CN116146160A - Liquid CO 2 Alkaline water fracturing permeability-increasing gas extraction and coal seam water injection method - Google Patents
Liquid CO 2 Alkaline water fracturing permeability-increasing gas extraction and coal seam water injection method Download PDFInfo
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- CN116146160A CN116146160A CN202211094155.7A CN202211094155A CN116146160A CN 116146160 A CN116146160 A CN 116146160A CN 202211094155 A CN202211094155 A CN 202211094155A CN 116146160 A CN116146160 A CN 116146160A
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- 239000003245 coal Substances 0.000 title claims abstract description 86
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 64
- 238000000605 extraction Methods 0.000 title claims abstract description 63
- 239000007788 liquid Substances 0.000 title claims abstract description 40
- 238000002347 injection Methods 0.000 title claims abstract description 38
- 239000007924 injection Substances 0.000 title claims abstract description 38
- 238000000034 method Methods 0.000 title claims abstract description 26
- 238000005553 drilling Methods 0.000 claims abstract description 50
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims abstract description 42
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 38
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims abstract description 26
- 229910002092 carbon dioxide Inorganic materials 0.000 claims abstract description 21
- 239000001569 carbon dioxide Substances 0.000 claims abstract description 20
- 229910052742 iron Inorganic materials 0.000 claims abstract description 19
- 230000000694 effects Effects 0.000 claims abstract description 13
- 230000008569 process Effects 0.000 claims abstract description 9
- 238000010276 construction Methods 0.000 claims abstract description 8
- 238000006073 displacement reaction Methods 0.000 claims abstract description 8
- 238000007789 sealing Methods 0.000 claims abstract description 8
- 230000008016 vaporization Effects 0.000 claims abstract description 7
- 238000009834 vaporization Methods 0.000 claims abstract description 6
- 238000006386 neutralization reaction Methods 0.000 claims abstract description 5
- 230000001681 protective effect Effects 0.000 claims description 18
- 238000001179 sorption measurement Methods 0.000 claims description 10
- 230000009471 action Effects 0.000 claims description 6
- 239000000463 material Substances 0.000 claims description 5
- 238000005065 mining Methods 0.000 claims description 3
- FGUUSXIOTUKUDN-IBGZPJMESA-N C1(=CC=CC=C1)N1C2=C(NC([C@H](C1)NC=1OC(=NN=1)C1=CC=CC=C1)=O)C=CC=C2 Chemical compound C1(=CC=CC=C1)N1C2=C(NC([C@H](C1)NC=1OC(=NN=1)C1=CC=CC=C1)=O)C=CC=C2 FGUUSXIOTUKUDN-IBGZPJMESA-N 0.000 claims description 2
- 230000007423 decrease Effects 0.000 claims 1
- 230000035699 permeability Effects 0.000 abstract description 8
- 239000011148 porous material Substances 0.000 abstract description 2
- 230000001737 promoting effect Effects 0.000 abstract 2
- 238000005336 cracking Methods 0.000 abstract 1
- 239000007789 gas Substances 0.000 description 58
- 208000010392 Bone Fractures Diseases 0.000 description 6
- 206010017076 Fracture Diseases 0.000 description 6
- 230000006378 damage Effects 0.000 description 4
- 230000007547 defect Effects 0.000 description 3
- 230000036961 partial effect Effects 0.000 description 3
- 230000002829 reductive effect Effects 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 238000003795 desorption Methods 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 230000004075 alteration Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000005422 blasting Methods 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000010257 thawing Methods 0.000 description 1
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- 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
- E21B43/2605—Methods for stimulating production by forming crevices or fractures using gas or liquefied gas
-
- 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
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/16—Enhanced recovery methods for obtaining hydrocarbons
-
- 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
- E21B43/16—Enhanced recovery methods for obtaining hydrocarbons
- E21B43/164—Injecting CO2 or carbonated water
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21F—SAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINING IN OR OF MINES OR TUNNELS
- E21F7/00—Methods or devices for drawing- off gases with or without subsequent use of the gas for any purpose
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P90/00—Enabling technologies with a potential contribution to greenhouse gas [GHG] emissions mitigation
- Y02P90/70—Combining sequestration of CO2 and exploitation of hydrocarbons by injecting CO2 or carbonated water in oil wells
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- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Geochemistry & Mineralogy (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Gas Separation By Absorption (AREA)
Abstract
The invention discloses liquid CO 2 Method for promoting gas extraction by alkaline water fracturing and permeability improvement and coal seam water injection, which comprises the steps of immediately placing an iron protection flower pipe and sealing holes after drilling construction, and injecting liquid CO after primary gas extraction 2 The process of secondary gas extraction and high-pressure alkaline water injection realizes the use of liquid CO 2 Endothermic vaporization expansion cracking coal body, promoting secondary development of coal body pore crack structure, high-pressure displacement of adsorbed methane in coal by gaseous carbon dioxide generated by vaporization, and finally alkaline water injection to generate acid-base neutralization reaction to absorb dioxideThe method can effectively increase the air permeability of the coal bed, remarkably improve the gas extraction efficiency and the coal bed water injection effect, simultaneously avoid new gas hazard and have better popularization and application prospects.
Description
Technical Field
The invention relates to the field of coal exploitation, in particular to liquid CO 2 -alkaline water fracturing permeability-increasing gas extraction and coal seam water injection method.
Background
Coal has long been the main source of energy in our country. Along with the continuous increase of the coal exploitation scale and exploitation depth, the permeability of the coal seam is reduced, and the outburst danger of coal and gas is further increased, so that the safety production of a mine is seriously threatened.
At present, gas extraction is one of the most effective ways for solving the gas disasters, most of mines in China have low permeability, the gas extraction difficulty is high, and the coal seam must be artificially enhanced, so that the gas extraction efficiency is improved. At present, methods such as hydraulic fracturing, hydraulic slotting, presplitting blasting and the like are adopted to increase the air permeability of the coal bed, but the conventional coal bed anti-reflection gas extraction method has the defects of small anti-reflection range, difficult expansion of hole cracks of the coal bed near coal body drilling holes, and incapability of further forming a gas extraction crack network, so that the gas extraction rate is low and the gas control effect is not ideal.
In recent years, a large number of coal seam permeability-increasing technologies are applied to gas extraction and achieve a certain achievement. The coal seam water injection and gas phase displacement are common technical measures for inhibiting coal and gas from protruding, but have certain defects, for example, conventional coal seam water injection such as patent CN 113914856A discloses a coal seam water injection device, pressure water enters a drill hole from a water injection hole through a drill bit to infiltrate a coal seam, and the defects of low water content, uneven water distribution and the like exist, so that the water injection effect is poor; gas phase displacement is a method for pumping gas based on liquid nitrogen circulation freeze thawing and anti-reflection of horizontal directional drilling, for example, disclosed in patent CN 105134284B, and new gas outburst risks are easy to form.
Disclosure of Invention
In view of the above-mentioned technical shortcomings, it is an object of the present invention to provide liquid CO 2 Basic water fracturing permeability-increasing gas extraction and coal seam water injection method based on advantages and disadvantages of coal seam water injection and gas phase displacement, and innovatively combines the two methods, and uses liquid CO 2 The method can effectively increase the air permeability of the coal bed, remarkably improve the gas extraction efficiency and the coal bed water injection effect, simultaneously avoid new gas harm, and has better popularization and application prospect.
In order to solve the technical problems, the invention adopts the following technical scheme:
the invention provides liquid CO 2 -an alkaline water fracturing permeability-increasing gas extraction and coal seam water injection method, comprising the following steps:
a. and (3) construction drilling: constructing a gas extraction drilling hole according to the coal seam conditions;
b. placing a protective flower tube and sealing holes: immediately putting the processed protective flower pipes as protective sleeves after drilling construction is completed, wherein the protective flower pipes are tightly attached to the wall of a drilling hole, flower pipe holes are formed in the periphery of the protective flower pipes, and the protective flower pipes are connected in pairs and put into the drilling hole; plugging the part of the drill hole close to the orifice by using plugging materials, wherein an orifice reserved iron pipe is arranged in the middle of the hole sealing part, the tail end of the orifice reserved iron pipe is connected with a flange plate, and a valve is arranged on the flange plate;
c. and (5) gas is extracted for the first time: connecting the drilling flange plate with a gas extraction device through a pipeline, and opening a valve to collect coal bed gas; and along with the extraction process, the gas extraction efficiency is gradually reduced, and after 2-3 months of extraction, the extraction is stopped and the gas extraction device is detached.
d. Injection of liquid CO 2 : drilling flange and injecting liquid CO 2 Device connection, injecting liquid CO into the drill hole 2 Liquid CO 2 Quickly vaporizing after being injected into a drilling hole, and quickly expanding in the vaporization process to promote the development of coal body holes and fissure structures around the drilling hole; due to the protection effect of the pre-buried protection flower pipe, the coal body cannot collapse and block the drilling holes in the process of being subjected to fracturing damage and hole fracture development.
e. Secondary gas extraction: after 2-3 days of injecting liquid carbon dioxide, removing the injected liquid CO 2 The device is used for connecting the flange plate with the gas extraction device again, and desorbing a large amount of adsorbed methane in the coal under the high-pressure displacement action of carbon dioxide; continuing extraction until the extraction working surface is pushed to the drill hole for 20-30m, stopping and dismantling the gas extraction device;
f. high-pressure alkaline water injection: the flange plate is connected to a high-pressure alkaline water injection device, alkaline water with the concentration of 1-10% is injected into the coal bed, the alkaline water and the adsorption carbon dioxide gas in the microporous structure in the coal undergo acid-base neutralization reaction, and the adsorption carbon dioxide gas occupies the original carbon dioxide position under the action of pressure difference.
Preferably, in step f, the concentration of alkaline water is 2%.
Preferably, in the step a, gas extraction drilling holes with the hole depth of 60-120m are constructed every 10m, and the length, the diameter and the angle of the drilling holes are determined according to the occurrence condition of a coal seam and the condition of a mining square drilling machine.
Preferably, in the step b, the protective flower pipe is an iron protective sleeve with a length of 4m each.
Preferably, in the step b, the reserved iron pipe of the hole is an iron pipe with the length being 2-3m longer than the hole sealing length reserved in the middle of the hole, and the diameter of the reserved iron pipe of the hole is smaller than that of the drill hole 3.
The invention has the beneficial effects that:
1. the invention injects liquid CO into the borehole 2 By means of liquid CO 2 The great expansion force and frost heaving force generated during endothermic vaporization have the damage effect on the coal body, the coal body is cracked, the further development of coal body holes and crack structures around the drill hole is promoted, and the coal body cannot collapse and block the drill hole in the process of crack development due to the protection effect of the pre-buried protection flower pipe;
2. the adsorption capacity of the carbon dioxide gas which absorbs heat and vaporizes on the coal is obviously larger than that of methane, the carbon dioxide gas can go deep into the micropore structure of the coal, compete with the adsorbed methane for adsorption and reduce the partial pressure of methane, so that the desorption of the adsorbed methane in the micropore structure of the coal body is promoted, the gas is extracted again at the moment, and the recovery ratio of the coal bed gas is obviously improved;
3. based on the advantages and disadvantages of coal seam water injection and gas phase displacement, the invention creatively combines the two, and the alkaline water is injected to generate acid-base neutralization reaction to absorb CO in the adsorption state in the micropore structure 2 And occupy the original position of the liquid CO, and the liquid CO is injected in the previous step 2 The operation promotes the development of coal body holes and fracture structures around the drilled holes, and a fracture network is established for the coal body holes and fracture structures, so that water is injected into the micropore structures, the water content is high, the water distribution is uniform, the development of the coal body hole fracture structures can be effectively promoted, the permeability of the coal body holes and fracture structures is improved, the coal seam water injection effect is greatly improved, new gas hazards are avoided, and the method has good popularization and application prospects.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art;
FIG. 1 shows liquid CO according to embodiment 1 of the present invention 2 -basic water fracturing permeability-increasing gas extraction and coal seam water injection method schematic diagram;
FIG. 2 is a schematic view of the drill hole protection flowtube of FIG. 1;
reference numerals illustrate:
1. a coal seam; 2. protecting the flower tube; 3. drilling holes; 4. reserving an iron pipe at the orifice; 5. a plugging material; 6. a flange plate; 7. a valve; 8. a gas extraction device; 9. a liquid CO2 injection device; 10. a high-pressure alkaline water injection device; 11. stoping the working face; 12. a flower tube hole; 13. and drilling a hole wall.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Example 1
As shown in fig. 1, liquid CO 2 An alkaline water fracturing permeability-increasing gas extraction and coal seam water injection method,
a. and (3) construction drilling: according to the occurrence condition of the coal seam 1 and related data, constructing gas extraction drilling holes 3 with the hole depth of 60-120m every 10m, and determining the length, diameter and angle of the drilling holes 3 according to the occurrence condition of the coal seam 1 and the condition of a mining square drilling machine.
b. Placing a protective flower pipe 2 and sealing holes: after the construction of the drilling holes 3 is completed, the processed iron protection flower pipes 2 with the length of 4m are immediately placed into the drilling holes 3 as protection sleeves in a pairwise connection mode, the processed iron protection flower pipes 2 are immediately placed into the drilling holes 3 after the construction of the drilling holes 3 is completed, the drilling holes 3 are prevented from collapsing, the protection flower pipes 2 are tightly attached to the drilling hole wall 13, and flower pipe holes 12 are formed in the periphery of the protection flower pipes. Then the part of the drill hole 3 close to the orifice is blocked by a blocking material 5, an iron pipe with the length being 2-3m longer than the hole sealing length is reserved in the middle, the diameter of the reserved iron pipe 4 at the orifice is smaller than that of the drill hole 3, the tail end of the reserved iron pipe 4 at the orifice is connected with a flange 6, and a valve 7 is arranged on the flange 6.
c. And (5) gas is extracted for the first time: and connecting the drilling flange plate 6 with the gas extraction device 8 through a pipeline, and opening the valve 7 to collect the coalbed methane. In the initial stage of extraction, the gas extraction rate is higher, along with the progress of the extraction process, free state and partial adsorption state gas near the drilling hole 3 is extracted, and the gas far away from the drilling hole 3 is lower in permeability of the coal bed 1 and higher in migration resistance, so that the gas extraction efficiency is gradually reduced. And stopping extraction and detaching the gas extraction device 8 after 2-3 months of extraction.
d. Injection of liquid CO 2 : the flange 6 of the drilling hole 3 is injected with liquid CO 2 The device 9 is connected to inject a certain amount of liquid CO into the borehole 3 2 Liquid CO 2 The coal is quickly vaporized after being injected into the drilling hole 3, and is quickly expanded in the vaporization process, and a large amount of heat is absorbed to the surrounding coal, so that huge expansion force and freezing force are generated to the surrounding coal, the coal is cracked, and further development of the hole and crack structures of the coal around the drilling hole 3 is promoted. Due to the protection effect of the pre-buried protection flower pipe 2, the coal body cannot collapse and block the drilling hole 3 in the process of being subjected to fracturing damage and hole crack development. On the other hand, the adsorption capacity of the carbon dioxide gas which absorbs heat and vaporizes on the coal is obviously larger than that of methane, and the carbon dioxide gas can go deep into the interior of the microporous structure of the coal, compete with the adsorbed methane for adsorption and reduce the partial pressure of methane, so that the desorption of the adsorbed methane in the microporous structure of the coal body is promoted.
e. Secondary gas extraction: after 2-3 days of injecting liquid carbon dioxide, removing the injected liquid CO 2 And the device 9 is used for connecting the flange 6 with the gas extraction device 8 again, so that the adsorbed methane in the coal is desorbed in a large amount under the high-pressure displacement action of carbon dioxide, and the gas recovery ratio of the coal bed 1 is obviously improved. And continuing extraction until the extraction working surface 11 is pushed to the drill hole 20-30m, stopping and removing the gas extraction device 8.
f. High-pressure alkaline water injection: the flange 6 was connected to a high-pressure alkaline water injection device 10, and alkaline water having a concentration of 2% was injected into the coal seam 1. Because alkaline water can perform acid-base neutralization reaction with adsorption carbon dioxide gas in the coal microporous structure to absorb carbon dioxide and occupy the original carbon dioxide position under the action of pressure difference, the alkaline water goes deep into the coal microporous structure, and the water injection effect is obviously improved. In addition, the pore and crack structure further develops in the liquid carbon dioxide fracturing process, and the water injection effect is also obviously improved.
The concentration of the alkaline water can be 1-10%, wherein the water injection effect is best when the concentration of the alkaline water is 2%, the water injection amount is high, and the water content of the coal body is distributed more uniformly.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
Claims (5)
1. Liquid CO 2 -an alkaline water fracturing permeability-increasing gas extraction and coal seam water injection method, which is characterized by comprising the following steps:
a. and (3) construction drilling: constructing a gas extraction drilling hole (3) according to the conditions of the coal seam (1);
b. placing a protective flower pipe (2) and sealing holes: immediately putting the processed protective flower pipe (2) as a protective sleeve after the construction of the drilling hole (3) is finished, wherein the protective flower pipe (2) is tightly attached to the wall (13) of the drilling hole, the periphery of the protective flower pipe is provided with flower pipe holes (12), and the protective flower pipe is connected and put into the drilling hole (3); the part, close to the orifice, of the drilling hole (3) is plugged by a plugging material (5), an iron pipe is reserved in the orifice during hole sealing, the tail end of the iron pipe (4) is reserved in the orifice, a flange plate (6) is connected to the tail end of the orifice, and a valve (7) is arranged on the flange plate (6);
c. and (5) gas is extracted for the first time: connecting the drilling flange plate (6) with a gas extraction device (8) through a pipeline, and opening a valve (7) to collect coal bed gas; the gas extraction efficiency gradually decreases along with the extraction process, and after 2-3 months of extraction, the extraction is stopped and the gas extraction device (8) is detached;
d. injection of liquid CO 2 : drilling flange (6) and injecting liquid CO 2 Means (9) are connected to inject liquid CO into the borehole (3) 2 Liquid CO 2 The coal is quickly vaporized after being injected into the drilling hole (3), and the coal is severely expanded in the vaporization process, so that the development of coal holes and fissure structures around the drilling hole (3) is promoted; due to the protection effect of the pre-buried protective flower pipe (2), the coal body cannot collapse to block the drilling hole (3) in the process of crack development;
e. secondary tileAnd (3) S, extraction: after 2-3 days of injecting liquid carbon dioxide, removing the injected liquid CO 2 The device (9) is used for connecting the flange plate (6) with the gas extraction device (8) again, and desorbing a large amount of adsorbed methane in the coal under the high-pressure displacement action of carbon dioxide; continuing extraction until the extraction working face (11) is pushed to the drill hole for 20-30m, stopping and dismantling the gas extraction device (8);
f. high-pressure alkaline water injection: the flange (6) is connected to a high-pressure alkaline water injection device (10), alkaline water with the concentration of 1-10% is injected into the coal seam (1), and the alkaline water and adsorption carbon dioxide gas in the microporous structure in the coal undergo acid-base neutralization reaction and occupy the original carbon dioxide position under the action of pressure difference.
2. Liquid CO according to claim 1 2 -alkaline water fracturing, permeability-increasing, gas extraction promotion and coal seam water injection method, characterized in that in step f, the concentration of alkaline water is 2%.
3. Liquid CO according to claim 1 2 In the step a, a gas extraction drilling hole (3) with the depth of 60-120m is constructed every 10m, and the length, diameter and angle of the drilling hole (3) are determined according to the occurrence condition of a coal bed (1) and the condition of a mining square drilling machine.
4. Liquid CO according to claim 1 2 -alkaline water fracturing permeability-increasing gas extraction and coal seam water injection method, characterized in that in step b, the protective flowtube (2) is an iron protective sleeve with a length of 4m each.
5. In the step b, the reserved iron pipe (4) is an iron pipe with the length being 2-3m longer than the plugging material in the middle of the orifice, and the diameter of the reserved iron pipe (4) is smaller than that of the drilling hole 3.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211094155.7A CN116146160A (en) | 2022-09-08 | 2022-09-08 | Liquid CO 2 Alkaline water fracturing permeability-increasing gas extraction and coal seam water injection method |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211094155.7A CN116146160A (en) | 2022-09-08 | 2022-09-08 | Liquid CO 2 Alkaline water fracturing permeability-increasing gas extraction and coal seam water injection method |
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| CN116146160A true CN116146160A (en) | 2023-05-23 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116771414A (en) * | 2023-08-11 | 2023-09-19 | 华北理工大学 | Mine CO 2 Sealing and gas waterpower cooperative treatment method |
| CN117662229A (en) * | 2023-12-21 | 2024-03-08 | 辽阳正阳机械设备制造有限公司 | Novel coal seam three-phase fracturing permeability-increasing method |
-
2022
- 2022-09-08 CN CN202211094155.7A patent/CN116146160A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116771414A (en) * | 2023-08-11 | 2023-09-19 | 华北理工大学 | Mine CO 2 Sealing and gas waterpower cooperative treatment method |
| CN116771414B (en) * | 2023-08-11 | 2023-11-07 | 华北理工大学 | Mine CO 2 Sealing and gas waterpower cooperative treatment method |
| CN117662229A (en) * | 2023-12-21 | 2024-03-08 | 辽阳正阳机械设备制造有限公司 | Novel coal seam three-phase fracturing permeability-increasing method |
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