CN112443351A - Precise outburst elimination method for cross-section coal uncovering of rock cross - Google Patents
Precise outburst elimination method for cross-section coal uncovering of rock cross Download PDFInfo
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- CN112443351A CN112443351A CN202011311046.7A CN202011311046A CN112443351A CN 112443351 A CN112443351 A CN 112443351A CN 202011311046 A CN202011311046 A CN 202011311046A CN 112443351 A CN112443351 A CN 112443351A
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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 precise outburst elimination method for cross-section coal uncovering of a rock cross, which comprises the following steps: firstly, constructing drill sites on two sides of a coal uncovering position of a first cross-cut rock gate at an upper section, constructing a plurality of bedding long drill holes, and controlling the range of at least 12m outside the contour line of a roadway of two cross-cuts and a cross-cut tunnel of a third cross-cut rock gate to be uncovered at a lower section; secondly, a directional drilling machine or a high-power and high-torque drilling machine is adopted to be matched with a drilling inclinometer to monitor the drilling track in real time in the bedding long drilling construction process, so that the constructed bedding long drilling is ensured to completely cover a plurality of rock cross coal uncovering concentrated gas pre-pumping areas, and the gas control range is accurately controlled; and thirdly, after the upper section of the rock portal I is drilled along the bedding through construction, after the extraction reaches the standard, the construction effect inspection holes are inspected when the tunneling working faces of the lower section of the rock portal II and the rock portal III are 7m away from the normal direction of the coal bed, and after the fact that no outburst danger exists is confirmed, the lower section of the rock portal II and the rock portal III can be directly used for coal uncovering operation.
Description
Technical Field
The invention relates to a gas treatment method, in particular to a precise outburst elimination method for cross-section coal uncovering of a rock cross, and belongs to the technical field of coal mine gas treatment.
Background
Coal mine gas is associated gas in the coal mining process, the gas accident threat is faced at the time of underground coal mining, China is the most serious country of outburst disasters in the world, the accident proportion is close to 50%, mining conditions in southwest mining areas are particularly complex, the coal and gas outburst accidents are serious disaster areas, more than 80% of the coal and gas outburst accidents occur in the rock cross-cut coal uncovering period, and the coal and gas outburst accident prevention method has the characteristics of high outburst strength, serious accident hazard and the like.
Coal and gas outburst is unstable release of gas energy and stress energy under the comprehensive action of factors such as ground stress, physical and mechanical properties of the gas and the coal, and is characterized in that a large amount of coal rock and gas are thrown into a mining space in a very short time, and the harm is very serious. During the cross-cut coal uncovering period, the front of the working face is blocked by a protected rock pillar, gas in the coal body is not fully released, the coal body is in a stress concentration and high gas concentration state, gas treatment technical measures are not in place, extraction is not up to the standard, and the gas pressure cannot be effectively reduced, so that the cross-cut coal uncovering method is the main reason for large outburst strength and serious harm in the cross-cut coal uncovering process.
In coal and gas outburst accidents, the main reason is caused by that gas extraction in a coal outburst area is not up to standard when a coal outburst layer is uncovered by mistake or a cross cut coal uncovering area is uncovered by a stone, and the safety production of a mine is seriously threatened. At present, the regional outburst prevention measure for rock cross-cut coal uncovering mainly comprises pre-pumping gas in a coal uncovering region before rock cross-cut coal uncovering, construction cross-layer drilling is used as the regional outburst prevention measure, the project amount is large, the construction period is long, the tunneling efficiency is low during the rock cross-cut coal uncovering period, rapid tunneling is difficult to achieve, and the safety and the rapid development of a mine are influenced.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the method comprises the steps of constructing a drill site in a coal seam exposed by a rock gate in an upper (lower) section, pre-pumping gas in a coal uncovering area by a plurality of rock gate construction bedding long drill holes of a downward (upper) section to be uncovered, ensuring that the gas drill holes in the cross-section pre-pumping coal uncovering area are controlled in place by a high-power and high-torque drilling machine matched with a drill hole inclinometer, and realizing gas control of the plurality of rock gate coal uncovering areas so as to eliminate coal and gas outburst danger in the coal uncovering area. And then when effectively preventing coal and gas outburst occurence of failure for the tunnel construction progress during rock cross-cut coal uncovering, the effectual problem of solving above-mentioned existence.
The technical scheme of the invention is as follows: a cross-section coal uncovering accurate outburst elimination method for a rock cross, the method comprises the following steps:
firstly, when an upper section of a rock gate I is in place or a coal bed is uncovered, two lower section of rock gates II and lower section of rock gates III which are being developed or are about to be developed are arranged on a lower section of the coal bed, drilling fields are constructed on two sides of a coal uncovering position of the upper section of the rock gate I, a plurality of bedding long drilling holes are constructed (the number of the drilling holes is determined according to the distance between the layers of the rock gates of the upper section and the lower section and the roadway arrangement condition of the rock gates about to be uncovered), and the range of at least 12m outside the roadway outline of the two lower section of rock gates II and the lower section of rock gates III in which the coal is about to be uncovered in the;
secondly, a directional drilling machine or a high-power and high-torque drilling machine is matched with a drilling inclinometer to monitor the drilling track in real time in the bedding long drilling construction process, the constructed bedding long drilling hole is ensured to completely cover a plurality of rock cross coal uncovering concentrated gas pre-drainage areas, the gas treatment range is accurately controlled, if the drilling hole does not completely cover the coal uncovering areas, the extraction drilling hole is re-drilled until the extraction range at the bottom of the drilling hole completely covers the coal uncovering areas;
and thirdly, after the upper section of the stone door I is drilled along the bedding layer by construction, the extraction reaches the standard (the requirement of 'temporary coal mine gas extraction standard reaching regulations' is met), the construction effect inspection holes are inspected when the distance between the tunneling working surfaces of the lower section of the stone door II and the lower section of the stone door III and the normal line of the coal seam to be uncovered is 7m, if the residual gas content and the residual gas pressure are smaller than the relevant regulations of 'preventing and controlling coal and gas outburst fine rules', and after no outburst danger is confirmed, the lower section of the stone door II and the lower section of the stone door III can be directly uncovered.
The invention has the beneficial effects that: compared with the prior art, by adopting the technical scheme of the invention, before a plurality of lower section rock gates II and lower section rock gates three-way expansion coal uncovering areas in the lower section are subjected to centralized gas pre-extraction at the coal uncovering position of the upper section rock gate I by using bedding long drilling holes, the coal uncovering areas of the lower section rock gates II and the lower section rock gates III are subjected to centralized gas pre-extraction, the outburst danger of the rock gates is eliminated, when the lower section rock gates II and the lower section rock gates III are constructed to the normal distance of 7m from a coal layer to be uncovered, the effect inspection is carried out, the outburst danger is confirmed to be met, and the coal uncovering can be directly carried. The gas treatment time is fully utilized when the gas treatment space of the upper section of the goaf is used for taking off the coal uncovering of the lower section of the goaf II and the lower section of the goaf III, and the problems that the coal uncovering time of the lower section of the goaf II and the lower section of the goaf III is long, the development footage is slow and the like are effectively solved.
The invention adopts bedding long drilling holes to extract and eliminate outburst in the two coal uncovering areas of the rock cross-section I and the coal uncovering area of the lower section II and the lower section III, the drilling construction and the gas extraction are not influenced by the excavation of the lower section rock cross, and the outburst prevention measures are only adopted once for the same coal uncovering areas of the lower section II and the lower section III, the gas control time is fully utilized when the upper section rock cross and the lower section rock cross and the coal uncovering area of the lower section II and the lower section rock cross are uncovered, the drilling extraction efficiency is effectively improved, the drilling extraction time is prolonged, when the lower section rock cross and the lower section rock cross are uncovered, the gas extraction work of the coal uncovering area is basically completed, the times of constructing and the coal uncovering drilling holes at the head of the working face are reduced, and the time for the lower section rock cross and the same coal uncovering areas are penetrated, the development efficiency is improved, and the safety production of the coal mine is ensured.
Drawings
FIG. 1 is a schematic structural view of the present invention;
FIG. 2 is a first plan view of the present invention;
FIG. 3 is a second plan view of the present invention;
in the figure: 1: an upper section of a stone door I; 2: a second lower section stone door; 3: a third lower section of a stone gate; 4: a coal seam; 5: a rock-gate drilling field at the upper section; 6: drilling along the layer length; 7: the outburst elimination range of the rock cross-cut secondary coal uncovering area of the lower section; 8: the outburst elimination range of the lower section of the rock cross three-uncovering coal area; 9: a working face is tunneled by the lower section stone door II; 10: and a lower section stone door three tunneling working face.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings.
Example 1: as shown in fig. 1 to 3, a cross-section coal uncovering accurate outburst elimination method for a rock cross, the method comprises the following steps:
firstly, when an upper section of a stone door I1 is in place or a coal seam 4 is uncovered, two lower section of stone doors II 2 which are being developed or are about to be developed are arranged on a lower section of the stone door I1, and a lower section of stone doors III 3 are used for uncovering the coal seam 4, drilling fields 5 are constructed on two sides of the coal uncovering position of the upper section of the stone door I1, a plurality of bedding long drill holes 6 are constructed (the number of bedding long drill holes is determined according to the distance between the layers of the upper section of stone doors and the lower section of stone doors and the roadway arrangement condition of the stone doors about to be uncovered), and the range of at least 12m outside the roadway outline of the two lower section of stone doors II 2 and the lower section of stone doors;
secondly, a directional drilling machine or a high-power and high-torque drilling machine is adopted to cooperate with a drilling inclinometer to monitor the drilling track in real time in the construction process of the bedding long drill hole 6, the condition that the constructed bedding long drill hole 6 completely covers a plurality of rock cross coal uncovering gas pre-drainage areas of the lower section is ensured, the gas control ranges 7 and 8 are accurately controlled, if the bedding long drill hole does not completely cover the coal uncovering areas, the bedding long drill hole 6 is re-drilled and extracted until the extraction range at the bottom of the bedding long drill hole 6 completely covers the coal uncovering areas;
and thirdly, after the upper section of the stone door 1 is subjected to construction bedding long drilling 6, after extraction reaches the standard (meeting the requirement of temporary stipulation for reaching the standard of coal mine gas extraction), a construction effect inspection hole is inspected when the distance between the driving working surface of the lower section of the stone door two 2 and the lower section of the stone door three 3 and the normal line of the coal layer 4 to be uncovered is 7m, and after no outburst danger is confirmed, coal uncovering operation can be directly performed on the lower section of the stone door two 2 and the lower section of the stone door three 3 if the residual gas content and the residual gas pressure are less than the relevant stipulation of the fine rule for preventing and controlling coal and gas outburst.
Embodiments of the invention are further described below with reference to the accompanying drawings:
as shown in fig. 1 and 2, the first upper cross drift 1 penetrates the coal seam 4, the second lower cross drift 2 and the third lower cross drift 3 are both in a tunneling state and do not expose the coal seam 4 penetrated by the first upper cross drift 1, a first drill site 5 of the upper cross drift is constructed on two sides (coal points) of a roadway at the coal uncovering position of the first upper cross drift 1, a long drill hole 6 is constructed along the inclined direction of the coal seam 4, and in the walking direction, a coal uncovering area (a coal uncovering area disappearing area 7 of the second lower cross drift and a coal uncovering area disappearing area 8 of the third lower cross drift) in a range of at least 12m outside the contour line of the roadway of the second lower cross drift 2 and the third lower cross drift 3 is controlled, so that gas pre-pumping in the coal uncovering area is realized. During the construction of the bedding long drill hole 6, a directional drilling machine or a high-power drilling machine is required to be matched with a drill hole inclinometer to ensure the control range of the drill hole (namely the outburst elimination range 7 of the lower section rock cross-cut two-uncovering area and the outburst elimination range 8 of the lower section rock cross-cut three-uncovering area).
As shown in fig. 3, after 5 gas extraction reaches the standard (meeting the requirement of temporary stipulation for meeting the standard of coal mine gas extraction) in the left and right upper section rock gate-drill sites, the lower section rock gate two 2 and the lower section rock gate three 3 are respectively tunneled to the position 7m away from the coal seam in the normal direction 4 to carry out regional outburst prevention measure effect inspection, and coal uncovering operation can be carried out after no outburst danger is confirmed, so that the number of times of head-on construction coal uncovering and drilling of the lower section rock gate two 2 and the lower section rock gate three 3 on the working face is reduced, the gas extraction time of the lower section rock gate two 2 and the lower section rock gate three 3 is saved, and the safe and rapid coal uncovering operation of the rock gates is ensured.
Before the coal uncovering is developed at the lower section of the second cross drift 2 and the lower section of the third cross drift 3, firstly, gas is pre-pumped in the coal uncovering area of the lower section of the second cross drift and the lower section of the third cross drift by adopting a bedding long drilling hole at the coal uncovering position of the upper section of the first cross drift, the outburst danger of the coal uncovering of the lower section of the second cross drift and the lower section of the third cross drift is eliminated, when the lower section of the second cross drift and the lower section of the third cross drift are constructed to be 7m away from the normal direction of a coal bed, effect inspection is carried out, no outburst danger is confirmed. The gas treatment time is fully utilized when the gas treatment space of the upper section of the goaf is used for taking off the coal uncovering of the lower section of the goaf II and the lower section of the goaf III, and the problems that the coal uncovering time of the lower section of the goaf II and the lower section of the goaf III is long, the development footage is slow and the like are effectively solved.
The invention adopts bedding long drilling holes to extract and eliminate outburst in the coal uncovering areas of the second and third lower sections of the rock gates in the two sides of the coal seam uncovered by the first upper section of the rock gate, the drilling construction and gas extraction are not influenced by the tunneling of the lower section of the rock gate, and the outburst prevention measures are only adopted once for the same coal seam uncovered by the second and third lower sections of the rock gate, the gas control time is fully utilized when the first gas control space of the first upper section of the rock gate is used for replacing the second and third coal uncovering areas of the second and third lower sections of the rock gate, the drilling extraction efficiency is effectively improved, the drilling extraction time is prolonged, when the second and third coal uncovering areas of the second and third lower sections of the rock gates are operated, the first coal gas extraction drilling hole of the first upper section of the rock gate completes the gas extraction work of the coal uncovering areas, the number of coal uncovering drilling holes in the construction head of the working face is reduced, and the time required for the second and third coal uncovering areas of the same coal seam on the second and third lower sections of the rock, the development efficiency is improved, and the safety production of the coal mine is ensured.
The invention relates to a precise outburst elimination technology for a cross section of a rock cross, which is suitable for pre-pumping gas in a rock cross coal uncovering area of a lower (upper) section in advance during the period that a plurality of rock cross sections are arranged in an upper (lower) section in sequence for jointly tunneling, extracting and drilling a coal layer uncovered by the rock cross sections of the upper (lower) section, improving the gas treatment efficiency during the period of rock cross coal uncovering, reducing the influence time of rock cross coal uncovering on roadway tunneling, and finally realizing the safe and rapid coal uncovering outburst elimination method for the rock cross sections of each section.
The present invention is not described in detail, but is known to those skilled in the art. Finally, the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all of them should be covered in the claims of the present invention.
Claims (1)
1. A rock cross-section coal uncovering accurate outburst elimination method is characterized by comprising the following steps: the method comprises the following steps:
firstly, when an upper section of a stone gate I (1) is in place or a coal bed (4) is uncovered, two lower section of stone gates II (2) which are being developed or are about to be developed are arranged on a lower section, and a lower section of stone gate III (3) is used for uncovering the coal bed (4), drilling sites are constructed on two sides of a coal uncovering position of the upper section of the stone gate I (1), a plurality of bedding long drill holes (6) are constructed, and the range of at least 12m outside the roadway contour line of the two lower section of stone gates II (2) and the lower section of stone gate III (3) of the lower section to be uncovered is controlled;
secondly, a directional drilling machine or a high-power and high-torque drilling machine is adopted to be matched with a drilling inclinometer to monitor the drilling track in real time in the construction process of the bedding long drill hole (6), so that the constructed bedding long drill hole (6) is ensured to completely cover the lower section rock cross coal uncovering concentrated gas pre-drainage area, and the gas control range is accurately controlled;
third, go up section rock cross one (1) through construction bedding length drilling (6), realize taking out and adopt up to standard after, at section rock cross two (2) down, construction effect inspection hole when section rock cross three (3) tunnelling working face and waiting to uncover coal seam (4) normal distance 7m examines, if residual gas content, residual gas pressure are less than the regulation requirement, confirm not have outstanding dangerous back, section rock cross two (2) down, section rock cross three (3) down can directly carry out the coal uncovering operation.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114165276A (en) * | 2021-12-08 | 2022-03-11 | 中煤科工集团重庆研究院有限公司 | Method for pre-pumping large-area coal seam gas in underground coal mine area |
| CN114263493A (en) * | 2021-12-28 | 2022-04-01 | 贵州盘江精煤股份有限公司 | Method for treating gas in lower section of coal face |
| CN116556966A (en) * | 2023-07-07 | 2023-08-08 | 山西凯嘉能源集团有限公司 | Roadway driving method for precisely eliminating coal roadway driving coal and gas outburst |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4978172A (en) * | 1989-10-26 | 1990-12-18 | Resource Enterprises, Inc. | Gob methane drainage system |
| WO1997049889A1 (en) * | 1996-06-25 | 1997-12-31 | Ian Gray | A system for directional control of drilling |
| CN103306677A (en) * | 2013-05-26 | 2013-09-18 | 贵州省矿山安全科学研究院 | Rapid rock cross-cut coal uncovering process and outburst prevention method |
| US20190145259A1 (en) * | 2017-03-20 | 2019-05-16 | China University Of Mining And Technology | Method for stepwise construction of preferential gas migration pathway at stope in coal seam |
| CN111101998A (en) * | 2020-01-19 | 2020-05-05 | 山西晋城无烟煤矿业集团有限责任公司 | Method for intercepting gas extracted from directional long drill hole |
| CN111396118A (en) * | 2020-03-19 | 2020-07-10 | 贵州盘江精煤股份有限公司 | Coal seam group rapid rock cross-cut coal uncovering outburst eliminating method |
-
2020
- 2020-11-20 CN CN202011311046.7A patent/CN112443351A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4978172A (en) * | 1989-10-26 | 1990-12-18 | Resource Enterprises, Inc. | Gob methane drainage system |
| WO1997049889A1 (en) * | 1996-06-25 | 1997-12-31 | Ian Gray | A system for directional control of drilling |
| CN103306677A (en) * | 2013-05-26 | 2013-09-18 | 贵州省矿山安全科学研究院 | Rapid rock cross-cut coal uncovering process and outburst prevention method |
| US20190145259A1 (en) * | 2017-03-20 | 2019-05-16 | China University Of Mining And Technology | Method for stepwise construction of preferential gas migration pathway at stope in coal seam |
| CN111101998A (en) * | 2020-01-19 | 2020-05-05 | 山西晋城无烟煤矿业集团有限责任公司 | Method for intercepting gas extracted from directional long drill hole |
| CN111396118A (en) * | 2020-03-19 | 2020-07-10 | 贵州盘江精煤股份有限公司 | Coal seam group rapid rock cross-cut coal uncovering outburst eliminating method |
Non-Patent Citations (3)
| Title |
|---|
| 安徽省地方志编纂委员会: "《安徽省志 煤炭工业志》", 30 April 1993 * |
| 许振温: "石门揭煤环形闭合底板巷区域防突措施初探", 《能源技术与管理》 * |
| 谷丽朋等: "我国煤矿瓦斯抽采技术的新进展及问题", 《能源技术与管理》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114165276A (en) * | 2021-12-08 | 2022-03-11 | 中煤科工集团重庆研究院有限公司 | Method for pre-pumping large-area coal seam gas in underground coal mine area |
| CN114263493A (en) * | 2021-12-28 | 2022-04-01 | 贵州盘江精煤股份有限公司 | Method for treating gas in lower section of coal face |
| CN116556966A (en) * | 2023-07-07 | 2023-08-08 | 山西凯嘉能源集团有限公司 | Roadway driving method for precisely eliminating coal roadway driving coal and gas outburst |
| CN116556966B (en) * | 2023-07-07 | 2023-09-19 | 山西凯嘉能源集团有限公司 | Roadway driving method for precisely eliminating coal roadway driving coal and gas outburst |
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Application publication date: 20210305 |