CN112412422A - Freezing fracturing cooperated coal seam hydraulic cavitation permeability increasing and pumping promoting method - Google Patents
Freezing fracturing cooperated coal seam hydraulic cavitation permeability increasing and pumping promoting method Download PDFInfo
- Publication number
- CN112412422A CN112412422A CN202011224443.0A CN202011224443A CN112412422A CN 112412422 A CN112412422 A CN 112412422A CN 202011224443 A CN202011224443 A CN 202011224443A CN 112412422 A CN112412422 A CN 112412422A
- Authority
- CN
- China
- Prior art keywords
- hole
- bag
- liquid injection
- extraction
- 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.)
- Withdrawn
Links
- 239000003245 coal Substances 0.000 title claims abstract description 110
- 238000000034 method Methods 0.000 title claims abstract description 47
- 230000001965 increasing effect Effects 0.000 title claims abstract description 33
- 238000005086 pumping Methods 0.000 title claims abstract description 32
- 230000035699 permeability Effects 0.000 title claims abstract description 31
- 230000001737 promoting effect Effects 0.000 title claims abstract description 26
- 238000007710 freezing Methods 0.000 title description 17
- 230000008014 freezing Effects 0.000 title description 17
- 239000007788 liquid Substances 0.000 claims abstract description 195
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 183
- 239000007924 injection Substances 0.000 claims abstract description 164
- 238000002347 injection Methods 0.000 claims abstract description 164
- 238000000605 extraction Methods 0.000 claims abstract description 157
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 91
- 238000007789 sealing Methods 0.000 claims abstract description 84
- 239000007789 gas Substances 0.000 claims abstract description 81
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 68
- 230000009471 action Effects 0.000 claims abstract description 29
- 230000000694 effects Effects 0.000 claims description 26
- 230000008569 process Effects 0.000 claims description 18
- 238000005553 drilling Methods 0.000 claims description 13
- 239000011148 porous material Substances 0.000 claims description 10
- 239000003566 sealing material Substances 0.000 claims description 6
- 238000000859 sublimation Methods 0.000 claims description 5
- 230000008022 sublimation Effects 0.000 claims description 5
- 238000005422 blasting Methods 0.000 claims description 3
- 230000003203 everyday effect Effects 0.000 claims description 3
- 238000012544 monitoring process Methods 0.000 claims description 3
- 230000002093 peripheral effect Effects 0.000 claims description 3
- 238000007599 discharging Methods 0.000 claims description 2
- 238000003860 storage Methods 0.000 claims description 2
- 230000002195 synergetic effect Effects 0.000 claims description 2
- 239000011435 rock Substances 0.000 abstract description 7
- 238000013461 design Methods 0.000 abstract description 4
- 238000009412 basement excavation Methods 0.000 abstract description 2
- 238000005516 engineering process Methods 0.000 description 11
- 239000010410 layer Substances 0.000 description 6
- 238000004080 punching Methods 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 238000005336 cracking Methods 0.000 description 3
- 238000005065 mining Methods 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 230000006378 damage Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 238000004880 explosion Methods 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 239000002689 soil Substances 0.000 description 2
- 238000005728 strengthening Methods 0.000 description 2
- 230000004075 alteration Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000002309 gasification Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- -1 polytetrafluoroethylene Polymers 0.000 description 1
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 1
- 239000004810 polytetrafluoroethylene Substances 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 239000011241 protective layer Substances 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000005641 tunneling Effects 0.000 description 1
Images
Classifications
-
- 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
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/25—Methods for stimulating production
- E21B43/26—Methods for stimulating production by forming crevices or fractures
-
- 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
-
- 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
- E21B33/138—Plastering the borehole wall; Injecting into the formation
-
- 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
- E21B36/00—Heating, cooling or insulating arrangements for boreholes or wells, e.g. for use in permafrost zones
- E21B36/001—Cooling arrangements
-
- 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
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/006—Production of coal-bed methane
-
- 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
- E21B7/18—Drilling by liquid or gas jets, with or without entrained pellets
Landscapes
- Engineering & Computer Science (AREA)
- Geology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- Physics & Mathematics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
Abstract
The method for promoting the permeability increase and the drainage of the coal seam by the aid of freeze fracturing and the hydraulic cavitation of the coal seam comprises the following steps of constructing crossheading drill holes on a working face crossheading, wherein the distance between every two adjacent drill holes is 7-10m, and the two adjacent drill holes are named as a liquid injection hole and a drainage hole respectively; installing an extraction pipe for hole sealing of the drilled hole, and connecting the extraction pipe with an underground extraction system to extract gas; injecting high-pressure water into the liquid injection hole; conveying the special hole packer into the extraction pipe in the liquid injection hole and sealing the hole; injecting liquid nitrogen into the liquid injection hole through a special hole packer to freeze coal around the liquid injection hole; under the action of the ground temperature, liquid nitrogen is slowly sublimated into nitrogen, and the nitrogen effectively replaces and displaces gas in the coal body; and connecting the extraction pipe in the liquid injection hole with an extraction system to perform gas extraction. The invention has scientific principle, ingenious design and tight hole sealing, can be widely applied to the works of rock cross-cut coal uncovering, fault crossing, excavation working face permeability increasing and pumping promoting and the like, has good permeability increasing and pumping promoting effects and wide application prospect.
Description
Technical Field
The invention belongs to the technical field of coal mine safety production, and particularly relates to a freezing fracturing synergistic coal seam hydraulic cavitation permeability-increasing pumping-promoting method.
Background
Most coal seams in China have the characteristics of 'three low and one high' (low permeability, low saturation, low reservoir pressure and high metamorphic degree). The low permeability of the coal seam causes difficulty in gas extraction, causes disorder of 'extraction-excavation-extraction' of a mine, forms a great potential safety production hazard, and is a hidden pen for gas accidents of a coal mine. Therefore, the study of scholars at home and abroad provides hydraulic cutting, protective layer mining, deep hole blasting, CO2And (3) technical measures for increasing permeability and promoting pumping of coal beds such as phase change fracturing. However, for various reasons, the anti-reflection effect of the technical measures commonly used at present needs to be further improved in terms of technology and economy.
The freezing and cracking phenomena are widely existed in nature, such as the phenomena of damage and destruction of buildings caused by freezing, more loose soil after freezing and the like are common. Inspired by these phenomena, scholars have conducted a great deal of research on the design of foundation engineering of frozen soil layers, and have obtained some beneficial research results. Later, in the oil and gas exploitation process, technicians apply the technology to the field of oil and gas exploitation to increase the permeability of an oil and gas layer, so that the purposes of increasing production and increasing efficiency are achieved, and a good effect is achieved. Coal is used as a special soft rock, and the purposes of fracturing coal bodies, increasing coal body hole-fractures and improving coal bed permeability can be realized by adopting an ultralow temperature freezing method; meanwhile, the coal body has poorer nitrogen adsorptivity than gas, and the ultralow-temperature liquid nitrogen after sublimation phase change expands hundreds of times in volume, so that the gas displacement and replacement in the coal body can be realized, and the gas extraction effect is further enhanced.
For a low-permeability coal bed, the coal body is soft, the air permeability is poor, and the extraction is difficult; in order to greatly increase the air permeability of the coal body and strengthen the gas extraction effect, the most effective method is to implement pressure relief measures such as hydraulic punching, hydraulic cave building and the like, and draw out a part of coal from the deep coal body through the hydraulic measures to fully relieve the pressure of the coal bed, thereby realizing the purpose of relieving the pressure and strengthening the gas extraction. The cross-layer drilling hydraulic punching technology is generally an anti-reflection pumping-promoting measure for drilling and hydraulic punching to an upper coal seam through a bottom plate rock tunnel, has the defects of high safety, long pre-pumping time and the like, but needs to construct the bottom plate rock tunnel in advance and then perform hydraulic punching, has high construction cost and low drilling utilization rate, and is not cost-effective in economy; in terms of technical level, the technical measures can be implemented only by the stratum horizon suitable for tunneling a bottom plate rock roadway; these all limit the popularization and application of the hydraulic punching technology.
Hydraulic cavitation is an emerging technology for increasing permeability and promoting pumping in recent years. For a coal seam without cross-layer drilling and hydraulic punching conditions, the hydraulic cave making technology is a technical measure for constructing cross-layer drilling in the coal seam and digging a cave in a coal body through hydraulic power so as to fully relieve pressure of the coal body. The specific technical principle is as follows: by carrying out hydraulic cave making after drilling along the coal bed, a certain amount of coal is artificially flushed out from the coal body to form a cave, and a sufficient space is provided for the expansion and deformation of the coal body; the coal body around the hole creeps under the action of strong ground stress, so that the coal body and gas are transported to the cave from a distance, the stress in the cave influence range is reduced, the pressure of the coal bed is fully relieved, cracks are increased, the gas permeability of the coal bed is greatly increased, the gas desorption and extraction are promoted, and the gas extraction effect is further improved. The hydraulic cave-making technology does not need to construct additional rock roadways and drill holes, greatly reduces the engineering quantity and effectively reduces the engineering cost.
However, the pressure relief of the area is difficult to realize only by means of hydraulic hole making technical measures, and the drainage blank zone is easy to cause when the pressure relief is uneven, so that hidden danger is brought to the prevention and control of mine gas disasters; and if large-area hydraulic hole making is to be implemented, a large amount of hole making engineering amount and hole making time are increased. Therefore, a new technical measure is urgently needed to be found, and the problems are effectively solved on the premise of ensuring the coal seam gas extraction effect and not increasing the hole making engineering quantity.
By combining the technologies, the coal body is subjected to freeze fracturing in the drill hole, the gas can be replaced and displaced to a far hydraulic cave-making drill hole influence area (low-pressure area) under the action of strong nitrogen partial pressure (high-pressure area), and the gas extraction effect can be enhanced under the action of strong gas pressure difference between the liquid injection hole and the cave-making extraction hole, so that the hydraulic cave-making engineering quantity can be greatly reduced, and the purposes of increasing permeability and promoting extraction are achieved. The freeze fracturing is cooperated with the coal seam hydraulic cave making technical measure, the coal seam gas extraction effect can be effectively improved, the cave making time is shortened, the method is very beneficial to solving the problem of the disorder of the pumping-digging-mining of the mine, and the method is a more advanced measure for increasing the permeability and promoting the pumping of the coal seam.
The freeze fracturing technology is generally applied in combination with a gas extraction technology. In the field application process of the freeze-induced cracking technology, liquid nitrogen is generally injected into a coal body through a drill hole, on one hand, the ultra-low temperature liquid nitrogen causes the coal body to be freeze-induced cracked through huge frost heaving force caused by liquid-solid phase change of a water body after the water injection of the coal body, the pores and cracks of a coal mine are effectively increased, and the effects of increasing reflection and promoting extraction are achieved, on the other hand, after the ultra-low temperature liquid nitrogen is heated, gasified and phase-changed into a gas state, the volume of the liquid nitrogen expands hundreds of times, so that huge nitrogen gas partial pressure can be formed, the effects of gas displacement and replacement are achieved for gas in the coal.
In the process of freeze fracturing coal body and gas extraction, hole sealing work is very important basic work; the quality of hole sealing directly influences the coal cracking degree and the gas extraction effect, and directly influences the economic benefit of the technology. The quality of hole sealing is mainly controlled by the performance of a special hole sealing device and a hole sealing process method; however, the existing hole sealing device and hole sealing method are designed under normal temperature conditions, and the problems of hole sealing material fracture, hole drilling air leakage, poor gas extraction effect and the like are easily caused under the ultralow temperature liquid nitrogen freezing and fracturing action, and the requirements of ultralow temperature liquid nitrogen injection and gas extraction work under normal temperature conditions are hardly met. Therefore, a special hole packer for increasing permeability and promoting pumping of the coal seam by combining freezing and fracturing, and a method for increasing permeability and promoting pumping are needed, which can simultaneously meet the requirements of hydraulic fracturing and ultralow-temperature liquid nitrogen injection, freezing and fracturing coal bodies and normal-temperature gas pumping, and achieve the purposes of increasing permeability and promoting pumping.
Disclosure of Invention
The invention aims to solve the defects in the prior art, provides a method for promoting pumping by combining freezing and fracturing with coal seam hydraulic cave forming permeability increasing, and aims to solve the problems that a conventional hole packer and a hole sealing method are poor in hole sealing effect and poor in pumping effect in the processes of freezing and fracturing coal bodies and gas pumping, and the like, so that the purposes of effectively improving the coal body freezing and fracturing degree, reducing the cave forming engineering quantity, improving the permeability increasing and pumping technical level and improving the coal seam gas pumping effect are achieved.
In order to solve the technical problems, the invention adopts the following technical scheme: the method for promoting the permeability increase and the pumping of the coal seam by the cooperation of freezing and fracturing comprises the following steps,
(1) operating a mechanical drilling machine to construct crossheading drill holes on a working face, wherein the drill holes are arranged in parallel, the distance between every two adjacent drill holes is 7-10m, and any two adjacent drill holes are named as a liquid injection hole and an extraction hole respectively;
(2) performing hydraulic hole making operation on the extraction hole, sealing the hole by adopting a conventional two-plugging one-injection process after the hydraulic hole making operation is finished, wherein the length of the sealed hole section of the hole is not less than 8 m; after the hole sealing material is solidified, connecting a first extraction pipe in an extraction hole with an underground extraction system of a coal mine to extract gas;
(3) connecting the outer end of a second extraction pipe in the liquid injection hole with a first grouting pump, starting the first grouting pump to perform high-pressure water injection on coal around the liquid injection hole, wherein the water pressure of the water injection is not less than 10 MPa; the coal around the liquid injection hole generates a large number of pores and a plurality of main cracks under the action of strong water pressure, and the water body enters the coal around the liquid injection hole and deep along the pores and the cracks;
(4) after the high-pressure water injection is finished, the first grouting pump is disconnected from the second extraction pipe in the liquid injection hole, accumulated water in the liquid injection hole is discharged, and the inner wall of the second extraction pipe in the position 8m away from the orifice is cleaned; at the moment, the coal around the liquid injection hole and in the depth is fully wetted;
(5) conveying the special hole packer into a second extraction pipe to a preset depth, and sealing the hole of the second extraction pipe;
(6) injecting liquid nitrogen into the liquid injection hole through a special hole packer to freeze coal around the liquid injection hole;
(7) after the nitrogen injection is finished, slowly sublimating liquid nitrogen into nitrogen under the action of the ground temperature, and continuously performing gas extraction operation on the nitrogen adjacent to the extraction hole of the liquid injection hole in the process; the volume expansion of the sublimed nitrogen is more than 500 times of that of injected liquid nitrogen, a high-pressure area is formed in the coal body around the liquid injection hole after the ultralow-temperature liquid nitrogen is gasified and sublimed, and a low-pressure area is formed by the creep and pressure relief action of the coal body in the peripheral area of the extraction hole after hydraulic hole making; a strong gas pressure difference is formed between the liquid injection hole and the extraction hole, the sublimated nitrogen can effectively replace and displace gas in the coal body, and the coal bed gas is extracted under the action of extraction negative pressure adjacent to the extraction hole, so that the gas extraction effect is enhanced;
(8) after the liquid nitrogen is completely sublimated for 48 hours, taking out the special hole packer from the second extraction pipe, and continuously reusing the special hole packer next time;
(9) connecting the outer end of the second extraction pipe in the liquid injection hole with an extraction system to perform gas extraction work so as to further enhance the gas extraction effect;
(10) and (3) in the gas extraction process, measuring the gas concentrations of the first extraction pipe and the second extraction pipe every day, separating the outer end of the second extraction pipe from the extraction system when detecting that the gas concentration in the first extraction pipe or the second extraction pipe is lower than 10%, and repeating the steps (4) - (9).
The special hole packer comprises a first bag, a second bag, a liquid injection pipe and a hole sealing pipe, wherein the liquid injection pipe and the hole sealing pipe are parallel to a second extraction pipe, the first bag and the second bag are fixedly arranged on the liquid injection pipe along the same central line, the second bag is positioned on the inner side of the first bag, the outlet end of the hole sealing pipe penetrates through the first bag and extends into the second bag, a through hole communicated with the inside of the first bag is formed in the hole sealing pipe, a closed cavity is formed between the first bag and the second bag in the second extraction pipe, a one-way valve is arranged on the second bag, the inlet of the one-way valve is communicated with the closed cavity, the outlet of the one-way valve is positioned on the inner side of the second bag, and a blasting valve is arranged between the first bag and the second bag on the hole sealing pipe; the joints of the liquid injection pipe, the hole sealing pipe and the one-way valve and the second bag are all connected in a sealing way, and the joints of the liquid injection pipe, the hole sealing pipe and the first bag are all connected in a sealing way.
The special hole packer further comprises a liquid nitrogen tank, a second grouting pump and a liquid injection pump, the second grouting pump is connected with the outer end of the hole sealing pipe through a grouting hose, the liquid nitrogen tank is arranged on the support in an inverted mode, the liquid nitrogen tank is connected with the outer end of the liquid injection pipe through a liquid injection hose, and the liquid injection pump is arranged on the liquid injection hose.
The outer end part of the liquid injection pipe is provided with a liquid injection valve, and the outer end part of the hole sealing pipe is provided with a hole sealing valve.
The second bag medial surface is equipped with temperature sensor, and the temperature sensor outside is equipped with waterproof bag, annotates the liquid pipe outer wall and has seted up the wire casing along length direction, and the wire casing is arranged to waterproof cable, and the inner and the temperature sensor of waterproof cable are connected, and the outer end of waterproof cable is connected with the temperature display screen that is located the drilling outside.
Fixing the first bag and the second bag on the liquid injection pipe, wherein the distance between the first bag and the second bag is not less than 2 m; connecting the hole sealing pipe with a grouting hose and a second grouting pump, opening a hole sealing valve, pumping clear water by the second grouting pump through the grouting hose and the hole sealing pipe to inject water into the first bag and the second bag, wherein the water injection pressure is not less than 2MPa, so that the outer edges of the first bag and the second bag are fully contacted with the inner wall of the second extraction pipe, and the purpose of sealing the second extraction pipe is achieved; continuously increasing the water injection pressure of the second grouting pump to open a blast valve between the first bag and the second bag on the hole sealing pipe, and allowing clear water to flow into a closed cavity formed between the first bag and the second bag in the second extraction pipe; the opening pressure of the one-way valve on the second bag is 2MPa, when the pressure in the closed cavity is greater than 2MPa, the one-way valve on the second bag is opened towards the inner side of the liquid injection hole, air in the closed cavity is discharged, clean water continuously flows into the closed cavity until the closed cavity is filled with water, and then the second grouting pump and the hole sealing valve are closed.
The specific process of the step (6) is that the ultra-low temperature liquid nitrogen tank is inverted on a bracket, a liquid injection pipe is connected with the liquid nitrogen tank through a liquid injection hose, and a liquid injection valve on the liquid injection pipe and a valve on the liquid nitrogen tank are opened in sequence; starting an injection pump to inject ultralow-temperature liquid nitrogen into the injection hole; when the ultralow-temperature liquid nitrogen is injected into the liquid storage tank in a sufficient amount, the liquid injection pump, the liquid injection valve on the liquid injection pipe and the valve on the liquid nitrogen tank are closed in sequence, and the liquid nitrogen tank is erected to ensure safety; in the nitrogen injection process, gas extraction operation is always carried out on the extraction hole adjacent to the liquid injection hole, so that escaped gas is guaranteed to be pumped away in time; under the action of ultralow-temperature liquid nitrogen, the first bag, the second bag and the water body in the closed cavity are quickly frozen, and under the action of the self-expansion force of the water body, the water body expands to tightly seal the second extraction pipe; meanwhile, moist coal in the injection holes is quickly frozen and frozen to crack, so that pores and cracks of the coal are increased, and a foundation is laid for increasing the permeability and promoting the pumping in the later period.
And (4) monitoring that the temperature in the liquid injection hole is higher than 0 ℃ through a temperature sensor during all the sublimation of the liquid nitrogen in the step (8), at the moment, the ice in the first bag, the second bag and the closed cavity is gradually melted, opening the hole-sealing valve after 48 hours, discharging the water in the first bag, the second bag and the closed cavity outwards, and taking out the special hole-sealing device from the second extraction pipe.
By adopting the technical scheme, the invention has the following technical effects:
1) the method utilizes the freezing and fracturing action of the water-containing coal body at the ultralow temperature and the liquid nitrogen frost heaving force to freeze and crack the coal body, can effectively improve the air permeability of the coal layer, greatly improve the gas extraction effect, achieve the effects of permeability increase and extraction promotion, and effectively solve the problem of disorder of extraction-excavation-extraction;
2) the method comprises the following steps of naturally heating frozen coal bodies by using the ground temperature, slowly sublimating ultralow-temperature liquid nitrogen in drill holes into gas, forming strong nitrogen partial pressure (high pressure region) on the coal bodies around a liquid injection hole, and forming lower gas pressure (low pressure region) on the peripheries of extraction drill holes; under the action of strong pressure difference between the liquid injection hole and the extraction hole, the sublimated nitrogen can effectively replace and displace gas in the coal body, and the coal bed gas is extracted under the action of extraction negative pressure of the adjacent extraction hole, so that the gas extraction effect is enhanced;
3) the freezing action of ultralow temperature liquid nitrogen is utilized, and water is used as a hole sealing material, so that the manufacturing cost is low, and the economy is good;
4) the large frost heaving force generated by natural expansion of the water under the action of ultralow temperature liquid nitrogen can be used for tightly sealing the drilled hole, so that the sealing effect is improved, and the coal body and underground water are not polluted;
5) a low-pressure area formed by the creep and pressure relief action of the coal body in the peripheral area of the drill hole after hydraulic hole making and a high-pressure area formed around the liquid injection hole after ultralow-temperature liquid nitrogen gasification and sublimation form a strong gas pressure difference between the liquid injection hole and the extraction hole, so that the method is favorable for enhancing the permeability increase and extraction promotion of the coal body, greatly reduces the hydraulic hole making engineering quantity, realizes the balance of extraction-excavation-extraction of a mine and ensures the safety of the mine.
6) The extraction pipe adopts a conventional mining PVE pipe; the hole sealing pipe and the liquid injection pipe both adopt polytetrafluoroethylene pipes, and the pipe has the characteristics of low temperature resistance (5% of elongation can be kept even if the temperature is reduced to-196 ℃), corrosion resistance, static resistance, flame retardance, hydrophobicity, non-adhesiveness and the like, can be applied to a special hole sealing device, and ensures the air tightness.
7) The special hole packer adopts the design of matching a double-bag with a one-way valve and an explosion valve, and can smoothly discharge water in the bag and between the two bags; the water body hole sealing section is arranged in the extraction pipe, the inner wall of the extraction pipe is smooth and has small deformation, and tight hole sealing of a drilled hole can be effectively ensured; the measures ensure that the hole sealing device can be repeatedly used, and reduce the cost of hole sealing materials.
8) After the liquid injection hole is used for injecting liquid and freezing, the liquid injection hole can be continuously used as a gas extraction hole, and the purpose of dual purposes in one hole is achieved.
9) And monitoring the temperature in the liquid injection hole by using a temperature sensor, starting timing when the display screen displays that the temperature is higher than 0 ℃ after liquid nitrogen is injected, and disassembling the special hole packer after 48 hours, so that the water body hole packer section can be ensured to be completely melted.
In conclusion, the invention has scientific principle, ingenious design, tight hole sealing, safety and reliability, can be widely applied to the works of rock cross-cut coal uncovering, fault crossing, excavation working face permeability increasing and pumping promoting and the like, has good permeability increasing and pumping promoting effects and wide application prospect.
Drawings
FIG. 1 is a schematic structural diagram of a special hole packer in operation;
FIG. 2 is a schematic diagram of the placement of the injection holes and extraction holes in the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.
As shown in fig. 1 and fig. 2, the freeze fracturing and coal seam hydraulic cavitation permeability-increasing pumping-promoting method provided by the invention comprises the following steps: (1) operating a mechanical drilling machine to construct crossheading drill holes on a coal body 2 at a working face crossheading 1, wherein the drill holes are arranged in parallel, the distance between every two adjacent drill holes is 7-10m, and any two adjacent drill holes are respectively named as a liquid injection hole 3 and an extraction hole 4;
(2) hydraulic hole making is carried out on the extraction hole 4, after hydraulic hole making construction is finished, conventional hole sealing is carried out on the drill hole through a two-plugging one-injection process, and the length of the sealing section of the drill hole is not less than 8 m; after the hole sealing material is solidified, connecting a first extraction pipe in the extraction hole 4 with an extraction system 5 (an extraction pipeline) under the coal mine to extract gas;
(3) connecting the outer end of a second extraction pipe 6 in the liquid injection hole 3 with a first grouting pump, starting the first grouting pump to perform high-pressure water injection on the coal body 2 around the liquid injection hole 3, wherein the water pressure of the water injection is not less than 10 MPa; the coal body 2 around the liquid injection hole 3 generates a large number of pores and a plurality of main cracks under the action of strong water pressure, and the water body enters the periphery of the liquid injection hole 3 and the depth of the coal body 2 along the pores and the cracks;
(4) after the high-pressure water injection is finished, the first grouting pump is disconnected from the second extraction pipe 6 in the liquid injection hole 3, accumulated water in the liquid injection hole 3 is discharged, and the inner wall of the second extraction pipe 6, which is 8m away from the orifice, is cleaned; at this time, the coal body 2 around the liquid injection hole 3 and deep is fully wet;
(5) the special hole packer is sent into the second extraction pipe 6 to a preset depth, and hole sealing is carried out on the second extraction pipe 6;
(6) liquid nitrogen is injected into the liquid injection hole 3 through a special hole packer to freeze the coal body 2 around the liquid injection hole 3;
(7) after the nitrogen injection is finished, slowly sublimating liquid nitrogen into nitrogen under the action of the ground temperature, and continuously performing gas extraction operation on the nitrogen adjacent to the extraction hole 4 of the liquid injection hole 3 in the process; the volume expansion of the sublimed nitrogen is more than 500 times of that of the injected liquid nitrogen, strong nitrogen partial pressure, namely a high-pressure area, is formed around the injection hole 3 in the coal body 2, and lower gas pressure, namely a low-pressure area, is formed around the extraction hole 4; under the action of strong pressure difference between the liquid injection hole and the extraction hole, the sublimated nitrogen can effectively replace and displace gas in the coal body 2, and under the action of extraction negative pressure of the adjacent extraction hole 4, coal bed gas is extracted, so that the gas extraction effect is enhanced;
(8) after the liquid nitrogen is completely sublimated for 48 hours, taking out the special hole packer from the second extraction pipe 6, and continuously reusing the special hole packer next time;
(9) connecting the outer end of a second extraction pipe 6 in the liquid injection hole 3 with an extraction system 5 to perform gas extraction work, and further strengthening the gas extraction effect;
(10) and (3) in the gas extraction process, measuring the gas concentrations of the first extraction pipe and the second extraction pipe 6 every day, separating the outer end of the second extraction pipe 6 from the extraction system 5 when the gas concentration in the first extraction pipe or the second extraction pipe 6 is detected to be lower than 10%, and repeating the steps (4) - (9).
The special hole packer comprises a first bag 7, a second bag 8, an injection pipe 9 and a hole sealing pipe 10, wherein the injection pipe 9 and the hole sealing pipe 10 are parallel to a second extraction pipe 6, the first bag 7 and the second bag 8 are fixedly arranged on the injection pipe 9 along the same central line, the second bag 8 is positioned on the inner side of the first bag 7, the outlet end of the hole sealing pipe 10 penetrates through the first bag 7 to extend into the second bag 8, a through hole communicated with the inside of the first bag 7 is formed in the hole sealing pipe 10, a closed cavity 11 is formed between the first bag 7 and the second bag 8 in the second extraction pipe 6, a one-way valve 12 is arranged on the second bag 8, the inlet of the one-way valve 12 is communicated with the closed cavity 11, the outlet of the one-way valve 12 is positioned on the inner side of the second bag 8, and an explosion valve 13 is arranged between the first bag 7 and the second bag 8 on the hole sealing pipe 10; the joints of the liquid injection pipe 9, the hole sealing pipe 10, the one-way valve 12 and the second bag 8 are all connected in a sealing way, and the joints of the liquid injection pipe 9, the hole sealing pipe 10 and the first bag 7 are all connected in a sealing way.
The special hole packer further comprises a liquid nitrogen tank 14, a second grouting pump 15 and a liquid injection pump 16, wherein the second grouting pump 15 is connected with the outer end of the hole sealing pipe 10 through a grouting hose 17, the liquid nitrogen tank 14 is arranged on the support 18 in an inverted mode, the liquid nitrogen tank 14 is connected with the outer end of the liquid injection pipe 9 through a liquid injection hose 19, and the liquid injection pump 16 is arranged on the liquid injection hose 19.
The outer end part of the liquid injection pipe 9 is provided with a liquid injection valve 20, and the outer end part of the hole sealing pipe 10 is provided with a hole sealing valve 21.
8 medial surfaces of second bag are equipped with temperature sensor 22, and temperature sensor 22 outside is equipped with the waterproof bag, annotates liquid pipe 9 outer wall and has seted up the wire casing along length direction, has arranged waterproof cable 23 in the wire casing, and the inner and the temperature sensor 22 of waterproof cable 23 are connected, and the outer end of waterproof cable 23 is connected with the temperature display screen 24 that is located the drilling outside.
The specific process of the step (5) is that the first bag 7 and the second bag 8 are fixed on the liquid injection pipe 9, and the distance between the first bag 7 and the second bag 8 is not less than 2 m; connecting the hole sealing pipe 10 with the grouting hose 17 and the second grouting pump 15, opening a hole opening valve 21, pumping clear water by the second grouting pump 15 through the grouting hose 17 and the hole sealing pipe 10 to inject water into the first bag 7 and the second bag 8, wherein the water injection pressure is not less than 2MPa, so that the outer edges of the first bag 7 and the second bag 8 are fully contacted with the inner wall of the second extraction pipe 6, and the purpose of sealing the second extraction pipe 6 is achieved; continuously increasing the water injection pressure of a second grouting pump 15 to open a blast valve 13 on the hole sealing pipe 10 between the first bag 7 and the second bag 8, and allowing clear water to flow into a closed cavity 11 formed between the first bag 7 and the second bag 8 in the second extraction pipe 6; the opening pressure of the one-way valve 12 on the second bag 8 is 2MPa, when the pressure in the closed cavity 11 is greater than 2MPa, the one-way valve 12 on the second bag 8 is opened towards the inner side of the liquid injection hole 3, air in the closed cavity 11 is discharged, clean water is enabled to continuously flow into the closed cavity 11 until the closed cavity 11 is filled with water (the time required for filling water can be calculated according to the volumes of the first bag 7, the second bag 8 and the closed cavity 11 and the water injection speed of the second grouting pump 15, the time required for filling water can be prolonged by 1-2 minutes after the calculated time for ensuring that the closed cavity 11 is filled with water), and then the second grouting pump 15 and the hole sealing valve 21 are closed.
The specific process of the step (6) is that the ultra-low temperature liquid nitrogen tank 14 is inverted on the bracket 18, the liquid injection pipe 9 is connected with the liquid nitrogen tank 14 through the liquid injection hose 19, and the liquid injection valve 20 on the liquid injection pipe 9 and the valve on the liquid nitrogen tank 14 are opened in sequence; starting an injection pump 16 to inject ultralow-temperature liquid nitrogen into the injection hole 3; when the ultralow-temperature liquid nitrogen is injected into a sufficient amount, the liquid injection pump 16, the liquid injection valve 20 on the liquid injection pipe 9 and the valve on the liquid nitrogen tank 14 are closed in sequence, and the liquid nitrogen tank 14 is erected to ensure safety; in the nitrogen injection process, the gas extraction operation is always carried out on the extraction hole 4 adjacent to the liquid injection hole 3, so that the escaped gas is ensured to be extracted in time; under the action of ultralow temperature liquid nitrogen, the water in the first bag 7, the second bag 8 and the closed cavity 11 is quickly frozen, and under the action of the self expansion force of the water, the water expands to tightly seal the second extraction pipe 6; meanwhile, the wet coal body 2 in the liquid injection hole 3 is rapidly frozen and frozen to crack, so that pores and cracks of the coal body 2 are increased, and a foundation is laid for increasing the later-period permeability and pumping.
In the step (8), when the temperature in the liquid injection hole 3 is monitored to be higher than 0 ℃ through the temperature sensor 22 during all the liquid nitrogen sublimation, ice in the first bag 7, the second bag 8 and the closed cavity 11 is gradually melted, after 48 hours, the hole-opening valve 21 is opened, water in the first bag 7, the second bag 8 and the closed cavity 11 is discharged outwards, and then the special hole sealer is taken out of the second extraction pipe 6.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (8)
1. The freeze fracturing and coal seam hydraulic cavitation permeability-increasing and pumping-promoting method is characterized by comprising the following steps: comprises the following steps of (a) carrying out,
(1) operating a mechanical drilling machine to construct crossheading drill holes on a working face, wherein the drill holes are arranged in parallel, the distance between every two adjacent drill holes is 7-10m, and any two adjacent drill holes are named as a liquid injection hole and an extraction hole respectively;
(2) performing hydraulic hole making operation on the extraction hole, sealing the hole by adopting a conventional two-plugging one-injection process after the hydraulic hole making operation is finished, wherein the length of the sealed hole section of the hole is not less than 8 m; after the hole sealing material is solidified, connecting a first extraction pipe in an extraction hole with an underground extraction system of a coal mine to extract gas;
(3) connecting the outer end of a second extraction pipe in the liquid injection hole with a first grouting pump, starting the first grouting pump to perform high-pressure water injection on coal around the liquid injection hole, wherein the water pressure of the water injection is not less than 10 MPa; the coal around the liquid injection hole generates a large number of pores and a plurality of main cracks under the action of strong water pressure, and the water body enters the coal around the liquid injection hole and deep along the pores and the cracks;
(4) after the high-pressure water injection is finished, the first grouting pump is disconnected from the second extraction pipe in the liquid injection hole, accumulated water in the liquid injection hole is discharged, and the inner wall of the second extraction pipe in the position 8m away from the orifice is cleaned; at the moment, the coal around the liquid injection hole and in the depth is fully wetted;
(5) conveying the special hole packer into a second extraction pipe to a preset depth, and sealing the hole of the second extraction pipe;
(6) injecting liquid nitrogen into the liquid injection hole through a special hole packer to freeze coal around the liquid injection hole;
(7) after the nitrogen injection is finished, slowly sublimating liquid nitrogen into nitrogen under the action of the ground temperature, and continuously performing gas extraction operation on the nitrogen adjacent to the extraction hole of the liquid injection hole in the process; the volume expansion of the sublimed nitrogen is more than 500 times of that of injected liquid nitrogen, a high-pressure area is formed in the coal body around the liquid injection hole after the ultralow-temperature liquid nitrogen is gasified and sublimed, and a low-pressure area is formed by the creep and pressure relief action of the coal body in the peripheral area of the extraction hole after hydraulic hole making; a strong gas pressure difference is formed between the liquid injection hole and the extraction hole, the sublimated nitrogen can effectively replace and displace gas in the coal body, and the coal bed gas is extracted under the action of extraction negative pressure adjacent to the extraction hole, so that the gas extraction effect is enhanced;
(8) after the liquid nitrogen is completely sublimated for 48 hours, taking out the special hole packer from the second extraction pipe, and continuously reusing the special hole packer next time;
(9) connecting the outer end of the second extraction pipe in the liquid injection hole with an extraction system to perform gas extraction work so as to further enhance the gas extraction effect;
(10) and (3) in the gas extraction process, measuring the gas concentrations of the first extraction pipe and the second extraction pipe every day, separating the outer end of the second extraction pipe from the extraction system when detecting that the gas concentration in the first extraction pipe or the second extraction pipe is lower than 10%, and repeating the steps (4) - (9).
2. The method for promoting the hydraulic cave permeability-increasing and pumping of the coalbed by the aid of the frozen fracturing synergies according to claim 1, is characterized in that: the special hole packer comprises a first bag, a second bag, a liquid injection pipe and a hole sealing pipe, wherein the liquid injection pipe and the hole sealing pipe are parallel to a second extraction pipe, the first bag and the second bag are fixedly arranged on the liquid injection pipe along the same central line, the second bag is positioned on the inner side of the first bag, the outlet end of the hole sealing pipe penetrates through the first bag and extends into the second bag, a through hole communicated with the inside of the first bag is formed in the hole sealing pipe, a closed cavity is formed between the first bag and the second bag in the second extraction pipe, a one-way valve is arranged on the second bag, the inlet of the one-way valve is communicated with the closed cavity, the outlet of the one-way valve is positioned on the inner side of the second bag, and a blasting valve is arranged between the first bag and the second bag on the hole sealing pipe; the joints of the liquid injection pipe, the hole sealing pipe and the one-way valve and the second bag are all connected in a sealing way, and the joints of the liquid injection pipe, the hole sealing pipe and the first bag are all connected in a sealing way.
3. The method for promoting the hydraulic cave permeability-increasing and pumping of the coalbed by the aid of the frozen fracturing synergies according to claim 1, is characterized in that: the special hole packer further comprises a liquid nitrogen tank, a second grouting pump and a liquid injection pump, the second grouting pump is connected with the outer end of the hole sealing pipe through a grouting hose, the liquid nitrogen tank is arranged on the support in an inverted mode, the liquid nitrogen tank is connected with the outer end of the liquid injection pipe through a liquid injection hose, and the liquid injection pump is arranged on the liquid injection hose.
4. The method for promoting the permeability increase and the drainage of the freeze fracturing cooperated coal seam hydraulic cavitation according to claim 2 or 3, is characterized in that: the outer end part of the liquid injection pipe is provided with a liquid injection valve, and the outer end part of the hole sealing pipe is provided with a hole sealing valve.
5. The method for promoting the hydraulic cave permeability-increasing and pumping of the freeze fracturing synergetic coal seam according to claim 4, wherein the method comprises the following steps: the second bag medial surface is equipped with temperature sensor, and the temperature sensor outside is equipped with waterproof bag, annotates the liquid pipe outer wall and has seted up the wire casing along length direction, and the wire casing is arranged to waterproof cable, and the inner and the temperature sensor of waterproof cable are connected, and the outer end of waterproof cable is connected with the temperature display screen that is located the drilling outside.
6. The method for promoting the hydraulic cave permeability-increasing and pumping of the coalbed by the aid of the frozen fracturing and the coal seam according to claim 5, wherein the method comprises the following steps: fixing the first bag and the second bag on the liquid injection pipe, wherein the distance between the first bag and the second bag is not less than 2 m; connecting the hole sealing pipe with a grouting hose and a second grouting pump, opening a hole sealing valve, pumping clear water by the second grouting pump through the grouting hose and the hole sealing pipe to inject water into the first bag and the second bag, wherein the water injection pressure is not less than 2MPa, so that the outer edges of the first bag and the second bag are fully contacted with the inner wall of the second extraction pipe, and the purpose of sealing the second extraction pipe is achieved; continuously increasing the water injection pressure of the second grouting pump to open a blast valve between the first bag and the second bag on the hole sealing pipe, and allowing clear water to flow into a closed cavity formed between the first bag and the second bag in the second extraction pipe; the opening pressure of the one-way valve on the second bag is 2MPa, when the pressure in the closed cavity is greater than 2MPa, the one-way valve on the second bag is opened towards the inner side of the liquid injection hole, air in the closed cavity is discharged, clean water continuously flows into the closed cavity until the closed cavity is filled with water, and then the second grouting pump and the hole sealing valve are closed.
7. The method for promoting the hydraulic cave permeability-increasing and pumping of the coalbed by the aid of the frozen fracturing and the coal seam according to claim 6, wherein the method comprises the following steps: the specific process of the step (6) is that the ultra-low temperature liquid nitrogen tank is inverted on a bracket, a liquid injection pipe is connected with the liquid nitrogen tank through a liquid injection hose, and a liquid injection valve on the liquid injection pipe and a valve on the liquid nitrogen tank are opened in sequence; starting an injection pump to inject ultralow-temperature liquid nitrogen into the injection hole; when the ultralow-temperature liquid nitrogen is injected into the liquid storage tank in a sufficient amount, the liquid injection pump, the liquid injection valve on the liquid injection pipe and the valve on the liquid nitrogen tank are closed in sequence, and the liquid nitrogen tank is erected to ensure safety; in the nitrogen injection process, gas extraction operation is always carried out on the extraction hole adjacent to the liquid injection hole, so that escaped gas is guaranteed to be pumped away in time; under the action of ultralow-temperature liquid nitrogen, the first bag, the second bag and the water body in the closed cavity are quickly frozen, and under the action of the self-expansion force of the water body, the water body expands to tightly seal the second extraction pipe; meanwhile, moist coal in the injection holes is quickly frozen and frozen to crack, so that pores and cracks of the coal are increased, and a foundation is laid for increasing the permeability and promoting the pumping in the later period.
8. The method for promoting the hydraulic cave permeability-increasing and pumping of the coalbed by the aid of the frozen fracturing synergies according to claim 7, is characterized in that: and (4) monitoring that the temperature in the liquid injection hole is higher than 0 ℃ through a temperature sensor during all the sublimation of the liquid nitrogen in the step (8), at the moment, the ice in the first bag, the second bag and the closed cavity is gradually melted, opening the hole-sealing valve after 48 hours, discharging the water in the first bag, the second bag and the closed cavity outwards, and taking out the special hole-sealing device from the second extraction pipe.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011224443.0A CN112412422A (en) | 2020-11-05 | 2020-11-05 | Freezing fracturing cooperated coal seam hydraulic cavitation permeability increasing and pumping promoting method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011224443.0A CN112412422A (en) | 2020-11-05 | 2020-11-05 | Freezing fracturing cooperated coal seam hydraulic cavitation permeability increasing and pumping promoting method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112412422A true CN112412422A (en) | 2021-02-26 |
Family
ID=74828640
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011224443.0A Withdrawn CN112412422A (en) | 2020-11-05 | 2020-11-05 | Freezing fracturing cooperated coal seam hydraulic cavitation permeability increasing and pumping promoting method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112412422A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113202446A (en) * | 2021-06-25 | 2021-08-03 | 河南理工大学 | Reusable hole packer for coal mine underground gas extraction cross-layer drilling and operation method thereof |
| CN114370256A (en) * | 2022-01-17 | 2022-04-19 | 西安科技大学 | System and method for increasing permeability and gas displacement of carbon dioxide hot steam freeze-thaw coal seam |
| CN115163021A (en) * | 2022-07-13 | 2022-10-11 | 中国矿业大学 | Water injection nitrogen injection gas extraction and extraction gas hole sealing device and drill hole arrangement method |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2067181C1 (en) * | 1992-01-16 | 1996-09-27 | Научно-производственная фьючерская фирма "Геоэнергия" | Method for decrease of gas dynamic activity of outburst-prone seams |
| US20050082058A1 (en) * | 2003-09-23 | 2005-04-21 | Bustin Robert M. | Method for enhancing methane production from coal seams |
| CN104563990A (en) * | 2015-01-06 | 2015-04-29 | 中国矿业大学 | Drilling and blanking integrated and heat injection coordinated enhancing method for extracting coal seam gas |
| CN105134284A (en) * | 2015-08-03 | 2015-12-09 | 中国矿业大学 | Gas extraction method based on horizontal orientation boring liquid nitrogen cycle freeze-thaw anti-reflection |
| CN106703871A (en) * | 2017-02-06 | 2017-05-24 | 华北科技学院 | Method of using high-pressure water injection to prevent and treat gas coal dust |
| CN207131371U (en) * | 2017-09-14 | 2018-03-23 | 河南能源化工集团研究院有限公司 | Coal mine gas drainage holes controllable capsule bag type hole-sealing device with pressure |
| CN108678721A (en) * | 2018-06-15 | 2018-10-19 | 吕梁学院 | Packaged type hydraulic fracturing and injection hole sealing integrated apparatus and its construction method |
| CN208168927U (en) * | 2018-04-27 | 2018-11-30 | 河南理工大学 | Hypotonic coal seam electric detonation shake and microwave-assisted frozen-thawed permeability improvement device |
| CN110953016A (en) * | 2019-12-27 | 2020-04-03 | 煤炭科学技术研究院有限公司 | Method for preventing and controlling coal and gas outburst through pressure relief and energy dissipation and freezing solidification cooperation |
-
2020
- 2020-11-05 CN CN202011224443.0A patent/CN112412422A/en not_active Withdrawn
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2067181C1 (en) * | 1992-01-16 | 1996-09-27 | Научно-производственная фьючерская фирма "Геоэнергия" | Method for decrease of gas dynamic activity of outburst-prone seams |
| US20050082058A1 (en) * | 2003-09-23 | 2005-04-21 | Bustin Robert M. | Method for enhancing methane production from coal seams |
| CN104563990A (en) * | 2015-01-06 | 2015-04-29 | 中国矿业大学 | Drilling and blanking integrated and heat injection coordinated enhancing method for extracting coal seam gas |
| CN105134284A (en) * | 2015-08-03 | 2015-12-09 | 中国矿业大学 | Gas extraction method based on horizontal orientation boring liquid nitrogen cycle freeze-thaw anti-reflection |
| CN106703871A (en) * | 2017-02-06 | 2017-05-24 | 华北科技学院 | Method of using high-pressure water injection to prevent and treat gas coal dust |
| CN207131371U (en) * | 2017-09-14 | 2018-03-23 | 河南能源化工集团研究院有限公司 | Coal mine gas drainage holes controllable capsule bag type hole-sealing device with pressure |
| CN208168927U (en) * | 2018-04-27 | 2018-11-30 | 河南理工大学 | Hypotonic coal seam electric detonation shake and microwave-assisted frozen-thawed permeability improvement device |
| CN108678721A (en) * | 2018-06-15 | 2018-10-19 | 吕梁学院 | Packaged type hydraulic fracturing and injection hole sealing integrated apparatus and its construction method |
| CN110953016A (en) * | 2019-12-27 | 2020-04-03 | 煤炭科学技术研究院有限公司 | Method for preventing and controlling coal and gas outburst through pressure relief and energy dissipation and freezing solidification cooperation |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113202446A (en) * | 2021-06-25 | 2021-08-03 | 河南理工大学 | Reusable hole packer for coal mine underground gas extraction cross-layer drilling and operation method thereof |
| CN114370256A (en) * | 2022-01-17 | 2022-04-19 | 西安科技大学 | System and method for increasing permeability and gas displacement of carbon dioxide hot steam freeze-thaw coal seam |
| CN115163021A (en) * | 2022-07-13 | 2022-10-11 | 中国矿业大学 | Water injection nitrogen injection gas extraction and extraction gas hole sealing device and drill hole arrangement method |
| CN115163021B (en) * | 2022-07-13 | 2023-11-03 | 中国矿业大学 | Water injection and nitrogen injection gas extraction hole sealing device and drilling arrangement method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10577891B2 (en) | Using horizontal directional drilling and liquid nitrogen cyclic freeze-thaw process to improve permeability in gas drainage | |
| CN110145233B (en) | Rock burst coal seam drilling-cutting-pressing-pumping-injecting multi-disaster cooperative prevention and control method | |
| CN112412422A (en) | Freezing fracturing cooperated coal seam hydraulic cavitation permeability increasing and pumping promoting method | |
| CN112412418A (en) | Freezing fracturing synergistic hydraulic punching permeability-increasing pumping-promoting method for low-permeability coal seam | |
| CN102852546B (en) | Method for pre-pumping coal roadway stripe gas of single soft protruded coal seam of unexploited area | |
| CN103291325B (en) | The preventing control method of Coal-mining Above Confined-water floor strata gushing water | |
| WO2016019825A1 (en) | Enhanced phase-change fracking gas extraction method for low-permeability coal bed | |
| CN106703871A (en) | Method of using high-pressure water injection to prevent and treat gas coal dust | |
| CN112412415B (en) | Hydraulic punching, freezing fracturing and heat injection stimulation synergistic permeability-increasing pumping-promoting method | |
| CN101105138A (en) | Method for suppressing coal and gas outburst | |
| CN109025940B (en) | CO for tight oil reservoir2Fracturing oil displacement integrated oil extraction method | |
| CN104696006B (en) | Ground drilling penetrates the method for abandoned coal pillar extraction multilamellar old dead zone remnants coal bed gas | |
| WO2019029178A1 (en) | New gas control technology for ground pressure-relief borehole in abandoned coal mine | |
| CN112412417B (en) | Method for promoting pumping of coal seam by combining hydraulic cave building with drilling, heat injection, permeability increase | |
| CN107100625A (en) | High water retaining mining method is led in overlying strata water filling filling reduction | |
| CN112412420A (en) | Hydraulic cavitation, freezing fracturing and heat injection stimulation synergistic anti-reflection pumping-promoting method | |
| CN105804786A (en) | Method for layer penetrating, drilling, pressing punching and permeability improving of soft coal seam floor | |
| CN113653531B (en) | Method for dredging low-permeability roof water | |
| CN114370256A (en) | System and method for increasing permeability and gas displacement of carbon dioxide hot steam freeze-thaw coal seam | |
| CN105927192A (en) | Method for exploiting coal bed methane in collapse old goafs and lower coal beds in combined manner | |
| CN112412419A (en) | Method for increasing permeability and promoting pumping of frozen fractured coal | |
| CN102797448B (en) | Retreating sectional type hydraulic cracking method | |
| CN107558950A (en) | Orientation blocking method for the closing of oil shale underground in situ production zone | |
| CN105781606A (en) | Method for sealing large-dip-angle downward coal-seam-penetrating gas extraction-drainage drill hole | |
| CN114810197B (en) | Gas permeability increasing method for coal roadway driving face dynamic and static combined action |
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 | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20210226 |
|
| WW01 | Invention patent application withdrawn after publication |