Mechanical impact coal seam permeability enhancement device and method

Abstract

This invention discloses a mechanical impact coal seam permeability enhancement device and method, belonging to the field of coal reservoir gas extraction and permeability enhancement technology. It includes a telescopic cylinder, a remote control connector, and a push rod. The telescopic cylinder is connected to the remote control connector, which in turn is connected to the push rod. The telescopic cylinder includes an impact arm, which is connected to a high-pressure fluid source via the remote control connector. Under the drive of the high-pressure fluid, the impact arm is extended or retracted. A borehole is drilled in the coal seam, and the mechanical impact coal seam permeability enhancement device is inserted into the section to be permeated within the borehole via the push rod. High-pressure fluid is introduced into the mechanical impact coal seam permeability enhancement device, controlling the impact arm to extend and impact the borehole wall, generating cracks and / or shock waves in the coal seam surrounding the borehole wall. By applying high-frequency impact force to the borehole wall using the mechanical impact coal seam permeability enhancement device of this invention, micro-cracks and shock waves are formed in the coal seam surrounding the borehole, achieving the coal seam permeability enhancement effect. The steps are simple and convenient to implement.

Description

Technical Field

[0001] This invention belongs to the field of coal reservoir gas extraction and permeability enhancement technology, specifically relating to a mechanical impact coal seam permeability enhancement device and method. Background Technology

[0002] As a crucial component of my country's energy system, the safe and efficient mining of coal directly impacts the stability of energy supply and the safety of mine production. With the gradual depletion of shallow coal resources and the continuous increase in mining depth, the proportion of high-gas, low-permeability coal seams being mined is constantly rising. Gas disaster prevention and efficient utilization of gas resources have become core bottlenecks restricting the high-quality development of the coal industry. High-gas mines in my country are mostly located in low-permeability coal seams. These seams generally possess characteristics such as high gas content, high pressure, poor permeability, and complex structure. Gas is easily enriched and poses a high risk of outbursts, making gas drainage extremely difficult.

[0003] To address the challenge of gas extraction from low-permeability coal seams, the industry has explored various permeability enhancement technologies, such as hydraulic fracturing, hydraulic slotting, and ultrasonic fracturing. However, these technologies all have significant drawbacks. Hydraulic fracturing easily leads to increased coal moisture content, affecting subsequent gas desorption, and is prone to uncontrolled fracture guidance in complex coal seams. Hydraulic slotting also easily leads to increased coal moisture content, has poor adaptability to soft coal seams, and is prone to problems such as difficulty in slag removal, drill bit jamming, borehole collapse, borehole blockage, and blowout. Ultrasonic fracturing technology converts electrical energy into ultrasonic waves that act on the coal seam. High-power electrical equipment poses significant safety hazards in high-gas environments in underground coal mines. Due to limitations in the power of underground electrical equipment and borehole size, the permeability enhancement effect of ultrasound on the coal seam is limited, the permeability enhancement effect is difficult to guarantee, and the safety risks are significant.

[0004] In summary, given the current difficulties in gas extraction from high-gas, low-permeability coal seams and the shortcomings of existing permeability enhancement technologies, a mechanical impact coal seam permeability enhancement device and method with stable permeability enhancement effect is proposed. This has significant practical and engineering value for improving coal mine gas extraction efficiency, ensuring safe mine production, promoting the utilization of gas resources, and reducing environmental pollution. Summary of the Invention

[0005] This invention addresses the aforementioned problems and overcomes the shortcomings of existing technologies by providing a mechanical impact coal seam permeability enhancement device and method. By applying high-frequency impact force to the borehole wall through the mechanical impact coal seam permeability enhancement device, micro-cracks and shock waves are formed in the coal body surrounding the borehole, achieving a coal seam permeability enhancement effect. The steps are simple and convenient to implement, thus solving the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution.

[0007] A mechanical impact coal seam permeability enhancement device includes a telescopic cylinder, a remote control connector, and a push rod. The telescopic cylinder is connected to the remote control connector, and the remote control connector is connected to the push rod. The telescopic cylinder includes a telescopic impact arm. The telescopic cylinder is connected to a high-pressure fluid source through the remote control connector, and the impact arm is controlled to extend or retract under the drive of the high-pressure fluid.

[0008] In a preferred embodiment of the present invention, the telescopic cylinder includes a first flow guide port and a second flow guide port, and the remote control connector includes a first flow inlet, a second flow inlet, and a push rod adapter; the first flow guide port is connected to the first flow inlet, the second flow guide port is connected to the second flow inlet, and the push rod adapter is connected to the push rod.

[0009] As another preferred embodiment of the present invention, the mechanical impact coal seam permeability enhancement device includes multiple telescopic cylinders, the impact arms of the multiple telescopic cylinders having different extension directions; the multiple telescopic cylinders are fixed and connected to each other through guide valve plates.

[0010] As another preferred embodiment of the present invention, the telescopic cylinder further includes a third flow guide port and a fourth flow guide port, and the flow guide valve plate includes a first interface, a first connecting pipe, a second interface, a third interface, a second connecting pipe, a fourth interface, and a plug connector; the telescopic cylinder and the flow guide valve plate are connected by the plug interface and the plug connector, and the third flow guide port of the telescopic cylinder, the first interface and the first connecting pipe opened on the front side of the flow guide valve plate, the second interface and the first flow guide port opened on the back side of the flow guide valve plate are connected; the fourth flow guide port of the telescopic cylinder, the third interface and the second connecting pipe opened on the front side of the flow guide valve plate, the fourth interface and the second flow guide port opened on the back side of the flow guide valve plate are connected.

[0011] As another preferred embodiment of the present invention, a high-pressure guide pipe is provided inside the push rod. The high-pressure guide pipe is connected to the first inlet and the second inlet through an adapter. The high-pressure guide pipe injects high-pressure fluid into the first guide port and the second guide port of the telescopic cylinder through the adapter, the first inlet and the second inlet.

[0012] In addition, the present invention provides a mechanical impact coal seam permeability enhancement method, implemented using the aforementioned mechanical impact coal seam permeability enhancement device, the mechanical impact coal seam permeability enhancement method comprising the following steps: Step 1: Drill a hole in the coal seam and insert the mechanical impact coal seam permeability enhancement device into the permeability enhancement section of the hole through a pusher rod; Step 2: High-pressure fluid is introduced into the mechanical impact coal seam permeability enhancement device to control the impact arm to extend and impact the borehole wall, generating cracks and / or shock waves in the coal body around the borehole wall. Step 3: Move the mechanical impact coal seam permeability enhancement device to the next permeability enhancement section using the push rod, and repeat Step 2.

[0013] Furthermore, in step one, multiple adjacent boreholes are selected, and a mechanical impact coal seam permeability enhancement device is inserted into each borehole. Multiple adjacent boreholes are simultaneously subjected to impact force through the mechanical impact coal seam permeability enhancement device, and step two is executed simultaneously.

[0014] Furthermore, in step two, the impact energy generated by the mechanical impact coal seam permeability enhancement device is controlled to be greater than the energy threshold required for the formation of coal seam cracks.

[0015] Furthermore, in step two, the impact force exerted by the impact arm on the borehole wall is controlled to be less than the compressive strength of the coal.

[0016] Furthermore, in step two, the mechanical impact coal seam permeability enhancement device includes multiple telescopic cylinders, and the impact arms of the multiple telescopic cylinders simultaneously impact the borehole wall in multiple directions.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides a mechanical impact coal seam permeability enhancement device and method, which applies high-frequency impact force to the borehole wall to form micro-cracks and shock waves in the coal body around the borehole, thereby achieving the effect of coal seam permeability enhancement. The steps are simple and easy to implement; it effectively solves the problems mentioned in the background art. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the mechanical impact coal seam permeability enhancement device of the present invention. Figure 1 .

[0019] Figure 2 This is a schematic diagram of the mechanical impact coal seam permeability enhancement device of the present invention. Figure 2 .

[0020] Figure 3 This is a CC cross-sectional view of the mechanical impact coal seam permeability enhancement device of the present invention.

[0021] Figure 4 This is a DD cross-sectional view of the mechanical impact coal seam permeability enhancement device of the present invention.

[0022] Figure 5 This is a schematic diagram illustrating the mechanical impact coal seam permeability enhancement method using the mechanical impact coal seam permeability enhancement device of the present invention.

[0023] The markings in the diagram are as follows: 1000 is the borehole, 1001 is the borehole wall, 1002 is the crack, 1003 is the shock wave, 1 is the mechanical impact coal seam permeability enhancement device, 100 is the telescopic cylinder, 101 is the impact arm, 102 is the first guide port, 103 is the second guide port, 104 is the third guide port, 105 is the fourth guide port, and 106 is the plug-in interface; 2 is the remote control connector, 201 is the first inlet, 202 is the second inlet, and 203 is the push rod adapter; 3 is the push rod, 301 is the high-pressure guide pipe, and 302 is the adapter; 4 is the guide valve plate, 401 is the first interface, 402 is the first connecting pipe, 403 is the second interface, 404 is the third interface, 405 is the second connecting pipe, 406 is the fourth interface, and 407 is the plug-in interface. Detailed Implementation

[0024] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0025] Please see Figures 1 to 4 This invention provides a mechanical impact coal seam permeability enhancement device, comprising a telescopic cylinder 100, a remote control connector 2, and a push rod 3. The telescopic cylinder 100 is connected to the remote control connector 2, and the remote control connector 2 is connected to the push rod 3. The telescopic cylinder 100 includes a telescopic impact arm 101, which is connected to a high-pressure fluid source via the remote control connector 2. Under the drive of the high-pressure fluid, the impact arm 101 is extended or retracted. The telescopic cylinder 100 includes a first guide port 102 and a second guide port 103. The remote control connector 2... It includes a first inlet 201, a second inlet 202, and a push rod adapter 203; a first guide port 102 is connected to the first inlet 201, a second guide port 103 is connected to the second inlet 202, and a push rod adapter 203 is connected to the push rod 3; when high-pressure fluid enters the telescopic cylinder 100 through the first inlet 201 and the first guide port 102, the impact arm 101 extends under the action of the high fluid; when high-pressure fluid enters the telescopic cylinder 100 through the second inlet 202 and the second guide port 103, the impact arm 101 retracts under the action of the high fluid.

[0026] Specifically, the mechanical impact coal seam permeability enhancement device 1 includes multiple telescopic cylinders 100, and the impact arms 101 of the multiple telescopic cylinders 100 have different extension directions; the multiple telescopic cylinders 100 are fixed and connected to each other through a guide valve plate 4.

[0027] Specifically, the telescopic cylinder 100 further includes a third guide port 104 and a fourth guide port 105. The guide valve plate 4 includes a first interface 401, a first connecting pipe 402, a second interface 403, a third interface 404, a second connecting pipe 405, a fourth interface 406, and a connector 407. The telescopic cylinder 100 and the guide valve plate 4 are connected by the connector 106 and the connector 407 to achieve a high-pressure sealed connection. The third guide port 104 of the telescopic cylinder 100, the first interface 401 and the first connecting pipe 402 on the front of the guide valve plate 4, and the second interface 406 on the back of the guide valve plate 4 are all connected by the third guide port 104, the first interface 401 on the front of the guide valve plate 4, the first connecting pipe 402, and the fourth interface 406. The first inlet 201 and the second inlet 202 are connected; the fourth inlet 205 of the telescopic cylinder 100, the third interface 404 on the front of the guide valve plate 4, the second connecting pipe 405, the fourth interface 406 on the back of the guide valve plate 4, and the second inlet 203 are connected; thus, when the high-pressure fluid enters the multiple telescopic cylinders 100 through the first inlet 201, the impact arms 101 of the multiple telescopic cylinders 100 extend under the action of the high fluid, and when the high-pressure fluid enters the multiple telescopic cylinders 100 through the second inlet 202, the impact arms 101 of the multiple telescopic cylinders 100 retract under the action of the high fluid.

[0028] Specifically, a high-pressure guide pipe 301 is provided inside the push rod 3. The high-pressure guide pipe 301 is connected to the first inlet 201 and the second inlet 202 through the adapter 302. The high-pressure guide pipe 301 injects high-pressure fluid into the first guide port 102 and the second guide port 103 of the telescopic cylinder 100 through the adapter 302, the first inlet 201 and the second inlet 202. A high-pressure injection pump is provided outside the borehole 1000 as a high-pressure fluid source to provide high-pressure fluid. The high-pressure injection pump injects high-pressure fluid into the first guide port 102 and the second guide port 103 through the high-pressure guide pipe 301 in a time-sharing manner.

[0029] In addition, the present invention provides a mechanical impact coal seam permeability enhancement method, which is implemented using the aforementioned mechanical impact coal seam permeability enhancement device 1. The mechanical impact coal seam permeability enhancement method includes the following steps: Step 1: After drilling 1000 in the coal seam, the mechanical impact coal seam permeability enhancement device 1 is sent into the permeability enhancement section in the drilling 1000 through the push rod 3. Preferably, in step one, multiple adjacent boreholes 1000 are selected, and a mechanical impact coal seam permeability enhancement device 1 is sent into each borehole 1000 to the bottom of the borehole or the section to be permeable, while simultaneously performing step two. Preferably, multiple adjacent boreholes 1000 are simultaneously subjected to impact force F by a mechanical impact coal seam permeability enhancement device 1, thereby creating a superposition effect of impact force F in the coal body.

[0030] Step 2: High-pressure fluid is introduced into the mechanical impact coal seam permeability enhancement device 1, and the impact arm 101 is controlled to extend and impact the borehole wall 1001 of the borehole 1000, generating cracks 1002 and / or shock waves 1003 in the coal body around the borehole wall 1001. Preferably, in step two, the impact energy generated by the mechanical impact coal seam permeability enhancement device 1 is controlled to be greater than the energy threshold J required for the formation of coal body crack 1002; Preferably, in step two, the impact force of the impact arm 101 acting on the borehole wall 1001 is controlled to be less than the compressive strength of the coal body, thereby ensuring the integrity of the coal body and the continuity of action, and preventing borehole collapse. Preferably, in step two, the mechanical impact coal seam permeability enhancement device 1 includes multiple telescopic cylinders 100, and the impact arms 101 of the multiple telescopic cylinders 100 simultaneously impact the borehole wall 1001 in multiple directions. High-pressure fluid is remotely injected through a mechanical impact coal seam permeability enhancement device 1. The impact arm 101 of the device 1 is controlled to extend at high frequency out of the borehole wall 1001 of the borehole 1000, generating cracks 1002 and shock waves 1003 in the coal body on one side of the borehole wall 1001. This increases the number of cracks 1002 in the surrounding coal body, increases the permeability of the coal body, and accelerates the desorption of gas in the coal body under the energy of the shock wave 1003. (Mechanical impact can achieve the permeability enhancement effect by changing the internal structure and gas occurrence state of the gas-bearing coal body. Mechanical impact...) When impacted, coal particles undergo impact and rearrangement, disrupting the original structure of the coal and loosening the bonds between particles, thereby enhancing the connectivity of pores and fractures. Simultaneously, the impact energy disturbs the movement of gas molecules, destroys adsorption sites on the coal surface, reduces the coal's ability to adsorb gas, promotes the desorption of adsorbed gas into free gas, and accelerates gas diffusion and migration. The shock waves generated by high-frequency impacts can also increase the internal energy of the coal seam and the kinetic energy of gas molecules, causing the free gas to expand and further propel the gas towards the borehole, thus improving coal seam permeability and gas extraction efficiency. Step 3: Move the mechanical impact coal seam permeability enhancement device 1 towards the borehole opening using the push rod 3 to the next permeability enhancement section, and repeat steps 1 and 2 to achieve impact permeability enhancement in multiple borehole sections.

[0031] It is understood that, although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A mechanical impact coal seam permeability enhancement device, characterized in that, It includes a telescopic cylinder (100), a remote control connector (2), and a push rod (3). The telescopic cylinder (100) is connected to the remote control connector (2), and the remote control connector (2) is connected to the push rod (3). The telescopic cylinder (100) includes a telescopic impact arm (101). The telescopic cylinder (100) is connected to a high-pressure fluid source through the remote control connector (2) and controls the impact arm (101) to extend or retract under the drive of the high-pressure fluid.

2. The mechanical impact coal seam permeability enhancement device according to claim 1, characterized in that, The telescopic cylinder (100) includes a first guide port (102) and a second guide port (103). The remote control connector (2) includes a first inlet port (201), a second inlet port (202), and a push rod adapter (203). The first guide port (102) is connected to the first inlet port (201), the second guide port (103) is connected to the second inlet port (202), and the push rod adapter (203) is connected to the push rod (3).

3. The mechanical impact coal seam permeability enhancement device according to claim 2, characterized in that, The mechanical impact coal seam permeability enhancement device (1) includes multiple telescopic cylinders (100), and the impact arms (101) of the multiple telescopic cylinders (100) have different extension directions; the multiple telescopic cylinders (100) are fixed and connected to each other through a guide valve plate (4).

4. The mechanical impact coal seam permeability enhancement device according to claim 3, characterized in that, The telescopic cylinder (100) further includes a third guide port (104) and a fourth guide port (105). The guide valve plate (4) includes a first interface (401), a first connecting pipe (402), a second interface (403), a third interface (404), a second connecting pipe (405), a fourth interface (406), and a connector (407). The telescopic cylinder (100) and the guide valve plate (4) are connected via the connector (106) and the connector (407). The third guide port (104), the first interface (401) on the front of the guide valve plate (4), the first connecting pipe (402), the second interface (403) on the back of the guide valve plate (4), and the first guide port 102 are connected together; the fourth guide port (105) of the telescopic cylinder (100), the third interface (404) on the front of the guide valve plate (4), the second connecting pipe (405), the fourth interface (406) on the back of the guide valve plate (4), and the second guide port (103) are connected together.

5. The mechanical impact coal seam permeability enhancement device according to claim 2, characterized in that, The push rod (3) is provided with a high-pressure guide pipe (301). The high-pressure guide pipe (301) is connected to the first inlet (201) and the second inlet (202) through the adapter (302). The high-pressure guide pipe (301) injects high-pressure fluid into the first guide port (102) and the second guide port (103) of the telescopic cylinder (100) through the adapter (302), the first inlet (201) and the second inlet (202).

6. A mechanical impact method for enhancing the permeability of coal seams, characterized in that, The mechanical impact coal seam permeability enhancement device (1) according to any one of claims 1-5 is used, and the mechanical impact coal seam permeability enhancement method includes the following steps: Step 1: Drill a hole (1000) in the coal seam and send the mechanical impact coal seam permeability enhancement device (1) into the permeability enhancement section in the hole (1000) through the push rod (3); Step 2: High pressure fluid is introduced into the mechanical impact coal seam permeability enhancement device (1) to control the impact arm (101) to extend and impact the borehole wall (1001) of the borehole (1000), thereby generating cracks (1002) and / or shock waves (1003) in the coal body around the borehole wall (1001). Step 3: Move the mechanical impact coal seam permeability enhancement device (1) to the next permeability enhancement section by means of the push rod (3), and repeat steps 1 and 2.

7. The mechanical impact coal seam permeability enhancement method according to claim 6, characterized in that, In step one, multiple adjacent boreholes (1000) are selected, and a mechanical impact coal seam permeability enhancement device (1) is sent into each borehole (1000). Multiple adjacent boreholes (1000) are simultaneously subjected to impact force by the mechanical impact coal seam permeability enhancement device (1), and step two is executed simultaneously.

8. The mechanical impact coal seam permeability enhancement method according to claim 6 or 7, characterized in that, In step two, the impact energy generated by the mechanical impact coal seam permeability enhancement device (1) is controlled to be greater than the energy threshold required for the formation of coal seam cracks.

9. The mechanical impact coal seam permeability enhancement method according to claim 6 or 7, characterized in that, In step two, the impact force of the impact arm (101) acting on the borehole wall (1001) is controlled to be less than the compressive strength of the coal body.

10. The mechanical impact coal seam permeability enhancement method according to claim 6 or 7, characterized in that, In step two, the mechanical impact coal seam permeability enhancement device (1) includes multiple telescopic cylinders (100), and the impact arms (101) of the multiple telescopic cylinders (100) simultaneously impact the borehole wall (1001) in multiple directions.

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