CN111255508B - Method for ensuring smoothness of gas extraction channel of soft coal seam - Google Patents
Method for ensuring smoothness of gas extraction channel of soft coal seam Download PDFInfo
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- CN111255508B CN111255508B CN202010170917.1A CN202010170917A CN111255508B CN 111255508 B CN111255508 B CN 111255508B CN 202010170917 A CN202010170917 A CN 202010170917A CN 111255508 B CN111255508 B CN 111255508B
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- 239000003245 coal Substances 0.000 title claims abstract description 53
- 238000000605 extraction Methods 0.000 title claims abstract description 32
- 238000000034 method Methods 0.000 title claims abstract description 16
- 238000005553 drilling Methods 0.000 claims abstract description 31
- 230000005484 gravity Effects 0.000 claims abstract description 11
- 239000004484 Briquette Substances 0.000 claims description 88
- WSNMPAVSZJSIMT-UHFFFAOYSA-N COc1c(C)c2COC(=O)c2c(O)c1CC(O)C1(C)CCC(=O)O1 Chemical compound COc1c(C)c2COC(=O)c2c(O)c1CC(O)C1(C)CCC(=O)O1 WSNMPAVSZJSIMT-UHFFFAOYSA-N 0.000 claims description 9
- 238000005096 rolling process Methods 0.000 claims description 9
- 239000000843 powder Substances 0.000 claims description 5
- FGUUSXIOTUKUDN-IBGZPJMESA-N C1(=CC=CC=C1)N1C2=C(NC([C@H](C1)NC=1OC(=NN=1)C1=CC=CC=C1)=O)C=CC=C2 Chemical compound C1(=CC=CC=C1)N1C2=C(NC([C@H](C1)NC=1OC(=NN=1)C1=CC=CC=C1)=O)C=CC=C2 FGUUSXIOTUKUDN-IBGZPJMESA-N 0.000 claims description 3
- 238000007789 sealing Methods 0.000 claims description 3
- 230000000694 effects Effects 0.000 abstract description 8
- 238000012856 packing Methods 0.000 abstract 1
- 239000000463 material Substances 0.000 description 4
- 238000002360 preparation method Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000005065 mining Methods 0.000 description 2
- 238000010276 construction Methods 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
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- 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
- E21B33/00—Sealing or packing boreholes or wells
- E21B33/10—Sealing or packing boreholes or wells in the borehole
- E21B33/12—Packers; Plugs
-
- 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
- E21B7/00—Special methods or apparatus for drilling
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- 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)
- Solid Fuels And Fuel-Associated Substances (AREA)
Abstract
The invention discloses a method for ensuring the smoothness of a gas extraction channel of a soft coal seam, which comprises the steps of sequentially filling small-size perforated briquettes, medium-size perforated briquettes and large-size perforated briquettes into downward drilled holes, wherein spherical hollow structures are arranged inside the various types of perforated briquettes and are communicated with the outside through vent holes, and the various types of perforated briquettes can play a certain supporting role on the downward drilled holes after the drilled holes are filled, so that the possibility of collapse and deformation of the downward drilled holes is reduced; in addition, because the coal balls are spherical, gaps still exist after the coal balls are directly contacted with each other in the drill holes, and gas in the coal seam forms a gas extraction channel through gaps of the coal balls with holes of various types, the vent holes and the spherical hollow structure in the coal seam, so that the gas extraction is smooth; and all rely on the inclination of downward drilling during the packing, under the effect of self gravity, roll into and protect the support in the downward drilling, need not special erection equipment, consequently the field usage of being convenient for has extensive practicality.
Description
Technical Field
The invention relates to a method for ensuring a gas extraction channel to be smooth, in particular to a method for ensuring the gas extraction channel of a soft coal seam to be smooth.
Background
According to statistics, 52% of mines in China at present belong to high-gas mines, and gas treatment is a premise for guaranteeing safe and efficient production of the mines. However, the proportion of the soft coal seam in China is very high, the main mining coal seams in many mining areas belong to soft, low-permeability and high-gas coal seams, and many mines have coal and gas outburst risks. The construction drilling is an effective means for controlling the gas by pre-pumping the gas in the coal seam in advance, and is also a measure commonly adopted by each coal mine at present. However, in a soft coal seam, more than 90% of gas extraction holes are deformed, collapsed in a long distance or even closed in short-time extraction after being formed, so that gas emission and flowing channels are blocked, and the gas extraction effect is seriously influenced. In addition, in order to effectively treat gas in a mine, the number of constructed extraction holes is large, the investment of manpower, capital and time is large, the cost of a single hole is high, and once the extraction drill hole is blocked, the drilling treatment needs to be carried out again, so that the gas extraction effect is seriously mismatched with the gas treatment investment.
In order to solve the problems, Chinese invention patents with patent numbers of ZL201210056522.4 and ZL201210056441.4 respectively disclose a cooperative and distributed drilling and protection integrated system and a using method, and the two invention patents adopt different methods to protect a hole pipe in the whole process of a gas extraction drill hole, so that the effect of gas extraction caused by collapse of the drill hole is prevented. However, both of the two methods require the preparation of a specific hole-protecting pipe and the effect of protecting the hole-protecting pipe in the gas drilled hole can be achieved only by adopting the mutual cooperation of multiple devices, so that the two methods have the disadvantages of large capital investment, time and labor waste, complex field operation and no wide applicability.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a method for ensuring the smoothness of a gas extraction channel of a soft coal seam, which adopts the mode that a small-size coal ball with holes, a medium-size coal ball with holes and a large-size coal ball with holes are sequentially filled in a downward drilling hole, thereby ensuring the smoothness of the gas extraction channel and improving the gas extraction effect.
In order to achieve the purpose, the invention adopts the technical scheme that: a method for ensuring smooth gas extraction channel of a soft coal seam comprises the following specific steps:
a. determining a position arrangement downward borehole according to the coal seam inclination angle condition, and enabling the inclination angle between the downward borehole and the horizontal plane to be maximum on the basis of not influencing a borehole extraction control area through calculation;
b. placing the prepared small-size perforated briquette at an orifice of a downward drill hole, giving an initial kinetic energy to the small-size perforated briquette, and rolling the small-size perforated briquette into the bottom of the drill hole under the action of self gravity for filling; the small-size perforated briquette is internally provided with a spherical hollow structure I, a plurality of vent holes I are uniformly distributed on the surface of the small-size perforated briquette, the spherical hollow structure I is communicated with the outside through the vent holes I, and the diameter of the small-size perforated briquette is 0.5-0.6 times of the diameter of a downward drilling hole;
c. repeating the step b until the length of the downward drill hole filled by the small-size perforated briquette is 1/3-2/5 of the total length of the downward drill hole, and stopping filling the small-size perforated briquette;
d. placing the prepared medium-size perforated briquette in an orifice of a downward drill hole, giving an initial kinetic energy to the medium-size perforated briquette, and rolling the medium-size perforated briquette into the drill hole under the action of self gravity for filling; the middle-size perforated briquette is internally provided with a spherical hollow structure II, the surface of the middle-size perforated briquette is uniformly provided with a plurality of vent holes II, the spherical hollow structure II is communicated with the outside through the vent holes II, and the diameter of the middle-size perforated briquette is 0.6-0.7 times of that of a downward drilling hole;
e. repeating the step d until the length of the downward drill hole filled by the medium-size perforated briquette is 1/3-2/5 of the total length of the downward drill hole, and stopping filling the medium-size perforated briquette;
f. placing the prepared large-size perforated briquette in an orifice of a downward drill hole, giving an initial kinetic energy to the large-size perforated briquette, and rolling the large-size perforated briquette into the drill hole under the action of self gravity for filling; the large-size perforated briquette is internally provided with a spherical hollow structure III, the surface of the large-size perforated briquette is uniformly provided with a plurality of vent holes III, the spherical hollow structure III is communicated with the outside through each vent hole III, and the diameter of the large-size perforated briquette is 0.7-0.85 times of the diameter of a downward drilling hole;
g. and f, repeating the step f until the distance between the filled large-size perforated briquettes and the hole opening of the downward drilling hole is 8-10 m, stopping filling the large-size perforated briquettes, and using the length for subsequent sealing of the downward drilling hole.
Further, the diameter of the spherical hollow structure I is 1/2-3/5 of the diameter of a small-size perforated briquette; the diameter of the vent I is 2 mm-3 mm; the number of the air holes I on the surface of the small-size perforated briquette is 0.4-0.5 per square centimeter.
Further, the diameter of the spherical hollow structure II is 3/5-2/3 of the diameter of a medium-size perforated briquette; the diameter of the vent hole II is 3-4 mm; the number of the vent holes II on the surface of the medium-size perforated briquette is 0.3-0.4 per square centimeter.
Further, the diameter of the spherical hollow structure III is 2/3-3/4 of the diameter of a large-size perforated briquette; the diameter of the vent hole III is 4-5 mm; the number of the vent holes III on the surface of the large-size perforated briquette is 0.2-0.3 per square centimeter.
Furthermore, the preparation materials of the small-size perforated briquette, the medium-size perforated briquette and the large-size perforated briquette are all coal powder produced by coal beds.
Compared with the prior art, the invention adopts a mode of sequentially filling small-size perforated briquettes, medium-size perforated briquettes and large-size perforated briquettes, wherein the perforated briquettes of various types are internally provided with spherical hollow structures and are communicated with the outside through vent holes, the vent holes are uniformly distributed and have the diameter of 2-5 mm, and the perforated briquettes of various types can play a certain supporting role in downward drilling after filling the drilling holes, thereby reducing the possibility of collapse and deformation of the drilling holes; in addition, because the coal balls are spherical, gaps still exist after the coal balls are directly contacted with each other in the drill holes, and gas in the coal seam forms a gas extraction channel through gaps of the coal balls with holes of various types, the vent holes and the spherical hollow structure in the coal seam, so that the gas extraction is smooth; if the drill hole collapses, the small coal blocks which can collapse can only block part of the vent holes and can not block all the vent holes, so that the formed gas extraction channel can be kept smooth, and the gas can be efficiently extracted for a long time. The perforated briquettes are divided into small perforated briquettes, medium perforated briquettes and large perforated briquettes, and the design of sequentially filling from inside to outside of the drill hole by small, medium and large makes the gas extraction channel formed by the perforated briquettes sequentially enlarged, accord with the rule that the gas flow in the drill hole is gradually increased, so that the gas extraction efficiency is high, and the gas extraction effect is good. In addition, all rely on the inclination of downward drilling when the foraminiferous briquette of various models is filled, under the effect of self gravity, roll into and protect the support in the downward drilling, it need not special erection equipment, just can ensure that gas takes out and takes out that the passageway is smooth and easy, therefore whole implementation process convenient operation is simple, and the field usage of being convenient for has extensive practicality.
Drawings
FIG. 1 is a structural sectional view of a small-size perforated briquette according to the present invention;
FIG. 2 is a schematic view of a downhole tool for downhole protection using the present invention.
In the figure: 1. 2, drilling downwards, 3, a small-size coal ball with holes, 4, a middle-size coal ball with holes, 5, a large-size coal ball with holes, 3-1 and an air vent I; 3-2 and a spherical hollow structure I.
Detailed Description
The present invention will be further explained below.
As shown in fig. 1 to 2, the method comprises the following specific steps:
a. determining a position arrangement downward borehole 2 according to the inclination angle condition of the coal seam 1, and enabling the inclination angle between the downward borehole 2 and the horizontal plane to be maximum on the basis of not influencing a borehole extraction control area through calculation;
b. placing the prepared small-size coal ball with holes 3 at an orifice of a downward drilling hole 2, giving an initial kinetic energy to the small-size coal ball with holes 3, and rolling the small-size coal ball with holes 3 into the bottom of the drilling hole under the action of self gravity for filling; the small-size perforated briquette 3 is internally provided with a spherical hollow structure I3-2, the surface of the small-size perforated briquette is uniformly provided with a plurality of vent holes I3-1, the spherical hollow structure I3-2 is communicated with the outside through the vent holes I3-1, and the diameter of the small-size perforated briquette 3 is 0.5-0.6 time of that of the downward drilling hole 2;
c. repeating the step b until the length of the downward drill hole filled with the small-size perforated briquette 3 is 1/3-2/5 of the total length of the downward drill hole 2, and stopping filling the small-size perforated briquette 3;
d. placing the prepared medium-size perforated briquette 4 at an orifice of a downward drilling hole 2, giving an initial kinetic energy to the medium-size perforated briquette 4, and rolling the medium-size perforated briquette 4 into the drilling hole under the action of self gravity for filling; the middle-size perforated briquette 4 is internally provided with a spherical hollow structure II, the surface of the middle-size perforated briquette is uniformly provided with a plurality of vent holes II, the spherical hollow structure II is communicated with the outside through the vent holes II, and the diameter of the middle-size perforated briquette 4 is 0.6-0.7 times of that of the downward drilling hole 2;
e. repeating the step d until the length of the downward drill hole 2 filled with the medium-size perforated briquette 4 is 1/3-2/5 of the total length of the downward drill hole 2, and stopping filling the medium-size perforated briquette 4;
f. placing the prepared large-size coal balls with holes 5 at the openings of the downward drill holes 2, giving an initial kinetic energy to the large-size coal balls with holes 5, and rolling the large-size coal balls with holes 5 into the drill holes under the action of self gravity for filling; the large-size perforated briquette 5 is internally provided with a spherical hollow structure III, the surface of the large-size perforated briquette is uniformly provided with a plurality of vent holes III, the spherical hollow structure III is communicated with the outside through each vent hole III, and the diameter of the large-size perforated briquette 5 is 0.7-0.85 times of that of the downward drilling hole 2;
g. and f, repeating the step f until the distance between the filled large-size perforated briquette 5 and the orifice of the downward drilling hole 2 is 8-10 m, stopping filling the large-size perforated briquette 5, and using the length for sealing the downward drilling hole 2 subsequently.
Further, the diameter of the spherical hollow structure I3-2 is 1/2-3/5 of the diameter of the small-size perforated briquette 3; the diameter of the vent I3-1 is 2 mm-3 mm; the number of the air holes I3-1 on the surface of the small-size perforated briquette 3 is 0.4-0.5 per square centimeter.
Further, the diameter of the spherical hollow structure II is 3/5-2/3 of the diameter of the medium-size perforated briquette 4; the diameter of the vent hole II is 3-4 mm; the number of the vent holes II on the surface of the medium-size perforated briquette 4 is 0.3-0.4 per square centimeter.
Further, the diameter of the spherical hollow structure III is 2/3-3/4 of the diameter of the large-size perforated briquette 5; the diameter of the vent hole III is 4-5 mm; the number of the vent holes III on the surface of the large-size perforated briquette 5 is 0.2-0.3 per square centimeter.
The perforated briquettes of various models can be prepared from various materials meeting the required supporting force, and preferably, the preparation materials of the small-size perforated briquettes 3, the medium-size perforated briquettes 4 and the large-size perforated briquettes 5 are all coal powder produced by a coal bed, so that the coal powder is wide in source, convenient to manufacture and low in cost, and the coal powder is a material of the coal bed, and cannot influence the quality of coal bodies produced by later-stage coal body extraction after gas extraction is finished (namely, the perforated briquettes of various models can be exploited as the coal bodies).
Claims (2)
1. A method for ensuring the smoothness of a gas extraction channel of a soft coal seam is characterized by comprising the following specific steps:
a. determining a position arrangement downward borehole according to the coal seam inclination angle condition, and enabling the inclination angle between the downward borehole and the horizontal plane to be maximum on the basis of not influencing a borehole extraction control area through calculation;
b. placing the prepared small-size perforated briquette at an orifice of a downward drill hole, giving an initial kinetic energy to the small-size perforated briquette, and rolling the small-size perforated briquette into the bottom of the drill hole under the action of self gravity for filling; the small-size perforated briquette is internally provided with a spherical hollow structure I, a plurality of vent holes I are uniformly distributed on the surface of the small-size perforated briquette, the spherical hollow structure I is communicated with the outside through the vent holes I, and the diameter of the small-size perforated briquette is 0.5-0.6 times of the diameter of a downward drilling hole; the diameter of the spherical hollow structure I is 1/2-3/5 of the diameter of a small-size perforated briquette; the diameter of the vent I is 2 mm-3 mm; the number of the air holes I on the surface of the small-size perforated briquette is 0.4-0.5 per square centimeter;
c. repeating the step b until the length of the downward drill hole filled by the small-size perforated briquette is 1/3-2/5 of the total length of the downward drill hole, and stopping filling the small-size perforated briquette;
d. placing the prepared medium-size perforated briquette in an orifice of a downward drill hole, giving an initial kinetic energy to the medium-size perforated briquette, and rolling the medium-size perforated briquette into the drill hole under the action of self gravity for filling; the middle-size perforated briquette is internally provided with a spherical hollow structure II, the surface of the middle-size perforated briquette is uniformly provided with a plurality of vent holes II, the spherical hollow structure II is communicated with the outside through the vent holes II, and the diameter of the middle-size perforated briquette is 0.6-0.7 times of that of a downward drilling hole; the diameter of the spherical hollow structure II is 3/5-2/3 of the diameter of a medium-size perforated briquette; the diameter of the vent hole II is 3-4 mm; the number of the vent holes II on the surface of the medium-size perforated briquette is 0.3-0.4 per square centimeter;
e. repeating the step d until the length of the downward drill hole filled by the medium-size perforated briquette is 1/3-2/5 of the total length of the downward drill hole, and stopping filling the medium-size perforated briquette;
f. placing the prepared large-size perforated briquette in an orifice of a downward drill hole, giving an initial kinetic energy to the large-size perforated briquette, and rolling the large-size perforated briquette into the drill hole under the action of self gravity for filling; the large-size perforated briquette is internally provided with a spherical hollow structure III, the surface of the large-size perforated briquette is uniformly provided with a plurality of vent holes III, the spherical hollow structure III is communicated with the outside through each vent hole III, and the diameter of the large-size perforated briquette is 0.7-0.85 times of the diameter of a downward drilling hole; the diameter of the spherical hollow structure III is 2/3-3/4 of the diameter of a large-size perforated briquette; the diameter of the vent hole III is 4-5 mm; the number of the vent holes III on the surface of the large-size perforated briquette is 0.2-0.3 per square centimeter;
g. and f, repeating the step f until the distance between the filled large-size perforated briquettes and the hole opening of the downward drilling hole is 8-10 m, stopping filling the large-size perforated briquettes, and using the length for subsequent sealing of the downward drilling hole.
2. The method for ensuring the smoothness of the gas extraction channel of the soft coal seam according to claim 1, wherein the small-size perforated briquette, the medium-size perforated briquette and the large-size perforated briquette are all made of coal powder produced by a coal seam.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202010170917.1A CN111255508B (en) | 2020-03-12 | 2020-03-12 | Method for ensuring smoothness of gas extraction channel of soft coal seam |
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| CN111255508B true CN111255508B (en) | 2021-07-27 |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN102116168B (en) * | 2011-01-26 | 2012-12-05 | 河南理工大学 | Gas drainage system and method for hyposmosis soft coal seams |
| CN102587961B (en) * | 2012-04-10 | 2013-12-25 | 中国矿业大学 | Feeding method for hole protecting pipe for soft coal seam gas extraction hole |
| CN103195471B (en) * | 2013-04-22 | 2015-05-20 | 中国矿业大学 | Method for preventing drilling collapse of downhole coal bed |
| CN103912304A (en) * | 2014-04-23 | 2014-07-09 | 重庆市能源投资集团科技有限责任公司 | Method for locally extracting gas of soft coal seams |
| CN104879159B (en) * | 2015-06-11 | 2017-07-28 | 河南理工大学 | A kind of devices and methods therefor of weak seam stope anti-reflection mash gas extraction |
| CN108301807B (en) * | 2018-04-24 | 2020-01-24 | 中煤科工集团重庆研究院有限公司 | Hole wall fixing device for gas extraction drill hole of soft coal seam and construction method |
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Address after: 221018 Lishui Road, Yunlong District, Xuzhou, Jiangsu 2 Patentee after: XUZHOU University OF TECHNOLOGY Address before: 221000 No.18, South Third Ring Road, Quanshan District, Xuzhou City, Jiangsu Province Patentee before: XUZHOU University OF TECHNOLOGY |
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Application publication date: 20200609 Assignee: JIANGSU HUAMIAO ELECTRONIC TECHNOLOGY Co.,Ltd. Assignor: XUZHOU University OF TECHNOLOGY Contract record no.: X2023320000182 Denomination of invention: A Method to Ensure Smooth Gas Extraction Channel in Soft Coal Seams Granted publication date: 20210727 License type: Common License Record date: 20230731 |