Combined hole enlarging method and device

Abstract

The present invention relates to a combined hole enlarging method and device in the field of coal mine drilling technology. On the basis of ordinary drilling, a combined hole enlarging device is used to realize flexible combined hole enlarging in a manner of combining hydraulic hole enlarging and mechanical flexible hole enlarging. The combined hole enlarging device includes a drill rod, a hydraulic cutting head and a flexible hole enlarging drill bit. The flexible hole enlarging drill bit includes a hole enlarging seat and a swing chain or a swing cable. The swing chain or the swing cable are made of high-strength wear-resistant metal materials, and a high-pressure hose is inserted into the swing chain or the swing cable. A high-pressure water jet port is provided at one end of the high-pressure hose away from the hole enlarging seat. The present invention uses a combination of hydraulic cutting and flexible mechanical hole enlarging to quickly and efficiently enlarge the coal mine gas extraction borehole. The device has a simple structure, high reliability, good wear resistance and stability, and is convenient for drilling back, and is suitable for popularization and application.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mine drilling, and in particular, relates to a combined hole enlarging method and device. Background Art

[0002] Before coal mining, it is necessary to drill holes to extract gas. When drilling, it is necessary to drill from the rock layer to the coal seam. In order to save drilling costs and increase gas extraction efficiency, it is necessary to expand the borehole of the coal seam section while ensuring that the borehole diameter of the rock layer section remains unchanged, so as to expand the surface area of ​​the inner hole of the coal seam and improve the gas overflow efficiency. The existing gas extraction drilling and expanding hole device and expanding hole method have problems such as low working efficiency, difficulty in drilling back, and low reliability. Therefore, it is urgent to improve the existing drilling and expanding hole method and device. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a combined hole expansion method, comprising the following steps:

[0004] 1) Drilling location: measure and lay out according to coal seam conditions to locate the drilling position;

[0005] 2) Drilling: First, use an ordinary gas extraction drill to drill an ordinary borehole through the rock layer to the coal seam. When the ordinary borehole depth reaches the designed position, stop drilling and withdraw the ordinary drill bit;

[0006] 3) Hole expansion: Flexible joint hole expansion is carried out by combining hydraulic hole expansion and mechanical flexible hole expansion;

[0007] 31) Hydraulic hole expansion, using a hydraulic cutting head with high-pressure nozzles along the radial direction to carry out hydraulic hole expansion;

[0008] 32) Mechanical flexible hole reaming, a flexible hole reaming drill bit is connected to the rear end of the hydraulic cutting head, and mechanical flexible hole reaming is performed through the flexible hole reaming drill bit, the flexible hole reaming drill bit is driven by a drill rod with a reduction motor, and a radially arranged swing chain or swing cable is provided on the flexible hole reaming drill bit, and a high-pressure hose is passed through the swing chain or swing cable, and the high-pressure hose is connected to the high-pressure water in the hole reaming drill bit, and the end of the high-pressure hose away from the flexible hole reaming drill bit cooperates with the swing chain or swing cable through the high-pressure water jet port to synchronously perform hydraulic assisted cutting on the borehole.

[0009] Preferably, in step 32), the operating speed of the reduction motor is 500r / min, and the rotational inertia is used to stretch the chain or cable, so as to ensure the accuracy of the hole expansion size and improve the hole expansion efficiency.

[0010] Preferably, the working pressure of the high-pressure water is 30 MPa, so as to achieve a better water cutting effect.

[0011] As another aspect of the present invention, the present invention also provides a combined reaming device, including a drill rod, a hydraulic cutting head and a flexible reaming drill bit, one end of the drill rod is transmission-connected to a reduction motor, and the other end is fixedly connected to the flexible reaming drill bit, the hydraulic cutting head is connected to the end of the flexible reaming drill bit away from the drill rod, the drill rod, the flexible reaming drill bit and the hydraulic cutting head are provided with interconnected high-pressure water channels, a plurality of high-pressure nozzles are radially provided on the outer circumferential surface of the hydraulic cutting head, and a tunneling drill bit is also connected to the end of the hydraulic cutting head away from the flexible reaming drill bit, the flexible reaming drill bit includes a reaming seat and a swing chain or a swing cable, the swing chain or the swing cable are made of high-strength and wear-resistant metal material, and a high-pressure hose is passed through the swing chain or the swing cable, and a high-pressure water jet port is provided at the end of the high-pressure hose away from the reaming seat. After the device enters the coal seam, the drilling depth can be increased by the excavation drill bit, and the hydraulic cutting head and the flexible reaming drill bit cooperate to achieve rapid reaming while drilling deep, and after the reaming is completed, the high-pressure hose is depressurized to achieve rapid withdrawal of the drill, thereby effectively improving the efficiency of the reaming operation and the reliability of the reaming device. The outer surfaces of the reaming seat and the drill rod are provided with spiral guide grooves, which facilitate timely delivery of the broken coal particles during reaming out of the borehole to ensure the reaming efficiency.

[0012] Preferably, the swing chain adopts a high-strength round-link chain for mining, which has a high degree of freedom and is not prone to fatigue damage.

[0013] Preferably, the high-pressure hose is an armored metal hose, which is beneficial to ensuring the service life of the high-pressure hose.

[0014] Preferably, the high-strength and wear-resistant metal material is 27SiMn, which has high strength and good wear resistance, and is beneficial to improving the service life of the device.

[0015] Preferably, the swing chain or the swing cable is provided with a diamond composite sheet to improve the wear resistance of the swing chain or the swing cable, which is beneficial to prolonging the service life of the device.

[0016] Preferably, the reaming seat is provided with three circles of reaming components at intervals along the axial direction, and each circle of reaming components includes at least two swing chains or swing cables to ensure the stability of the operation of the flexible reaming drill bit, improve the reliability of the device, and ensure the reaming efficiency.

[0017] Preferably, the reaming radii of the three circles of reaming assemblies are 100 mm, 200 mm and 250 mm respectively. The closer the chain or cable is to the hydraulic cutting head, the smaller the reaming radius is, so that the device reams the hole step by step from front to back in the drilling direction of the drill bit, so that each circle of reaming assemblies is within a reasonable reaming radius, reducing the wear of the device, improving the reaming efficiency and ensuring the reliability of the device.

[0018] The present invention also includes other steps, devices or components that enable the combined hole expansion method and device to be used normally, which are all conventional technical means in the field. In addition, the steps, devices or components not limited in the present invention all adopt conventional technical means in the field.

[0019] The present invention firstly uses an ordinary gas extraction drilling rig to drill ordinary boreholes in rock layers and coal seams, and after the ordinary drill bit is withdrawn, a flexible reaming drill bit with a hydraulic cutting head is replaced to carry out reaming operations. The hydraulic cutting head at the front end of the borehole first performs hydraulic jetting to make the coal seam looser, and then the coal seam is mechanically beaten by a swing chain or a swing cable on the flexible reaming drill bit to accelerate the crushing of the coal seam. A high-pressure hose is inserted into the swing chain or the swing cable, and the expansion and contraction effect of the high-pressure water on the high-pressure hose can be utilized to increase the extension stiffness of the swing chain or the swing cable, which helps to improve the mechanical reaming efficiency. Combined with the high-pressure water jet port at the end of the high-pressure hose in the swing chain or the swing cable, the coal seam in the borehole is assisted in hydraulic cutting, which is beneficial to improving the reliability of the swing chain or the swing cable, and is beneficial to further improving the reaming efficiency.

[0020] The beneficial effect of the present invention is that the present invention quickly and efficiently expands the coal mine gas extraction borehole by combining hydraulic cutting and flexible mechanical expansion, the device has a simple structure, high reliability, good wear resistance and stability, convenient drill withdrawal, and is suitable for promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0022] Figure 1 It is a schematic diagram of the overall structure of the combined hole expanding device of the present invention.

[0023] Figure 2 It is a three-dimensional structural schematic diagram of the end of the swing chain in the present invention. DETAILED DESCRIPTION

[0024] The present invention is described clearly below in conjunction with the drawings and specific embodiments in the embodiments of the present invention. The description herein is only used to explain the present invention, but is not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work, any modifications, equivalent substitutions, improvements, etc., should be included in the protection scope of the present invention.

[0025] Example 1

[0026] The present invention provides a combined hole enlarging method, comprising the following steps:

[0027] 1) Drilling location: measure and lay out according to coal seam conditions to locate the drilling position;

[0028] 2) Drilling: First, use a common gas extraction drill to drill a common borehole through the rock layer to the coal seam. When the common borehole depth reaches the designed position, stop drilling and withdraw the common drill bit;

[0029] 3) Hole expansion: Flexible joint hole expansion is carried out by combining hydraulic hole expansion and mechanical flexible hole expansion;

[0030] 31) Hydraulic hole expansion, using a hydraulic cutting head with high-pressure nozzles along the radial direction to carry out hydraulic hole expansion;

[0031] 32) Mechanical flexible hole expansion, a flexible hole expansion drill bit is connected to the rear end of the hydraulic cutting head, and mechanical flexible hole expansion is performed through the flexible hole expansion drill bit, the flexible hole expansion drill bit is driven by a drill rod with a reduction motor, and a radially arranged swing chain or cable is provided on the flexible hole expansion drill bit, and a high-pressure hose is passed through the swing chain or cable, and the high-pressure hose is connected to the high-pressure water in the hole expansion drill bit, and the end of the high-pressure hose away from the flexible hole expansion drill bit cooperates with the swing chain or cable through the high-pressure water jet port to synchronously perform hydraulic assisted cutting on the borehole; the working speed of the reduction motor is 500r / min, and the rotational inertia is used to stretch the swing chain or cable, so as to ensure the accuracy of the hole expansion size and improve the hole expansion efficiency; the working pressure of the high-pressure water is 30MPa, so as to achieve a better hydraulic cutting effect.

[0032] Example 2

[0033] like Figures 1-2 As shown, the present invention also provides a combined reaming device, including a drill pipe 1, a hydraulic cutting head 2 and a flexible reaming drill bit 3, one end of the drill pipe 1 is transmission-connected to a reduction motor (not shown in the figure), and the other end is fixedly connected to the flexible reaming drill bit 3, the hydraulic cutting head 2 is connected to the end of the flexible reaming drill bit 3 away from the drill pipe 1, the drill pipe 1, the flexible reaming drill bit 3 and the hydraulic cutting head 2 are provided with interconnected high-pressure waterways 4, a plurality of high-pressure nozzles 5 are radially provided on the outer circumferential surface of the hydraulic cutting head 2, and a tunneling drill bit 6 is also connected to the end of the hydraulic cutting head 2 away from the flexible reaming drill bit 3, the flexible reaming drill bit 3 includes a reaming seat 3-1 and a swing chain 3-2, the swing chain 3-2 is made of high-strength and wear-resistant metal material, and a high-pressure hose 3-21 is passed through the swing chain 3-2, and a high-pressure water jet port is provided at the end of the high-pressure hose 3-21 away from the reaming seat 3-1. After the device enters the coal seam, the drilling depth can be increased through the excavation drill bit 6, and the hydraulic cutting head 2 and the flexible reaming drill bit 3 cooperate to achieve rapid reaming while drilling deeper, and after the reaming is completed, the high-pressure hose 3-21 is depressurized to achieve rapid drill withdrawal, thereby effectively improving the work efficiency of the reaming operation and the reliability of the reaming device.

[0034] The outer surfaces of the reaming seat 3-1 and the drill rod 1 are provided with a spiral guide groove 7, which is convenient for timely conveying the broken coal particles during reaming out of the drill hole to ensure the reaming efficiency. The swing chain 3-2 adopts a high-strength round link chain for mining, which has a high degree of freedom and is not prone to fatigue damage. The high-pressure hose 3-21 adopts an armored metal hose, which is beneficial to ensure the service life of the high-pressure hose 3-21. The high-strength wear-resistant metal material is selected from 27SiMn material, which has high strength and good wear resistance; the swing chain 3-2 is provided with a diamond composite sheet 8, which can improve the wear resistance of the swing chain 3-2 and help to extend the service life of the device. The reaming seat 3-1 is provided with three circles of reaming assemblies at intervals along the axial direction, and each circle of reaming assemblies includes at least two swing chains 3-2 to ensure the stability of the operation of the flexible reaming drill bit 3, improve the reliability of the device, and ensure the reaming efficiency. The reaming radii of the three circles of reaming assemblies are 100mm, 200mm and 250mm respectively. The closer the swing chain 3-2 is to the hydraulic cutting head 2, the smaller the reaming radius is, so that the device reams the hole step by step from front to back in the drilling direction of the drill bit, so that each circle of reaming assemblies is within a reasonable reaming radius, reducing the wear of the device, improving the reaming efficiency and ensuring the reliability of the device.

[0035] The present invention firstly uses an ordinary gas extraction drilling rig to drill ordinary boreholes in rock layers and coal seams. After the ordinary drill bit is withdrawn, a flexible reaming drill bit 3 with a hydraulic cutting head 2 is replaced to carry out reaming operations. The hydraulic cutting head 2 at the front end of the borehole first performs hydraulic jetting to make the coal seam looser. Then, the coal seam is mechanically beaten by the swing chain 3-2 on the flexible reaming drill bit 3 to accelerate the crushing of the coal seam. By inserting a high-pressure hose 3-21 in the swing chain 3-2 and utilizing the expansion and contraction effect of high-pressure water on the high-pressure hose 3-21, the extension stiffness of the swing chain 3-2 can be increased, which helps to improve the mechanical reaming efficiency. Combined with the high-pressure water jet port at the end of the high-pressure hose 3-21 in the swing chain 3-2, the coal seam in the borehole is assisted in hydraulic cutting, which is beneficial to improving the reliability of the swing chain 3-2 and further improving the reaming efficiency.

[0036] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A combined hole enlarging method, characterized in that: The steps include: 1) Drilling location: measure and lay out according to coal seam conditions to locate the drilling position; 2) Drilling: First, use a common gas extraction drill to drill a common borehole through the rock layer to the coal seam. When the common borehole depth reaches the designed position, stop drilling and withdraw the common drill bit; 3) Hole expansion: Flexible joint hole expansion is carried out by combining hydraulic hole expansion and mechanical flexible hole expansion; 31) Hydraulic hole expansion, using a hydraulic cutting head with high-pressure nozzles along the radial direction for hydraulic hole expansion; 32) Mechanical flexible hole reaming, a flexible hole reaming drill bit is connected to the rear end of the hydraulic cutting head, and mechanical flexible hole reaming is performed through the flexible hole reaming drill bit, the flexible hole reaming drill bit is driven by a drill rod with a reduction motor, and a radially arranged swing chain or swing cable is provided on the flexible hole reaming drill bit, and a high-pressure hose is passed through the swing chain or swing cable, and the high-pressure hose is connected to the high-pressure water in the hole reaming drill bit, and the end of the high-pressure hose away from the flexible hole reaming drill bit cooperates with the swing chain or swing cable through the high-pressure water jet port to perform hydraulic assisted cutting on the borehole synchronously.

2. The combined hole enlarging method according to claim 1, characterized in that: In step 32), the operating speed of the reduction motor is 500r / min.

3. The combined hole enlarging method according to claim 1, characterized in that: In step 32), the working pressure of the high-pressure water is 30 MPa.

4. A combined hole enlarging device based on the combined hole enlarging method according to claim 1, characterized in that: It includes a drill rod, a hydraulic cutting head and a flexible reaming drill bit, one end of the drill rod is transmission-connected to the reduction motor, and the other end is fixedly connected to the flexible reaming drill bit, the hydraulic cutting head is connected to the end of the flexible reaming drill bit away from the drill rod, the drill rod, the flexible reaming drill bit and the hydraulic cutting head are provided with interconnected high-pressure water channels, a plurality of high-pressure nozzles are radially provided on the outer circumferential surface of the hydraulic cutting head, and an end of the hydraulic cutting head away from the flexible reaming drill bit is also connected to a tunneling drill bit, the flexible reaming drill bit includes a reaming seat and a swing chain or a swing cable, the swing chain or the swing cable are made of high-strength and wear-resistant metal material, and a high-pressure hose is passed through the swing chain or the swing cable, a diamond composite sheet is provided on the swing chain or the swing cable, a high-pressure water jet port is provided at the end of the high-pressure hose away from the reaming seat, and the high-pressure hose adopts an armored metal hose.

5. The combined hole expanding device according to claim 4 is characterized in that: The swing chain adopts a high-strength round-link chain for mining.

6. The combined hole expanding device according to claim 4, characterized in that: The high-strength and wear-resistant metal material is 27SiMn.

7. The combined hole expanding device according to claim 4, characterized in that: The reaming seat is provided with three circles of reaming components at intervals along the axial direction, and each circle of reaming components includes at least two swing chains or swing cables.

8. The combined hole expanding device according to claim 7, characterized in that: The expansion radii of the three-circle expansion assembly are 100 mm, 200 mm and 250 mm respectively. The closer the swing chain or the swing cable is to the hydraulic cutting head, the smaller the expansion radius.

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