CN111472834A - Method for preventing upward gas extraction borehole from collapsing at fixed point - Google Patents
Method for preventing upward gas extraction borehole from collapsing at fixed point Download PDFInfo
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- CN111472834A CN111472834A CN202010523587.XA CN202010523587A CN111472834A CN 111472834 A CN111472834 A CN 111472834A CN 202010523587 A CN202010523587 A CN 202010523587A CN 111472834 A CN111472834 A CN 111472834A
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- gas extraction
- coal
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- hole
- collapse
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- E—FIXED CONSTRUCTIONS
- E21—EARTH 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
Abstract
The invention discloses a method for preventing an upward gas extraction borehole from collapsing at a fixed point, which comprises the steps of firstly, carrying out in-situ detection on an upward gas extraction borehole crack by using a borehole detector, and determining each easy-to-collapse position and length in the upward gas extraction borehole; push prefabricated cylinder moulded coal in to gas drainage drilling, when cylinder moulded coal propelling movement to the easy position of collapsing of required protection like this, take out the propelling movement pole from the top to gas drainage drilling, cylinder moulded coal is at this moment under self action of gravity, through the solid effect of the card that compresses tightly that two barb structures extend, can fix by oneself and easily collapse the position in the last gas drainage drilling, and the through-hole at center can guarantee the unblocked of gas drainage passageway, has realized that the fixed point of gas drainage drilling is decided length and has prevented collapsing. In addition, the barb structure material is a PVC material, which does not influence the subsequent coal body exploitation, and the components of the cylindrical briquette are similar to those of the coal body, so that the quality of the exploited coal is not influenced, and the quality of the exploited coal is ensured.
Description
Technical Field
The invention relates to a method for preventing collapse of a gas extraction borehole, in particular to a method for preventing collapse of an upward gas extraction borehole at a fixed point.
Background
Because the underground drilling gas extraction has the advantages of simple construction, low cost and the like, the underground drilling gas extraction method is widely applied to gas control of coal mines in China. However, due to the influences of factors such as ground stress and gas pressure, the problem of borehole collapse is serious in the process of gas extraction of the soft coal seam, and the borehole collapse blocks a channel for outward flow of gas, so that the efficient gas extraction and underground gas treatment are obviously influenced, and the safe production of a mine is influenced. The soft coal seam occupies a large proportion in the coal seam which can be mined in China, hole collapse of a drill hole of the soft coal seam is a main problem which restricts efficient extraction of underground gas, hole collapse is mainly prevented by feeding a screen pipe into the drill hole at present, however, residual coal scraps with different degrees exist after the drill hole is drilled, and local collapse of the drill hole of the soft coal seam can occur in a short time, so that the screen pipe cannot penetrate through the hole collapse section of the drill hole to affect efficient extraction of the gas in the drill hole in practical application.
The invention discloses a coal seam drilling collapse prevention device and a collapse prevention method, wherein porous concrete is injected into a section which is easy to collapse of a drilling hole to actively support the drilling hole, the porous concrete has the characteristics of high strength and large porosity, the section which is easy to collapse of the drilling hole can be effectively supported, the porous concrete also has good space pore characteristics, and gas can freely pass through the section.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides the method for preventing the collapse of the upward gas extraction drill hole at a fixed point, which can not only effectively protect the upward gas extraction drill hole from collapse and ensure the smoothness of a gas extraction channel, but also cannot influence the subsequent coal mining, and cannot influence the quality of the mined coal.
In order to achieve the purpose, the invention adopts the technical scheme that: a method for preventing upward gas extraction drill hole from collapsing at fixed points comprises the following specific steps:
A. performing in-situ detection on the cracks of the upward gas extraction drill hole by using a drill hole detector, and determining the position and length of each easy-to-collapse position in the upward gas extraction drill hole by combining the distribution and development condition of the cracks in the drill hole;
B. preparing a plurality of cylindrical coals, wherein a through hole is formed in the center of each cylindrical coal, and the axis of each through hole is coaxial with the axis of each cylindrical coal; two mounting holes are symmetrically formed in the middle of the side wall of the cylindrical coal, a barb structure is arranged in each mounting hole, and one end of each barb structure extends out of the side wall of the cylindrical coal from each mounting hole; the other ends of the two barb structures are connected in the through hole through an elastic sheet, and the two barb structures are in an unstretched initial state; the pushing device is arranged and comprises a pushing rod and a plurality of connecting rods, the pushing rod consists of a rod body, an insertion pipe and a baffle, one end of the insertion pipe is coaxially and fixedly connected with one end of the rod body, the baffle is fixed at the joint of the rod body and the insertion pipe, and the axis of the rod body is perpendicular to the baffle;
C. selecting a cylindrical coal, placing the cylindrical coal on the baffle, and enabling the other end of the insertion pipe to extend into the through hole of the cylindrical coal, so that the cylindrical coal and the push rod are relatively fixed, then determining the deepest position easy to collapse in the upward gas extraction drill hole according to the step A, enabling the push rod to drive the cylindrical coal to start to extend into the upward gas extraction drill hole, enabling the two barb structures to be compressed towards the inside of the through hole under the limiting effect of the inner wall of the upward gas extraction drill hole in the extending process, and enabling the elastic sheet to be stressed and deformed to increase the elasticity of the elastic sheet; then the other end of the push rod is in threaded connection with one connecting rod, the cylindrical coal continues to extend upwards into the gas extraction drill hole, then the connecting rod is in threaded connection with the next connecting rod, the steps are repeated until the cylindrical coal is sent to the top end of the position which is deepest and easy to collapse towards the gas extraction drill hole, the connecting rods and the push rod are sequentially taken out from the top into the gas extraction drill hole, at the moment, the cylindrical coal only receives the action of gravity due to the fact that the push force which is not applied by a baffle plate, and has the trend of moving upwards towards the lower side of the gas extraction drill hole, the two barb structures are under the elastic action of the elastic piece, the two barb structures extend towards the two sides of the cylindrical coal, the two barb structures and the inner wall of the upward gas extraction drill hole are tightly clamped, and the cylindrical coal is fixed at the current position;
D. repeating the step C, selecting another cylindrical coal to be placed below the previous cylindrical coal, and repeating the step C until the length of the placed cylindrical coal is greater than that of the deepest position easy to collapse, so as to finish the fixed-point protection of the position easy to collapse;
E. selecting one position which is closest to the position easy to collapse in the step D from the positions easy to collapse determined in the step A, and then repeating the steps B and C to finish the fixed-point protection of the position easy to collapse; and repeating the steps until the fixed-point protection of all the positions easy to collapse of the upward gas extraction drill hole is completed.
Further, the cylindrical briquette is prepared by mixing coal powder and bentonite, the diameter of the cylindrical briquette is 0.8-0.9 time of the diameter of a drilled hole, and the length of the cylindrical briquette is 0.2-0.4 m; the diameter of the through hole is 0.5-0.6 times of the diameter of the cylindrical briquette.
Further, the diameter that two barb structures expand completely is 1.1 ~ 1.12 times of drilling diameter, and the material of barb structure and flexure strip is the PVC material.
Further, the length of the rod body is 1.15-1.7 m, the length of the insertion tube is 0.15-0.2 m, and the length of the connecting rod is 1-1.5 m.
Compared with the prior art, the method has the advantages that the borehole detector is adopted to carry out in-situ detection on the cracks of the upward gas extraction borehole, and the position and the length of each easy-to-collapse position in the upward gas extraction borehole are determined by combining the distribution and the development condition of the cracks in the borehole, so that the position of the gas extraction borehole needing fixed-point protection can be determined. The cylindrical coal of built-in through-hole is pushed into in the gas drainage drilling hole, and be equipped with the barb structure, when cylindrical coal propelling movement to the position of easily collapsing of required protection like this, take out the propelling movement pole from the top to gas drainage drilling hole, cylindrical coal is under self action of gravity this moment, through the card effect that compresses tightly that two barb structures extended, can fix by oneself and easily collapse the position in last gas drainage drilling hole, the through-hole at center can guarantee the unblocked of gas drainage passageway, the fixed point fixed length that has realized gas drainage drilling prevents collapsing. In addition, the barb structure material is a PVC material, which does not influence the subsequent coal mining, and the components of the cylindrical coal are similar to those of the coal, thereby ensuring the quality of the mined coal. Therefore, the invention not only can effectively protect the upward gas extraction drill hole from collapse, ensure the smoothness of the gas extraction channel, but also can not influence the subsequent coal mining, and simultaneously can not influence the quality of the mined coal.
Drawings
FIG. 1 is a sectional view of a cylindrical briquette of the present invention;
FIG. 2 is a top view of FIG. 1;
FIG. 3 is a schematic view of the construction of the push rod of the present invention;
fig. 4 is a schematic diagram of the deployment of the present invention.
In the figure: 1. cylindrical briquette; 1-1, through holes; 1-2, barb structure; 2. pushing the rod in; 2-1, inserting pipes, 2-2, baffles, 2-3, rod bodies, 3 and upward gas extraction drill holes; 4. a coal seam.
Detailed Description
The present invention will be further explained below.
As shown in fig. 1 to 4, the method comprises the following specific steps:
A. carrying out in-situ detection on the cracks of the upward gas extraction drill hole by using a drill hole detector, and determining each easy-to-collapse position and length in the upward gas extraction drill hole 3 by combining the distribution and development condition of the cracks in the drill hole;
B. preparing a plurality of cylindrical coals 1, wherein the center of each cylindrical coal 1 is provided with a through hole 1-1, and the axis of each through hole 1-1 is coaxial with the axis of each cylindrical coal 1; two mounting holes are symmetrically formed in the middle of the side wall of the cylindrical coal 1, a barb structure 1-2 is arranged in each mounting hole, and one end of each barb structure 1-2 extends out of the side wall of the cylindrical coal 1 from each mounting hole; the other ends of the two barb structures 1-2 are connected in the through hole 1-1 through an elastic sheet, and at the moment, the two barb structures 1-2 are in an unstretched initial state; arranging a pushing device, wherein the pushing device comprises a pushing rod 2 and a plurality of connecting rods, the pushing rod consists of a rod body 2-3, an inserting pipe 2-1 and a baffle 2-2, one end of the inserting pipe 2-1 is coaxially and fixedly connected with one end of the rod body 2-3, the baffle 2-2 is fixed at the joint of the rod body 2-3 and the inserting pipe 2-1, and the axis of the rod body 2-3 is vertical to the baffle 2-2;
C. selecting a cylindrical coal 1, placing the cylindrical coal 1 on a baffle 2-2, and enabling the other end of an insertion pipe 2-1 to extend into a through hole 1-1 of the cylindrical coal 1, so that the cylindrical coal 1 and a push rod 2 are relatively fixed, then determining the deepest easily-collapsed position in an upward gas extraction drill hole 3 according to the step A, enabling the push rod 2 to drive the cylindrical coal 1 to start to extend into the upward gas extraction drill hole 3, enabling the two barb structures 1-2 to be limited by the inner wall of the upward gas extraction drill hole 3 in the extending process, enabling the two barb structures 1-2 to be compressed towards the inside of the through hole 1-1, and enabling the elastic sheet to be deformed under stress to increase the elasticity of the elastic sheet; then the other end of the push rod 2 is connected with a connecting rod through threads, the cylindrical coal 1 is continuously extended upwards into the gas extraction drill hole 3, then the connecting rod is connected with the next connecting rod through threads, the steps are repeated until the cylindrical coal 1 is sent to the top end of the deepest position easy to collapse towards the gas extraction drill hole 3, the connecting rods and the push rod 2 are sequentially taken out from the gas extraction drill hole 3 from the top, at the moment, the cylindrical coal 1 has the tendency of moving upwards towards the lower part of the gas extraction drill hole 3 due to the fact that the push force applied by the non-baffle plates 2-2 is only under the action of gravity, the two barb structures 1-2 are under the action of the elastic force of the elastic pieces, and the two barb structures 1-2 are enabled to extend towards the two sides of the cylindrical coal 1, further enabling the two barb structures 1-2 to be tightly pressed and clamped with the inner wall of the upward gas extraction drill hole 3, and enabling the cylindrical coal 1 to be fixed at the current position;
D. repeating the step C, selecting another cylindrical coal 1 to be placed below the previous cylindrical coal, and repeating the step C until the length of the placed cylindrical coal 1 is greater than that of the deepest position easy to collapse, so as to finish the fixed point protection of the position easy to collapse;
E. selecting one position which is closest to the position easy to collapse in the step D from the positions easy to collapse determined in the step A, and then repeating the steps B and C to finish the fixed-point protection of the position easy to collapse; and repeating the steps until the fixed-point protection of all the positions easy to collapse of the upward gas extraction drill hole is completed.
Further, the cylindrical briquette 1 is prepared by mixing pulverized coal and bentonite according to a known proportion, the diameter of the cylindrical briquette 1 is 0.8-0.9 times of the diameter of a drilled hole, and the length of the cylindrical briquette 1 is 0.2-0.4 m; the diameter of the through hole 1-1 is 0.5-0.6 times of the diameter of the cylindrical briquette 1.
Further, the diameter that two barb structures 1-2 expand completely is 1.1 ~ 1.12 times of drilling diameter, and the material of barb structure 1-2 and flexure strip is the PVC material.
Further, the length of the rod body 2-3 is 1.15-1.7 m, the length of the insertion tube 2-1 is 0.15-0.2 m, and the length of the connecting rod is 1-1.5 m.
Claims (4)
1. A method for preventing an upward gas extraction borehole from collapsing at a fixed point is characterized by comprising the following specific steps:
A. performing in-situ detection on the cracks of the upward gas extraction drill hole by using a drill hole detector, and determining the position and length of each easy-to-collapse position in the upward gas extraction drill hole by combining the distribution and development condition of the cracks in the drill hole;
B. preparing a plurality of cylindrical coals, wherein a through hole is formed in the center of each cylindrical coal, and the axis of each through hole is coaxial with the axis of each cylindrical coal; two mounting holes are symmetrically formed in the middle of the side wall of the cylindrical coal, a barb structure is arranged in each mounting hole, and one end of each barb structure extends out of the side wall of the cylindrical coal from each mounting hole; the other ends of the two barb structures are connected in the through hole through an elastic sheet, and the two barb structures are in an unstretched initial state; the pushing device is arranged and comprises a pushing rod and a plurality of connecting rods, the pushing rod consists of a rod body, an insertion pipe and a baffle, one end of the insertion pipe is coaxially and fixedly connected with one end of the rod body, the baffle is fixed at the joint of the rod body and the insertion pipe, and the axis of the rod body is perpendicular to the baffle;
C. selecting a cylindrical coal, placing the cylindrical coal on the baffle, and enabling the other end of the insertion pipe to extend into the through hole of the cylindrical coal, so that the cylindrical coal and the push rod are relatively fixed, then determining the deepest position easy to collapse in the upward gas extraction drill hole according to the step A, enabling the push rod to drive the cylindrical coal to start to extend into the upward gas extraction drill hole, enabling the two barb structures to be compressed towards the inside of the through hole under the limiting effect of the inner wall of the upward gas extraction drill hole in the extending process, and enabling the elastic sheet to be stressed and deformed to increase the elasticity of the elastic sheet; then the other end of the push rod is in threaded connection with one connecting rod, the cylindrical coal continues to extend upwards into the gas extraction drill hole, then the connecting rod is in threaded connection with the next connecting rod, the steps are repeated until the cylindrical coal is sent to the top end of the position which is deepest and easy to collapse towards the gas extraction drill hole, the connecting rods and the push rod are sequentially taken out from the top into the gas extraction drill hole, at the moment, the cylindrical coal only receives the action of gravity due to the fact that the push force which is not applied by a baffle plate, and has the trend of moving upwards towards the lower side of the gas extraction drill hole, the two barb structures are under the elastic action of the elastic piece, the two barb structures extend towards the two sides of the cylindrical coal, the two barb structures and the inner wall of the upward gas extraction drill hole are tightly clamped, and the cylindrical coal is fixed at the current position;
D. repeating the step C, selecting another cylindrical coal to be placed below the previous cylindrical coal, and repeating the step C until the length of the placed cylindrical coal is greater than that of the deepest position easy to collapse, so as to finish the fixed-point protection of the position easy to collapse;
E. selecting one position which is closest to the position easy to collapse in the step D from the positions easy to collapse determined in the step A, and then repeating the steps B and C to finish the fixed-point protection of the position easy to collapse; and repeating the steps until the fixed-point protection of all the positions easy to collapse of the upward gas extraction drill hole is completed.
2. The method for preventing the upward gas extraction borehole from collapsing at a fixed point according to claim 1, wherein the cylindrical briquette is prepared by mixing coal powder and bentonite, the diameter of the cylindrical briquette is 0.8-0.9 times of the diameter of the borehole, and the length of the cylindrical briquette is 0.2-0.4 m; the diameter of the through hole is 0.5-0.6 times of the diameter of the cylindrical briquette.
3. The method for preventing the upward gas extraction borehole from collapsing at a fixed point according to claim 1, wherein the diameter of the two barb structures which are completely unfolded is 1.1-1.12 times of the diameter of the borehole, and the barb structures and the elastic pieces are made of PVC materials.
4. The method for preventing the upward gas extraction borehole from collapsing at a fixed point according to claim 1, wherein the length of the rod body is 1.15-1.7 m, the length of the insertion pipe is 0.15-0.2 m, and the length of the connecting rod is 1-1.5 m.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010523587.XA CN111472834B (en) | 2020-06-10 | 2020-06-10 | Method for preventing upward gas extraction borehole from collapsing at fixed point |
| LU500251A LU500251B1 (en) | 2020-06-10 | 2021-06-07 | Method for fixed-point collapse protection of upward gas extraction borehole |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010523587.XA CN111472834B (en) | 2020-06-10 | 2020-06-10 | Method for preventing upward gas extraction borehole from collapsing at fixed point |
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| CN111472834A true CN111472834A (en) | 2020-07-31 |
| CN111472834B CN111472834B (en) | 2021-11-09 |
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| LU (1) | LU500251B1 (en) |
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| CN109736875A (en) * | 2018-12-11 | 2019-05-10 | 太原理工大学 | A kind of coal bed drilling anti-collapse device and anti-collapse method |
| CN110454115A (en) * | 2019-09-10 | 2019-11-15 | 河南理工大学 | A kind of mash gas pumping drilling hole sealing device and method for sealing |
| CN111021960A (en) * | 2019-12-23 | 2020-04-17 | 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 |
-
2020
- 2020-06-10 CN CN202010523587.XA patent/CN111472834B/en active Active
-
2021
- 2021-06-07 LU LU500251A patent/LU500251B1/en active IP Right Grant
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102635393A (en) * | 2012-05-09 | 2012-08-15 | 中国矿业大学 | Combined hole sealing method for gas extracting and drilling delaying self-expansion capsule-paste |
| CN103195471A (en) * | 2013-04-22 | 2013-07-10 | 中国矿业大学 | Method for preventing drilling collapse of downhole coal bed |
| CN205714086U (en) * | 2016-03-07 | 2016-11-23 | 安徽理工大学 | A kind of mash gas pumping drilling fixed point aperture guard device |
| CN105804691A (en) * | 2016-03-28 | 2016-07-27 | 中国矿业大学 | Pipe-free hole sealing method for mining gas extraction drill hole |
| CN207229158U (en) * | 2017-10-13 | 2018-04-13 | 临沂矿业集团有限责任公司 | Colliery or rock mass gas pumping test equipment |
| CN107654255A (en) * | 2017-11-06 | 2018-02-02 | 兖矿贵州能化有限公司 | A kind of extraction borehole pinpoints guard aperture anti-collapse device |
| CN207960570U (en) * | 2017-12-20 | 2018-10-12 | 中国矿业大学(北京) | A kind of mash gas pumping drilling Stability Maintenance material and installation aiding device |
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| Publication number | Publication date |
|---|---|
| LU500251B1 (en) | 2021-12-07 |
| CN111472834B (en) | 2021-11-09 |
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