A system and method for enhanced coal recovery using mobile resonant devices

Abstract

The present application relates to coal bed gas exploration and development technical field, specifically disclose a kind of system and method for improving coal seam recovery using mobile resonance device, comprising: coal seam group, roof roadway, straight well, mobile resonance device, ground monitoring room and gas drainage system;Roof roadway is located in coal seam group roof;Two straight wells are located in coal seam group two sides and end is connected to coal seam group floor;Mobile resonance device is located in roof roadway;Ground monitoring room and gas drainage system are located on the ground;Two straight wells are connected with gas drainage system respectively.By the joint use of mobile resonance device and gas drainage system, it is helpful to solve the problem of low-permeability coalbed methane exploration and development that is easy to expand when meeting water, and promote the development of resonance stimulation technology in the field of coalbed methane.Provide a mobile resonance device including drill body, resonance probe and excitation bin, which has the functions of drilling, embedding probe, exciting resonance and migration, which is helpful to downhole resonance excitation.

Description

Technical Field

[0001] This invention relates to the field of coalbed methane exploration and development technology, and in particular to a system and method for improving coal seam recovery rate using a mobile resonance device. Background Technology

[0002] Coalbed methane (CBM) resources are abundant and have enormous development potential. Suitable CBM exploration and development systems and methods can help improve CBM utilization and reduce coal mine gas accidents. Currently, coal seams for CBM exploration and development are mainly divided into two categories based on their thickness and number of layers: one category consists of coal seams with few layers but large individual layer thickness, and the other category consists of coal seams with many layers but thin individual layer thickness. The main exploration challenges lie in the first category of coal seams. These seams are soft and, in some areas, easily expand when exposed to water. Appropriate technologies need to be selected for these seams to achieve both increased production and improved mine safety.

[0003] Surface coalbed methane wells include vertical wells, horizontal wells, directional feather horizontal wells, multi-branch horizontal wells, and U-shaped wells. Coalbed methane production enhancement methods include hydraulic fracturing, N2, CO2, or flue gas injection, thermal injection, nitrogen foam fracturing, and resonance methods. Hydraulic fracturing is the most mature production enhancement method; however, it is not suitable for extracting methane gas from low-permeability coal seams that easily expand when exposed to water. Resonance methods effectively solve this problem; when the excitation frequency reaches the resonance frequency of the coal seam, the fractures in the coal and rock increase. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a system and method for improving coal seam recovery rate by using a mobile resonance device, so as to solve the problems of coal seam groups with few coal seams and large single-layer thickness, soft coal quality, easy expansion when exposed to water in some areas and generation of gas, which endangers safety.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] On one hand, the present invention provides a system for improving coal seam recovery rate using a mobile resonance device, comprising: a coal seam group, a roof roadway, a vertical shaft, a mobile resonance device, a surface monitoring room, and a gas drainage system; the roof roadway is located on the roof of the coal seam group; two vertical shafts are located on both sides of the coal seam group and their ends are connected to the bottom of the coal seam group; the mobile resonance device is located in the roof roadway; the surface monitoring room and the gas drainage system are both located on the surface; the two vertical shafts are respectively connected to the gas drainage system.

[0007] Furthermore, the mobile resonance device includes a housing, a telescopic handle, a carrying handle, and wheels; each side of the top of the housing has a telescopic handle, the top of the housing has a carrying handle, and the bottom of the housing has four wheels; the housing is connected to a drill switch, which is connected to a motor drive device via wires in a wiring groove; the motor drive device is connected to a drive piston; below the drive piston is a vibration acceleration sensor and its housing, the lower part of which is connected to a rotary drill bit; the drill's motor drive device and housing are each equipped with several ventilation openings; multiple resonance probes are arranged vertically in the probe placement chamber, and the resonance probes are connected to a resonance trigger switch in the excitation chamber via corresponding lines; the control capacitor of the resonance trigger switch is connected to the resonance probe, the capacitor is connected to a high-voltage power supply, and the lines are also connected to an oscilloscope; each resonance probe is separated by a partition switch; the resonance probe includes a carbon rod wound with metal wire, an explosion chamber, a negative probe connected to the top and bottom of the carbon rod, and a positive probe.

[0008] Furthermore, each end of the gas extraction system is equipped with an explosion-proof mesh; after passing through the explosion-proof meshes at both ends, the gas enters the water-sealed tempering device, and is then extracted by the extraction pumps on both sides. The gas is discharged into the atmosphere or stored in the gas storage tank through the exhaust ports on both sides of the gas storage tank. The water-sealed tempering device and the upper part of the gas storage tank are respectively equipped with gas concentration gauges, and valves are provided at both ends of the extraction pump, the exhaust port, and the inlet of the gas storage tank.

[0009] Furthermore, the diameter of the rotary drill bit is 0-5 mm larger than the diameter of the resonant probe.

[0010] Furthermore, the horizontal distance between the two vertical wells is 200m-1000m.

[0011] Furthermore, the height of the roof tunnel is greater than 2m.

[0012] Furthermore, the distance between the bottom surface of the roof roadway and the coal seam group is -5cm to 5cm.

[0013] On the other hand, a method for improving coal seam recovery using a mobile resonance device, based on any one of the above-mentioned systems for improving coal seam recovery using a mobile resonance device, includes the following steps:

[0014] Step 1: Excavate the roof tunnel;

[0015] Step 2: Drill a vertical shaft to the bottom of the coal seam;

[0016] Step 3: Operate the mobile resonance device while monitoring the resonance frequency in the ground monitoring room;

[0017] Step 4: Run the gas extraction system;

[0018] Step 5: Gas safety inspection in the roof tunnel;

[0019] Step 6: Organize the mobile resonant device;

[0020] Step 7: Excavate the coal seam from top to bottom.

[0021] Furthermore, it also includes the operation steps of the mobile resonance device, which include the following steps:

[0022] Step a: Drilling;

[0023] Step b: Install the resonance probe;

[0024] Step c: Move the mobile resonant device;

[0025] Step d: Determine whether the burial work is complete;

[0026] Step e: Evacuation of personnel;

[0027] Step f: Remotely induce resonance and monitor the ground resonance frequency in real time.

[0028] Furthermore, the methane concentration range of the gas concentration meter is 0.00-6.00%.

[0029] The beneficial effects of this invention are:

[0030] 1. This invention provides a system for improving coal seam recovery by using a mobile resonance device. The combined use of the mobile resonance device and the gas drainage system helps to solve the problem of exploration and development of low-permeability coalbed methane that is prone to expansion when exposed to water, and promotes the development of resonance enhancement technology in the field of coalbed methane.

[0031] 2. This invention provides a mobile resonance device that includes a drill body, a resonance probe, and an excitation chamber. It also has the functions of drilling, probe placement, resonance excitation, and transportation, which helps to carry out downhole resonance excitation more flexibly. Attached Figure Description

[0032] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0033] Figure 1 A schematic diagram illustrating the use of resonance to enhance coalbed methane recovery in the field;

[0034] Figure 2 Front view of the mobile resonant device;

[0035] Figure 3 This is a top view of the exterior of the mobile resonant device.

[0036] Figure 4Top view of the interior of the mobile resonant device;

[0037] Figure 5 This is a schematic diagram of the structure of the resonance probe;

[0038] Figure 6 This is a schematic diagram of the gas extraction system.

[0039] Figure 7 A flowchart for utilizing resonance to enhance coalbed methane recovery;

[0040] Figure 8 This is a flowchart illustrating the operation steps of a mobile resonant device.

[0041] Figure reference numerals: 1. Coal seam group; 2. Roof roadway; 3. Vertical shaft; 4. Mobile resonance device; 5. Surface monitoring room; 6. Gas drainage system; 401. Housing; 402. Telescopic handle; 403. Handle; 404. Wheel; 405. Drill body switch; 406. Cable tray; 407. Wire; 408. Motor transmission device; 409. Drive piston; 410. Vibration acceleration sensor; 411. Housing; 412. Rotary drill bit; 413. Ventilation port; 414. Resonance probe; 415. 416. Probe placement room; 417. Wiring; 418. Excitation chamber; 419. Resonance trigger switch; 420. Capacitor; 421. High voltage power supply; 422. Oscilloscope; 423. Partition switch; 424. Winding metal wire; 425. Carbon rod; 426. Explosion chamber; 427. Negative probe; 428. Positive probe; 601. Explosion-proof mesh; 602. Water-sealed flashback device; 603. Drainage pump; 604. Exhaust port; 605. Gas storage tank; 606. Gas concentration gauge; 607. Valve. Detailed Implementation

[0042] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0043] The following detailed description is exemplary and intended to provide further detailed explanation of the invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this invention is for describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention.

[0044] Example 1

[0045] like Figure 1As shown, a system for improving coal seam recovery using a mobile resonance device includes: a coal seam group 1, a roof roadway 2, two vertical shafts 3, a mobile resonance device 4, a surface monitoring room 5, and a gas drainage system 6; the roof roadway 2 is located on the roof of the coal seam group 1; two vertical shafts 3 are located on both sides of the coal seam group 1 and their ends are connected to the floor of the coal seam group 1; the mobile resonance device 4 is located in the roof roadway 2; the surface monitoring room 5 and the gas drainage system 6 are both located on the surface; the two vertical shafts 3 are connected to the gas drainage system 6.

[0046] like Figures 2-5 As shown, the mobile resonance device 4 includes a housing 401, a telescopic handle 402, a carrying handle 403, and wheels 404. A telescopic handle 402 is provided on each side of the top of the housing 401, and a carrying handle 403 is provided at the center of the top of the housing 401. Four wheels 404 are provided at the bottom of the housing 401. A drill switch 405 is connected to the outside of the housing 401. The drill switch 405 is connected to a motor drive device 408 via a wire 407 in a wiring groove 406. The motor drive device 408 is connected to a drive piston 409. Below the drive piston 409 is a vibration acceleration sensor 410 and its housing 411. A rotary drill bit 412 is connected to the lower part of the housing 411. Several ventilation openings 413 are respectively installed on the drill motor drive device 408 and the housing 411. Multiple resonance probes 414 are arranged vertically in the probe placement chamber 415. The resonance probes 414 are connected to the resonance trigger switch 418 in the excitation chamber 417 through corresponding lines 416. The control capacitor 419 of the resonance trigger switch 418 is connected to the resonance probe 414. The capacitor 419 is connected to the high voltage power supply 420. At the same time, the line 416 is also connected to the oscilloscope 421. Each resonance probe 414 is separated by a partition switch 422. The resonance probe 414 includes a carbon rod 424 with a metal wire 423 wound around it, an explosion chamber 425, a negative probe 426 connected to the top and bottom of the carbon rod, and a positive probe 427.

[0047] like Figure 6 As shown, the gas extraction system 6 has an explosion-proof net 601 at each end; after passing through the explosion-proof nets 601 at both ends, the gas enters the water-sealed flashback device 602, and then is extracted by the extraction pumps 603 on both sides, and discharged into the atmosphere or stored in the gas storage tank 605 through the exhaust ports 604 on both sides of the gas storage tank 605. The water-sealed flashback device 602 and the upper part of the gas storage tank 605 are respectively equipped with gas concentration gauges 606, and valves 607 are provided at both ends of the extraction pump 603, the exhaust port 604, and the inlet of the gas storage tank 605.

[0048] The housing 401 and wheels 404 of the mobile resonance device 4 are made of a hard material that is non-conductive, waterproof, heat-dissipating, and wear-resistant; the telescopic handle 402 is made of a hard inner tube that is non-conductive and wrapped with a wear-resistant plastic or rubber material; the handle 403 is made of a non-conductive, heat-dissipating, and wear-resistant plastic or rubber material; the diameter of the rotary drill bit 412 is 0-5mm larger than the diameter of the resonance probe 414; the partition switch 422 can control the extension and retraction of the partition via a button.

[0049] The diameter of the metal wire 423 is 0.1mm-0.4mm, with 0.2mm recommended; the length is between 3cm-10cm, with 6cm recommended; the metal wire 423 is made of materials with high resistance such as copper or aluminum wire; the carbon rod 424 has a diameter of 1mm-2mm and a length consistent with that of the metal wire 423.

[0050] Example 2

[0051] like Figure 7 As shown, a method for improving coal seam recovery using a mobile resonance device includes the following steps:

[0052] Step 1: Excavate the roof tunnel 2.

[0053] Roof roadway 2 was excavated on the roof of coal seam group 1. The height of roof roadway 2 is greater than 2m. The distance between the bottom surface of roof roadway 2 and coal seam group 1 is within the range of -5cm to 5cm to ensure that the coal seam resonance achieves the expected effect. The excavation process was carried out in accordance with the "Coal Mine Safety Regulations".

[0054] Step 2: Drill a vertical shaft 3 to the bottom plate of coal seam group 1.

[0055] Two vertical shafts 3 are drilled in the working face, with a horizontal distance of 200m-1000m between the two vertical shafts 3, both reaching the bottom of coal seam group 1;

[0056] Step 3: Operate the mobile resonance device 4, while monitoring the resonance frequency in the ground monitoring room 5.

[0057] The mobile resonance device 4 is moved from near one vertical shaft 3 to near another, with the resonance excitation point spacing ranging from 50m to 200m, consistent with the set excitation energy. The ground monitoring room 5 is mainly equipped with a computer and a remote control device to control the resonance trigger switch 418 in the excitation chamber 417. The computer receives signals from the oscilloscope 421 and vibration acceleration sensor 410 in the mobile resonance device 4 in the roof tunnel 2 and performs spectrum analysis. After resonance ends, the resonance trigger switch 418 in the excitation chamber 417 is remotely turned off through the ground monitoring room 5.

[0058] Step 4: Run the gas extraction system 6.

[0059] After resonance, the gas extraction system 6 is activated. The gas passes through the explosion-proof mesh 601 and enters the water-sealed tempering device 602. Then, the gas is extracted by the extraction pump 603 and discharged into the atmosphere through the exhaust port 604 or stored in the gas storage tank 605. Gas concentration gauges 606 are installed on the upper part of the water-sealed tempering device 602 and the gas storage tank 605. Valves 607 are installed at both ends of the extraction pump 603, the exhaust port 604, and the inlet of the gas storage tank 605.

[0060] The 603 air pump can provide air extraction / injection power in the range of 0-20 kPa, with an average no-load flow rate of 0.4 L / min and an adjustment accuracy of 0.1 kPa.

[0061] The methane concentration range of gas concentration meter 606 is 0.00-6.00%.

[0062] Step 5: Gas safety inspection of roof tunnel 2.

[0063] According to the "Coal Mine Safety Regulations", the concentration of hazardous gases in the roof roadway 2 was checked, namely, the methane concentration did not exceed 1.0% and the carbon dioxide concentration did not exceed 1.5%, and the air composition met the ventilation requirements.

[0064] Step 6: Organize the mobile resonance device 4.

[0065] After the gas safety inspection of the roof roadway 2 is completed, personnel enter the roof roadway 2 to arrange the mobile resonance device 4, and retrieve the buried resonance probe 414 and place it in the probe installation room 415.

[0066] Step 7: Excavate the coal seam from top to bottom.

[0067] After the gas safety inspection of Roof Roadway 2, personnel enter Roof Roadway 2 to excavate the coal seam. First, the first layer of coal at the bottom of Roof Roadway 2 is excavated horizontally, and then the resonance operation is repeated for the next layer of coal. The mobile resonance device is operated in this way multiple times to carry out coal seam mining from top to bottom.

[0068] The motor drive device 408 has a speed range of 3 r / min to 600 r / min; the high-voltage power supply 420 has a voltage of 220V; the explosion chamber 425 contains argon gas at a pressure of 100 kPa.

[0069] Example 3

[0070] like Figure 8 The diagram shows the operating steps of the mobile resonant device, including the following steps:

[0071] Step a: Drilling;

[0072] The left side of the mobile resonance device 4 is the drill body. When the drill body switch 405 connected to the box 401 is turned on, the motor transmission device 408 is started, which drives the drive piston 409 and the rotating drill bit 412 to work, drilling downwards into a hole that is basically the same height as the resonance probe 414, so as to bury the resonance probe 414.

[0073] Step b: Embed the resonance probe 414;

[0074] After the partition switch 422 is turned on, the resonance probe 414 falls down and is embedded in the hole drilled in the previous step.

[0075] Step c: Move the mobile resonant device 4;

[0076] After completing one drilling and embedding of the resonance probe 414, the mobile resonance device 4 can be moved to the embedding point of the next resonance probe 414 via the telescopic handle 402 and the handle 403.

[0077] Step d: Determine whether the burial work is complete;

[0078] From one vertical well 3 to another vertical well 3, at fixed intervals ranging from 50m to 200m, a resonant probe 414 is buried; if not completed, repeat steps a to c; if completed, proceed to the next step.

[0079] Step e: Evacuation of personnel;

[0080] After completing the installation of the resonance probe 414, the drill body switch 405 was turned off, personnel were evacuated, and preparations were made for remote resonance activation.

[0081] Step f: Remotely induce resonance and monitor the ground resonance frequency in real time;

[0082] The resonance trigger switch 418 in the excitation chamber 417 is remotely controlled from the ground monitoring room 5. The high-voltage power supply 420 is connected to the capacitor 419. The generated current is connected to the negative probe 426 and the positive probe 427 of the resonance probe 414 through the line 416. The current passes through the carbon rod 424 wound with metal wire 423 and explodes in the explosion chamber 425 to generate resonance waves, causing the coal seam to resonate. At the same time, the vibration wave is fed back to the oscilloscope 421 for real-time monitoring and analysis.

[0083] 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 it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A system for improving coal seam recovery rate using a mobile resonance device, characterized in that, include: The coal seam group (1), roof roadway (2), vertical shaft (3), mobile resonance device (4), ground monitoring room (5), and gas drainage system (6) are located on the roof of the coal seam group (1). The two vertical shafts (3) are located on both sides of the coal seam group (1) and their ends are connected to the bottom of the coal seam group (1). The mobile resonance device (4) is located in the roof roadway (2). The ground monitoring room (5) and the gas drainage system (6) are both located on the ground. The two vertical shafts (3) are connected to the gas drainage system (6). The mobile resonance device (4) includes a housing (401), a telescopic handle (402), a handle (403), and wheels (404); each side of the top of the housing (401) is provided with a telescopic handle (402), the top of the housing (401) is provided with a handle (403), and the bottom of the housing (401) is provided with four wheels (404); the housing (401) is externally connected to a drill body switch (405), and the drill body switch (405) is connected to a motor transmission device (408) through a wire (407) in a wire slot (406); the motor transmission device (408) is connected to a drive piston (409); below the drive piston (409) is a vibration acceleration sensor (410) and a housing (411) of the vibration acceleration sensor (410), and the lower part of the housing (411) is connected to a rotary drill bit (412), and the drill body's electric... The transmission device (408) and the housing (411) are respectively equipped with several ventilation openings (413); multiple resonance probes (414) are arranged vertically in the probe placement room (415). The resonance probes (414) are connected to the resonance trigger switch (418) in the excitation chamber (417) through the corresponding line (416). The control capacitor (419) of the resonance trigger switch (418) is connected to the resonance probe (414). The capacitor (419) is connected to the high voltage power supply (420). At the same time, the line (416) is also connected to the oscilloscope (421). Each resonance probe (414) is separated by a partition switch (422). The resonance probe (414) includes a carbon rod (424) with a metal wire (423) wound around it, an explosion chamber (425), a negative probe (426) connected to the top and bottom of the carbon rod, and a positive probe (427).

2. The system for improving coal seam recovery using a mobile resonance device according to claim 1, characterized in that, The gas extraction system (6) is equipped with an explosion-proof net (601) at each end. After passing through the explosion-proof net (601) at both ends, the gas enters the water-sealed flashback device (602), and is then extracted by the extraction pumps (603) on both sides. The gas is discharged into the atmosphere or stored in the gas storage tank (605) through the exhaust ports (604) on both sides of the gas storage tank (605). The water-sealed flashback device (602) and the gas storage tank (605) are respectively equipped with gas concentration gauges (606). Valves (607) are provided at both ends of the extraction pump (603), the exhaust port (604), and the inlet of the gas storage tank (605).

3. A system for improving coal seam recovery using a mobile resonance device according to claim 1, characterized in that, The diameter of the rotary drill bit (412) is 0-5 mm larger than that of the resonant probe (414).

4. A system for improving coal seam recovery using a mobile resonance device according to claim 1, characterized in that, The horizontal distance between the two vertical wells (3) is 200m-1000m.

5. A system for improving coal seam recovery using a mobile resonance device according to claim 1, characterized in that, The height of the roof tunnel (2) is greater than 2m.

6. A system for improving coal seam recovery using a mobile resonance device according to claim 1, characterized in that, The distance between the bottom surface of the roof roadway (2) and the coal seam group (1) is -5cm-5cm.

7. A method for improving coal seam recovery rate using a mobile resonance device, characterized in that, A system for improving coal seam recovery using a mobile resonance device according to any one of claims 1-6, comprising the following steps: Step 1: Excavate the roof tunnel (2); Step 2: Drill a vertical well (3) to the bottom of the coal seam group (1); Step 3: Operate the mobile resonant device (4) while monitoring the resonant frequency in the ground monitoring room (5); Step 4: Run the gas extraction system (6); Step 5: Gas safety inspection of roof tunnel (2); Step 6: Organize the mobile resonant device (4); Step 7: Excavate the coal seam from top to bottom.

8. A method for improving coal seam recovery using a mobile resonance device according to claim 7, characterized in that, It also includes the operation steps of the mobile resonance device, which include the following steps: Step a: Drilling; Step b: Embed the resonance probe (414); Step c: Move the mobile resonant device (4); Step d: Determine whether the burial work is complete; Step e: Evacuation of personnel; Step f: Remotely induce resonance and monitor the ground resonance frequency in real time.

9. A method for improving coal seam recovery using a mobile resonance device according to claim 7, characterized in that, The methane concentration range of the gas concentration meter (606) is 0.00-6.00%.

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