CN113236346B - Anti-collapse reinforced gas extraction device and use method - Google Patents
Anti-collapse reinforced gas extraction device and use method Download PDFInfo
- Publication number
- CN113236346B CN113236346B CN202110717624.5A CN202110717624A CN113236346B CN 113236346 B CN113236346 B CN 113236346B CN 202110717624 A CN202110717624 A CN 202110717624A CN 113236346 B CN113236346 B CN 113236346B
- Authority
- CN
- China
- Prior art keywords
- hole
- slurry
- grouting
- battery
- pipe
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000605 extraction Methods 0.000 title claims abstract description 37
- 238000000034 method Methods 0.000 title claims abstract description 8
- 238000007789 sealing Methods 0.000 claims abstract description 67
- 239000002002 slurry Substances 0.000 claims abstract description 53
- 239000003245 coal Substances 0.000 claims abstract description 20
- 238000003756 stirring Methods 0.000 claims abstract description 15
- 239000012466 permeate Substances 0.000 claims abstract description 4
- 230000000903 blocking effect Effects 0.000 claims description 10
- 239000011440 grout Substances 0.000 claims description 10
- 238000005553 drilling Methods 0.000 claims description 8
- 230000002265 prevention Effects 0.000 claims description 5
- 238000002347 injection Methods 0.000 claims description 4
- 239000007924 injection Substances 0.000 claims description 4
- 238000004891 communication Methods 0.000 claims description 3
- 238000002360 preparation method Methods 0.000 claims description 3
- 230000002708 enhancing effect Effects 0.000 claims 1
- 238000011084 recovery Methods 0.000 abstract description 2
- 238000005728 strengthening Methods 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 4
- 230000000149 penetrating effect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21F—SAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINING IN OR OF MINES OR TUNNELS
- E21F7/00—Methods or devices for drawing- off gases with or without subsequent use of the gas for any purpose
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B12/00—Accessories for drilling tools
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B33/00—Sealing or packing boreholes or wells
- E21B33/10—Sealing or packing boreholes or wells in the borehole
- E21B33/13—Methods or devices for cementing, for plugging holes, crevices or the like
Landscapes
- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- Mechanical Engineering (AREA)
- Processing Of Solid Wastes (AREA)
- Drilling And Exploitation, And Mining Machines And Methods (AREA)
Abstract
The invention discloses an anti-collapse hole reinforced gas extraction device and a use method thereof. The circular plate on the 'battery' -shaped plug I is extruded, so that a part of paste permeates into a coal layer hole crack to achieve tight adhesion and fit of the circular plate and a coal layer, the 'battery' -shaped plug I and the 'battery' -shaped plug II achieve the purpose of supporting holes on two sides of a hole sealing area, the valve connector I is opened, a stirring blade, a power pump device, a sealing plate and a sealing cover of a grouting back device are adjusted and controlled, hole sealing slurry is prepared, the slurry in a grouting back tank body and the slurry in the stirring tank body are applied with the same high pressure to force the slurry on two sides to flow to the hole sealing area, the hole crack in the coal layer is better filled, recovery of the slurry and high-pressure filling of the slurry to the hole are achieved, after the slurry is solidified, gas extraction operation is carried out, and the anti-collapse hole strengthening gas extraction process is completed.
Description
Technical Field
The invention relates to an anti-collapse reinforced gas extraction device and a use method thereof, and belongs to the field of coal mine gas extraction.
Background
For the production operation of coal mines, the 'pumping before mining' policy executed by people can not only fundamentally solve the problem of frequent gas disasters, but also be used as clean energy to optimize the energy consumption structure of China. However, the density of hole sealing can seriously affect the gas extraction concentration and efficiency. The factors influencing the sealing compactness are many, one of the factors is that after the gas extraction is carried out for a period of time, when the coal wall around the drill hole is subjected to new stress change, the drill holes on the two sides of the sealing area collapse, the inner side and the outer side of the sealing area are penetrated, the gas extraction concentration and the gas extraction effect are greatly reduced, and the hole collapse prevention reinforced gas extraction device and the use method are provided, so that the problem of hole collapse of the drill holes on the two sides of the sealing area can be effectively solved, and the gas extraction efficiency is improved.
Disclosure of Invention
The technical problem is as follows: the invention aims to solve the problems of hole collapse of underground drill holes of a coal mine, untight plugging of the drill holes and the like, and provides a hole collapse prevention reinforced gas extraction device and a using method thereof.
The technical scheme is as follows: the invention discloses an anti-collapse hole reinforced gas extraction device which comprises an extraction pipeline sleeved with a battery-shaped plug I and a battery-shaped plug II, wherein the battery-shaped plug I and the battery-shaped plug II are oppositely arranged, a hole sealing area is arranged in the middle of the battery-shaped plug I, one ends of a grouting pipe and a slurry return pipe penetrate through the battery-shaped plug I and penetrate into the hole sealing area, the other ends of the grouting pipe and the slurry return pipe are respectively connected with a valve connector I and a connector II, the valve connector I is positioned at the bottom of the slurry return device, and the connector II is positioned on the side face of the slurry return device.
The 'battery' -shaped plug II is composed of a column type pipe, a conical type pipe, a large hole and a blocking piece, one end of the column type pipe is connected with the blocking piece, the other end of the column type pipe is connected with the conical type pipe, the large hole is respectively located on the blocking piece and the conical type pipe, compared with the 'battery' -shaped plug II, the 'battery' -shaped plug I is additionally provided with a circular plate, a small hole I and a small hole II, the small hole I and the small hole II are located on two sides of the large hole in the conical type pipe, the circular plate is sleeved with the other end of the column type pipe, and the inner side of the circular plate is covered with paste.
The grouting and back-grouting device is composed of a grouting tank body, a back-grouting tank body, a through hole, a stirring blade, a power pump device and a sealing cover, wherein the back-grouting tank body is located at the upper end of the grouting and back-grouting device, the grouting tank body is located at the lower end of the grouting and back-grouting device, the power pump and the sealing cover are respectively connected to the upper end of the back-grouting tank body, a sealing plate is arranged at the lower end of the back-grouting tank body, the lower end of the power pump device penetrates through the sealing plate, and the stirring blade is arranged on the inner side of the grouting tank body.
The invention discloses an anti-collapse reinforced gas extraction method, which comprises the following steps:
a. firstly, drilling a conventional borehole in a coal seam by using a drilling machine;
b. the extraction pipeline sleeved with the battery-shaped plug I and the battery-shaped plug II is sent into the conventional drill hole, and a circular plate on the battery-shaped plug I is extruded, so that part of the paste penetrates into cracks of a coal layer hole, the circular plate is tightly adhered and attached to the coal layer, and a connection channel between the interior of the drill hole and the outside is blocked to a certain degree;
c. respectively penetrating one end of a grouting pipe and one end of a back grouting pipe through a first small hole and a second small hole of a battery-shaped plug I and deeply penetrating into a hole sealing area;
d. connecting the grouting pipe with the first valve connector, the grout return pipe and the second connector to enable the grouting pipe and the grout return pipe to be communicated with the grouting and grouting device;
e. the stirring blades are operated to complete the preparation of the hole sealing slurry, the valve connector I and the sealing cover are opened, the power pump device is started, and the hole sealing slurry is pressed into a hole sealing area through the grouting pipe;
f. when the hole sealing slurry flows into the slurry return device through the slurry return pipe, the sealing cover is closed, the sealing plate is opened, and the slurry in the grouting pipe and the slurry return pipe is squeezed by the same high pressure and flows into a hole sealing area, so that the pressurized grouting of the conventional drilling is completed;
g. and after the hole sealing slurry is solidified, performing underground gas extraction operation to finish the anti-collapse reinforced gas extraction process.
Has the beneficial effects that: by adopting the technical scheme, the battery-shaped plug I and the battery-shaped plug II in the anti-collapse hole reinforced gas extraction device can effectively prevent the problem that the collapse hole occurs when the drill holes on the two sides of the plugging area are drilled, after the paste on the side surface of the circular plate of the battery-shaped plug I is extruded, a part of the paste body permeates into the coal seam hole cracks to realize tight adhesion and attachment of the circular plate and the coal seam, a communication channel between the interior of the drill hole and the outside is blocked to a certain degree, the grouting and returning device with the integrated grouting and returning functions can also realize recovery of backflow hole sealing slurry and apply the same high pressure to the hole sealing slurry in the slurry returning tank body and the stirring tank body to force the hole sealing slurry on the two sides to flow to the plugging area, so that the hole cracks in the coal seam are filled better, high-quality sealing of a gas extraction drill hole is realized, and efficient extraction of gas is facilitated.
Drawings
FIG. 1 is a schematic diagram of the grouting configuration of the apparatus of the present invention.
FIG. 2 is a schematic cross-sectional view of the device of the present invention.
Fig. 3 is a structural schematic diagram of the 'battery' -shaped plug I and the 'battery' -shaped plug II.
FIG. 4 is a schematic structural diagram of a grouting device.
Fig. 5 is a theoretical schematic diagram of the grouting device for realizing pressurized grouting.
In the figure: 1. the coal seam, 2. conventional drilling, 3. extraction pipeline, 4. 'battery' -shaped plug I, 5. 'battery' -shaped plug II, 6. grouting pipe, 7. grout returning pipe, 8-1. valve interface I, 8-2. interface II, 9. grout returning device, 10. column pipe, 11. cone pipe, 12. large hole, 13-1. small hole I, 13-2. small hole II, 14. circular plate, 15. paste, 16. block piece, 17. grouting tank, 18. grout returning tank, 19. sealing plate, 20. stirring blade, 21. power pump device, 22. hole sealing area, 23. sealing cover.
The specific implementation mode is as follows:
an embodiment of the present invention is further described below with reference to the accompanying drawings:
as shown in fig. 1-3, the anti-collapse hole reinforced gas extraction device comprises an extraction pipeline 3 sleeved with a 'battery' -shaped plug I4 and a 'battery' -shaped plug II 5, wherein the 'battery' -shaped plug I4 and the 'battery' -shaped plug II 5 are oppositely arranged, a hole sealing area 22 is formed in the middle, one end of a grouting pipe 6 and one end of a slurry return pipe 7 penetrate through the 'battery' -shaped plug I4 and penetrate into the hole sealing area, the other end of the grouting pipe is respectively connected with a valve interface I8-1 and a valve interface II 8-2, the valve interface I8-1 is located at the bottom of a slurry injection and return device 9, and the interface II 8-2 is located on the side face of the slurry injection and return device 9. The 'battery' -shaped plug II 5 is composed of a column pipe 10, a conical pipe 11, a large hole 12 and a blocking piece 16, one end of the column pipe 10 is connected with the blocking piece 16, the other end of the column pipe is connected with the conical pipe 11, the large hole 12 is respectively located on the blocking piece 16 and the conical pipe 11, compared with the 'battery' -shaped plug II 5, a circular plate 14, a small hole I13-1 and a small hole II 13-2 are additionally arranged on the 'battery' -shaped plug I4, the small hole I13-1 and the small hole II 13-2 are located on two sides of the large hole 12 on the conical pipe 11, the circular plate 14 is connected with the other end of the column pipe 10 in a sleeved mode, and a paste 15 covers the inner side of the circular plate 14. The grouting and back-grouting device 9 is composed of a stirring tank body 17, a back-grouting tank body 18, a sealing plate 19, stirring blades 20, a power pump device 21 and a sealing cover 23, the back-grouting tank body 18 is located at the upper end of the grouting and back-grouting device 9, the grouting tank body 17 is located at the lower end of the grouting and back-grouting device 9, the upper end of the back-grouting tank body 18 is connected with the power pump device 21 and the sealing cover 23 respectively, the sealing plate 19 is arranged at the lower end of the back-grouting tank body 18, the lower end of the power pump device 21 penetrates through the sealing plate 19, and the stirring blades 20 are arranged on the inner side of the grouting tank body 17.
The use method of the anti-collapse reinforced gas extraction device comprises the following steps: firstly, a conventional drill hole 2 is drilled in a coal seam 1 by a drilling machine, an extraction pipeline 3 sleeved with a 'battery' -shaped plug I4 and a 'battery' -shaped plug II 5 is sent into the conventional drill hole 2, a circular plate 14 on the 'battery' -shaped plug I4 is extruded, a part of paste 15 permeates into a crack of a hole of the coal seam 1, the circular plate 14 is tightly adhered and attached to the coal seam 1, a communication channel between the interior of the drill hole and the outside is blocked to a certain degree, one end of a grouting pipe 6 and one end of a grout return pipe 7 respectively penetrate through a small hole I13-1 and a small hole II 13-2 of the 'battery' -shaped plug I4 and go deep into a hole sealing area 22, the grouting pipe 6 and a valve connector I8-1, the grout return pipe 7 and a connector II 8-2 are connected, the grouting pipe 6 and the grout return pipe 7 are communicated with a grouting and grouting device 9, a stirring blade 20 is operated to complete the preparation of grout, the valve connector I8-1 and a sealing cover 3 are opened, the power pump device 21 is started, hole sealing slurry is pressed into the hole sealing area 22 through the grouting pipe 7, when the hole sealing slurry flows into the slurry return tank 18 through the slurry return pipe 7, the sealing cover 23 is closed, the sealing plate 19 is opened, the hole sealing slurry in the grouting pipe 6 and the slurry return pipe 7 is squeezed by the same high pressure and flows into the hole sealing area 22, pressurized grouting of the conventional drill hole 2 is completed, after the hole sealing slurry is solidified, underground gas extraction operation is carried out, and the hole collapse prevention reinforced gas extraction process is completed.
Claims (1)
1. A reinforced gas extraction method adopting a hole collapse prevention reinforced gas extraction device is characterized by comprising the following steps: the hole collapse prevention reinforced gas extraction device comprises: the drainage pipeline (3) is sleeved with a 'battery' -shaped plug I (4) and a 'battery' -shaped plug II (5), the 'battery' -shaped plug I (4) and the 'battery' -shaped plug II (5) are oppositely arranged, a hole sealing area (22) is arranged in the middle, one end of a grouting pipe (6) and one end of a slurry return pipe (7) penetrate through the 'battery' -shaped plug I (4) and go deep into the hole sealing area, the other end of the grouting pipe is respectively connected with a valve interface I (8-1) and a valve interface II (8-2), the valve interface I (8-1) is positioned at the bottom of the slurry injection and return device (9), and the interface II (8-2) is positioned on the side face of the slurry injection and return device (9); the 'battery' -shaped plug II (5) is composed of a column type pipe (10), a conical pipe (11), a large hole (12) and a blocking piece (16), one end of the column type pipe (10) is connected with the blocking piece (16), the other end of the column type pipe is connected with the conical pipe (11), the large hole (12) is respectively located on the blocking piece (16) and the conical pipe (11), compared with the 'battery' -shaped plug II (5), the 'battery' -shaped plug I (4) is additionally provided with the circular plate (14), the small hole I (13-1) and the small hole II (13-2) are located on two sides of the large hole (12) on the conical pipe (11), the circular plate (14) is sleeved with the other end of paste of the column type pipe (10), and the inner side of the circular plate (14) is covered with the blocking piece (15); the grouting and slurry returning device (9) is composed of a stirring tank body (17), a slurry returning tank body (18), a sealing plate (19), stirring blades (20), a power pump device (21) and a sealing cover (23), the slurry returning tank body (18) is positioned at the upper end of the grouting and slurry returning device (9), the grouting tank body (17) is positioned at the lower end of the grouting and slurry returning device (9), the upper end of the slurry returning tank body (18) is respectively connected with the power pump device (21) and the sealing cover (23), the sealing plate (19) is arranged at the lower end, the lower end of the power pump device (21) penetrates through the sealing plate (19), and the stirring blades (20) are arranged on the inner side of the grouting tank body (17);
the method for enhancing the gas extraction comprises the following steps of firstly, drilling a conventional borehole (2) in a coal seam (1) by using a drilling machine, and comprising the following steps:
a. the extraction pipeline (3) sleeved with the battery-shaped plug I (4) and the battery-shaped plug II (5) is sent into the conventional drill hole (2), and a circular plate (14) on the battery-shaped plug I (4) is extruded, so that a part of paste (15) permeates into a hole crack of the coal seam (1), the circular plate (14) is tightly adhered and attached to the coal seam (1), and a communication channel between the interior of the drill hole and the outside is blocked to a certain degree;
b. one end of a grouting pipe (6) and one end of a grout returning pipe (7) respectively penetrate through a first small hole (13-1) and a second small hole (13-2) of a battery-shaped plug (4) and deeply penetrate into a hole sealing area (22);
c. connecting the grouting pipe (6) with the valve interface I (8-1), the slurry return pipe (7) and the interface II (8-2) so that the grouting pipe (6) and the slurry return pipe (7) are communicated with the grouting and slurry return device (9);
d. operating the stirring blade (20) to complete the preparation of the hole sealing slurry, opening the valve connector I (8-1) and the sealing cover (23), starting the power pump device (21), and pressing the hole sealing slurry into a hole sealing area (22) through the grouting pipe (6);
e. when the hole sealing slurry flows into the slurry return tank body (18) through the slurry return pipe (7), the sealing cover (23) is closed, the sealing plate (19) is opened, and the slurry in the grouting pipe (6) and the slurry return pipe (7) is squeezed by the same high pressure and flows into the hole sealing area (22), so that pressurized grouting of the conventional drilling hole (2) is completed;
f. and after the hole sealing slurry is solidified, performing underground gas extraction operation to finish the anti-collapse reinforced gas extraction process.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110717624.5A CN113236346B (en) | 2021-06-28 | 2021-06-28 | Anti-collapse reinforced gas extraction device and use method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110717624.5A CN113236346B (en) | 2021-06-28 | 2021-06-28 | Anti-collapse reinforced gas extraction device and use method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113236346A CN113236346A (en) | 2021-08-10 |
| CN113236346B true CN113236346B (en) | 2022-07-26 |
Family
ID=77140991
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110717624.5A Active CN113236346B (en) | 2021-06-28 | 2021-06-28 | Anti-collapse reinforced gas extraction device and use method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113236346B (en) |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2929163Y (en) * | 2006-04-10 | 2007-08-01 | 中国石化股份胜利油田分公司孤东采油厂 | Hydropower compression type packer |
| CN203441525U (en) * | 2013-05-06 | 2014-02-19 | 中国平煤神马能源化工集团有限责任公司天成实业分公司 | Support type special pipe for gas drainage |
| CN204476353U (en) * | 2015-02-06 | 2015-07-15 | 河南工程学院 | A kind of mash gas pumping drilling plugging device |
| CN204511507U (en) * | 2015-04-07 | 2015-07-29 | 安徽理工大学 | A kind of recoverable gas pumping sealing of hole and filled opening device |
| CN206144555U (en) * | 2016-09-20 | 2017-05-03 | 贝兹维仪器(苏州)有限公司 | Wireless test nipple joint |
| CN109882115B (en) * | 2019-04-08 | 2023-11-21 | 贵州盘江精煤股份有限公司 | Constant-pressure grouting device |
| CN210152603U (en) * | 2019-04-18 | 2020-03-17 | 华明国 | Gas drainage drilling plugging structure |
| CN111021960B (en) * | 2019-12-23 | 2021-04-02 | 山西潞安矿业集团慈林山煤业有限公司李村煤矿 | Method for improving stability of extraction drill hole of low-permeability soft coal seam |
| CN211370341U (en) * | 2020-01-07 | 2020-08-28 | 刘付领 | Dust and blowout prevention device for coal mine gas drainage |
| CN111927527B (en) * | 2020-08-12 | 2022-05-17 | 宿州市金鼎安全技术股份有限公司 | Quick gas drilling and extraction device |
| CN111927528A (en) * | 2020-09-07 | 2020-11-13 | 中煤华晋集团有限公司 | Self-adaptive dynamic hole sealing system and hole sealing method thereof |
| CN112228013B (en) * | 2020-09-14 | 2021-10-15 | 山东科技大学 | Device and method for sealing holes with pressure in full-length sieve tube protecting hole in soft coal layer |
-
2021
- 2021-06-28 CN CN202110717624.5A patent/CN113236346B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN113236346A (en) | 2021-08-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102287163B (en) | Drilling-sealing method and sealing device of coal mine underground ultrahigh pressure fracturing hole | |
| CN108678802B (en) | Coal mine drilling, punching and drawing integrated outburst prevention device and method | |
| CN101294500B (en) | Heavy pressure slip-casting hole-sealing method for large-diameter extraction borehole | |
| CN102704984B (en) | Borehole high-concentration gas extraction and drainage method and device thereof | |
| CN102996159B (en) | Multiphase medium plugging device and method for gas extraction drill hole | |
| CN107630717A (en) | The coal seam anti-reflection method that a kind of electric pulse mutually cooperates with coal-bed flooding | |
| CN110578505B (en) | Drilling deslagging and oscillation fracturing gas extraction system and method based on nano fluid | |
| CN109915199A (en) | Gas drainage device and its application method are strengthened in anti-reflection coal seam step by step | |
| CN205063929U (en) | Colliery is sealed in pit and is pressed integration segmentation hydraulic fracturing device | |
| CN109162755A (en) | A kind of coal uncovering method that electric pulse is combined with grouting and reinforcing | |
| CN112031683A (en) | Sand washing and sand carrying lifting production integrated process pipe column and method thereof | |
| CN202689924U (en) | Drilling device of bottom plate of coal mine tunnel | |
| CN111911225A (en) | Drilling and water injection integrated device and method for coal seam | |
| CN113236346B (en) | Anti-collapse reinforced gas extraction device and use method | |
| CN105317397A (en) | Double cloth bags type grouting sealing set and method | |
| CN212958583U (en) | Layered gas injection and layered fracturing pipe column | |
| CN203476278U (en) | Grouting type hole sealing and automatic water discharging device for underground drilling gas extraction | |
| CN107178388A (en) | Pressure coal gas device is taken out in heading pulse | |
| CN104481452A (en) | Method for sealing holes drilled through variable-frequency impulse grouting drilling | |
| CN214616451U (en) | Multifunctional gas extraction and hole sealing device for plugging and reinjecting satellite hole | |
| CN104564105A (en) | Device and method for grouting and reinforcing secondary casing pipe of coal seam floor | |
| CN109184748B (en) | Pressure-controllable grouting equipment and method thereof | |
| CN212774391U (en) | Gas drainage device in coal mine tunnel and grouting part thereof | |
| CN212337240U (en) | Separate-layer liquid drainage gas production pipe column for coal-bed gas well | |
| CN113137204A (en) | Hole sealing device for underground roof drilling and hole sealing method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |