assembly (22) also includes a limiting member (223), which is detachably connected to the front end of the guide post (221). The limiting member (223) is located in the second cavity (214) and can abut against the end face of the first cavity.

7. A hydraulic coal seam cutting device according to claim 6, characterized in that: A sealing gasket is provided around the rear end of the guide post (221) along the circumferential direction, and multiple sealing rings are provided around the guide post (221) located at the small diameter end of the first cavity (213).

8. A hydraulic fracturing device for coal seams according to claim 2, characterized in that: The drill rod (1) includes a middle section (13) and a first connecting section (11) and a second connecting section (12) respectively provided at both ends. The middle section (13), the first connecting section (11) and the second connecting section (12) are an integral structure. The first connecting section (11) is provided with a third insertion cavity and a fourth insertion cavity in sequence along the axial direction. The third insertion cavity is provided with an internal thread. The second connecting section (12) is provided with a third insertion part and a fourth insertion part in sequence along the axial direction. The third insertion part is provided with an external thread. The third insertion part is threadedly connected to the first insertion cavity. The fourth insertion cavity and the fourth insertion part are respectively provided with a shrinkage channel. The middle section (13) is provided with a cylindrical hole. The shrinkage channel and the cylindrical hole are coaxially arranged. The inner diameter of the cylindrical hole is larger than the inner diameter of the shrinkage channel.

9. A hydraulic fracturing device for coal seams according to claim 8, characterized in that: Multiple second sealing rings are respectively provided on the periphery of the fourth and second insertion parts.

10. A hydraulic coal seam cutting device according to claim 4, characterized in that: The nozzle (5) has a jet hole and multiple flow-gathering holes. The jet hole is located at the top of the nozzle (5), and the flow-gathering holes are located at the bottom of the nozzle (5). The inner area of ​​the jet hole is smaller than the sum of the inner areas of the multiple flow-gathering holes. A tapered groove (51) is provided at the end of the jet hole. The tapered groove (51) is used to control the jet angle. The outer periphery of the nozzle (5) is threadedly connected to the mounting hole (215).

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