CN110972485A - Method for increasing production of coal bed gas by injecting high-temperature air - Google Patents
Method for increasing production of coal bed gas by injecting high-temperature air Download PDFInfo
- Publication number
- CN110972485A CN110972485A CN201780088693.6A CN201780088693A CN110972485A CN 110972485 A CN110972485 A CN 110972485A CN 201780088693 A CN201780088693 A CN 201780088693A CN 110972485 A CN110972485 A CN 110972485A
- Authority
- CN
- China
- Prior art keywords
- temperature
- coal
- gas
- coal bed
- oxygen
- 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.)
- Granted
Links
- 239000003245 coal Substances 0.000 title claims abstract description 471
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 88
- 238000000034 method Methods 0.000 title claims abstract description 65
- 230000001965 increasing effect Effects 0.000 title claims abstract description 63
- 239000007789 gas Substances 0.000 claims abstract description 325
- 239000001301 oxygen Substances 0.000 claims abstract description 130
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 130
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 128
- 238000007254 oxidation reaction Methods 0.000 claims abstract description 125
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 112
- 238000002347 injection Methods 0.000 claims abstract description 111
- 239000007924 injection Substances 0.000 claims abstract description 111
- 230000003647 oxidation Effects 0.000 claims abstract description 100
- 238000001179 sorption measurement Methods 0.000 claims abstract description 66
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 56
- 239000000126 substance Substances 0.000 claims abstract description 28
- 230000000717 retained effect Effects 0.000 claims abstract description 14
- 238000003795 desorption Methods 0.000 claims abstract description 10
- 238000011084 recovery Methods 0.000 claims abstract description 9
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 87
- 238000006243 chemical reaction Methods 0.000 claims description 48
- 230000036284 oxygen consumption Effects 0.000 claims description 41
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 15
- 230000000694 effects Effects 0.000 claims description 14
- 238000010438 heat treatment Methods 0.000 claims description 12
- 239000000203 mixture Substances 0.000 claims description 8
- 230000009467 reduction Effects 0.000 claims description 7
- 238000012544 monitoring process Methods 0.000 claims description 6
- 238000011065 in-situ storage Methods 0.000 claims description 5
- 230000002706 hydrostatic effect Effects 0.000 claims description 3
- 238000012805 post-processing Methods 0.000 claims description 3
- 238000011545 laboratory measurement Methods 0.000 claims description 2
- 230000009471 action Effects 0.000 abstract description 3
- 230000001737 promoting effect Effects 0.000 abstract 1
- 125000000524 functional group Chemical group 0.000 description 20
- 229910002092 carbon dioxide Inorganic materials 0.000 description 19
- 230000008569 process Effects 0.000 description 19
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 17
- 239000000047 product Substances 0.000 description 12
- 238000010521 absorption reaction Methods 0.000 description 10
- 238000011161 development Methods 0.000 description 10
- 239000011148 porous material Substances 0.000 description 9
- 230000007423 decrease Effects 0.000 description 8
- 238000005516 engineering process Methods 0.000 description 8
- 239000001569 carbon dioxide Substances 0.000 description 7
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 6
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 6
- 230000008901 benefit Effects 0.000 description 6
- 238000002485 combustion reaction Methods 0.000 description 6
- 239000003077 lignite Substances 0.000 description 6
- 238000011160 research Methods 0.000 description 6
- 230000002269 spontaneous effect Effects 0.000 description 6
- 230000001133 acceleration Effects 0.000 description 5
- RHZUVFJBSILHOK-UHFFFAOYSA-N anthracen-1-ylmethanolate Chemical compound C1=CC=C2C=C3C(C[O-])=CC=CC3=CC2=C1 RHZUVFJBSILHOK-UHFFFAOYSA-N 0.000 description 5
- 239000003830 anthracite Substances 0.000 description 5
- 230000006866 deterioration Effects 0.000 description 5
- 229910052683 pyrite Inorganic materials 0.000 description 5
- 230000004913 activation Effects 0.000 description 4
- 239000000470 constituent Substances 0.000 description 4
- 230000006870 function Effects 0.000 description 4
- 230000007246 mechanism Effects 0.000 description 4
- 238000004375 physisorption Methods 0.000 description 4
- NIFIFKQPDTWWGU-UHFFFAOYSA-N pyrite Chemical compound [Fe+2].[S-][S-] NIFIFKQPDTWWGU-UHFFFAOYSA-N 0.000 description 4
- 239000011028 pyrite Substances 0.000 description 4
- 229910052786 argon Inorganic materials 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 3
- 239000001307 helium Substances 0.000 description 3
- 229910052734 helium Inorganic materials 0.000 description 3
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 3
- 239000011261 inert gas Substances 0.000 description 3
- 229910052743 krypton Inorganic materials 0.000 description 3
- DNNSSWSSYDEUBZ-UHFFFAOYSA-N krypton atom Chemical compound [Kr] DNNSSWSSYDEUBZ-UHFFFAOYSA-N 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 238000005065 mining Methods 0.000 description 3
- 239000003345 natural gas Substances 0.000 description 3
- 229910052754 neon Inorganic materials 0.000 description 3
- GKAOGPIIYCISHV-UHFFFAOYSA-N neon atom Chemical compound [Ne] GKAOGPIIYCISHV-UHFFFAOYSA-N 0.000 description 3
- 230000001590 oxidative effect Effects 0.000 description 3
- 229910052704 radon Inorganic materials 0.000 description 3
- SYUHGPGVQRZVTB-UHFFFAOYSA-N radon atom Chemical compound [Rn] SYUHGPGVQRZVTB-UHFFFAOYSA-N 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 230000007704 transition Effects 0.000 description 3
- 229910052724 xenon Inorganic materials 0.000 description 3
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 description 3
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 230000000996 additive effect Effects 0.000 description 2
- 125000004429 atom Chemical group 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000003197 catalytic effect Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 229910052500 inorganic mineral Inorganic materials 0.000 description 2
- 239000011707 mineral Substances 0.000 description 2
- 150000002926 oxygen Chemical class 0.000 description 2
- 125000004430 oxygen atom Chemical group O* 0.000 description 2
- 230000036632 reaction speed Effects 0.000 description 2
- 239000011435 rock Substances 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- 239000011593 sulfur Substances 0.000 description 2
- MGWGWNFMUOTEHG-UHFFFAOYSA-N 4-(3,5-dimethylphenyl)-1,3-thiazol-2-amine Chemical compound CC1=CC(C)=CC(C=2N=C(N)SC=2)=C1 MGWGWNFMUOTEHG-UHFFFAOYSA-N 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- 241000195493 Cryptophyta Species 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 235000004522 Pentaglottis sempervirens Nutrition 0.000 description 1
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000011358 absorbing material Substances 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 125000001931 aliphatic group Chemical group 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 229910052925 anhydrite Inorganic materials 0.000 description 1
- 150000008365 aromatic ketones Chemical group 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000002802 bituminous coal Substances 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 238000004939 coking Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000012084 conversion product Substances 0.000 description 1
- 239000007799 cork Substances 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 238000009533 lab test Methods 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- 229910052960 marcasite Inorganic materials 0.000 description 1
- 239000003550 marker Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 description 1
- 125000001741 organic sulfur group Chemical group 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000005215 recombination Methods 0.000 description 1
- 230000006798 recombination Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000002336 sorption--desorption measurement Methods 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000006557 surface reaction Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 239000004079 vitrinite Substances 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP 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
- E21B43/18—Repressuring or vacuum methods
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP 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
- E21B43/24—Enhanced recovery methods for obtaining hydrocarbons using heat, e.g. steam injection
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP 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
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
- E21B47/06—Measuring temperature or pressure
-
- 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
Abstract
A method for injecting high-temperature air into a coal seam to increase the yield of coal seam gas. The method comprises the steps of injecting high-temperature air into a coal bed from one or more gas injection wells, stripping and expelling adsorbed coal bed gas on the surfaces of coal micropores and fractures by nitrogen, promoting the desorption of the coal bed gas and transporting the coal bed gas to a production well, enabling oxygen in the coal bed gas to be retained in the coal bed or consumed due to physical adsorption, chemical adsorption and oxidation reaction under the action of low-temperature oxidation, collecting the coal bed gas or mixed gas of the coal bed gas and the nitrogen from the multiple production wells, and improving the yield of the coal bed gas well and the recovery ratio of the coal bed gas. The same or better yield increasing effect can be obtained by injecting high-temperature air.
Description
The invention relates to a method for increasing coal bed methane by injecting high-temperature air into a coal bed methane reservoir. In particular, the invention relates to a method for injecting high-temperature air into a coal seam from one or more wells (hereinafter referred to as "gas injection wells") communicated with the coal seam, wherein nitrogen in the coal seam "strips" and "drives off adsorbed coal seam gas on the surfaces of coal micropores and cracks, desorption of the coal seam gas is promoted, the coal seam gas is transported to a production well, oxygen in the coal seam gas is retained in the coal seam or consumed by low-temperature oxidation due to physical adsorption, chemical adsorption and oxidation reaction, and produced coal seam gas and mixed gas of the coal seam gas and the nitrogen are collected from the one or more wells (hereinafter referred to as" production wells ") communicated with the coal seam, so that the yield of the coal seam gas well and the recovery rate of the coal seam gas are improved.
Coal bed gas is natural gas in coal beds, also called gas, and the main component of the coal bed gas is methane. The coal bed gas is not only a clean energy source of natural gas, but also a cause of coal mine gas outburst and explosion.
Worldwide coal bed gas reserves are huge and yields are low because the "drilling-fracturing-draining-depressurizing-gas producing" technical model from the united states, which is used in current coal bed gas development, can only develop the best-quality coal bed gas reservoir and is not suitable for most coal bed gas reservoirs. This consistent failure of current mainstream coal bed gas development technology has resulted in coal bed gas blocks that recapture investment and profit or have this prospect being a low probability lucky event, both world and china. The world coal bed gas industry has not declined, with only a few exceptions to success. Only by developing a new coal bed gas development technology suitable for the country according to the respective national conditions, all countries in the world can develop coal bed gas resources of the country with economic benefits.
In 1998, Puri and Stein proposed a method for increasing the production of coal bed gas by injecting inert gas (e.g., nitrogen) or gas that does not chemically react with coal (e.g., CO) from a gas injection well into the coal bed2) Obtaining coal bed gas from one or more production wells can increase the production of coal bed gas (see Rajen Puri and Michael h. steel. 1988. Method of coalbed methane production. U.S. patent No. 4883122). The patent methods of Puri and Stein are only suitable for high-quality coal bed gas reservoirs with high permeability, are inapplicable to most coal bed gas reservoirs and cannot be implemented. In 2015, Chenyiping provides a nitrogen-injection yield-increasing coal bedThe pressure control method of gas is suitable for nitrogen injection, degradation, increase and production of coal bed gas of any coal bed (refer to Chen Xin Ping. 2015. pressure control method of nitrogen injection, increase and production of coal bed gas. Chinese patent No. ZL 201510467978.3). The Chen Xinping patent method takes parameters such as wellhead pressure, gas production rate, and volume percentage content change of nitrogen of a production well as the reaction of a coal bed gas reservoir to nitrogen injection pressure and nitrogen injection rate of a nitrogen injection well, feeds the parameters back to the nitrogen injection well, and adjusts the nitrogen injection pressure and the nitrogen injection rate, so that nitrogen can be injected into a low-permeability coal bed without fracturing surrounding rocks of a coal bed roof and a bottom plate.
CO injection2The coal bed gas production increase is high in cost, and the gas coal bed is converted into a carbon dioxide coal bed. For coal mining, CO2As harmful as methane, even CO2The harm is greater because of CO2And more difficult to pump. Australia has a large amount of high CO2Coal bed due to CO2Difficult to be controlled and cannot be exploited. Therefore, CO injection2Increasing production of coal bed methane is not a coal bed methane development technology that can be widely used.
Note N2Increasing the coal seam gas does not substantially harm future coal mining operations, however, note N2The high cost of the coal bed gas production is influenced by N injection2The popularization and application of the coal bed gas increasing technology. Note N2The cost of the coal bed gas increasing technology is about 0.50 yuan/m3Left and right. The current price of the coal bed gas wellhead is 1.20-1.50 yuan/m3In the meantime. Note N2The cost accounts for 42-33% of the sale benefit of the coal bed gas, and the proportion is too heavy, so that the N injection is carried out2Increasing production of coal bed gas is not economically efficient in most cases. Note N2The cost of the coal bed gas production increasing technology is composed of two parts: (1) separating nitrogen from air by using a nitrogen making machine or a cryogenic method, mainly separating oxygen from nitrogen; and (2) injecting nitrogen into the coal seam using a high pressure booster. The two parts are substantially equal in cost. Thus, if the coal seam can be injected with air instead of nitrogen, N is obtained and injected2The yield increase effect of coal bed gas is the same or better, and the cost is only equivalent to the N injection2Half of the cost of increasing the coal bed gas, so the method for increasing the coal bed gas by injecting air has great use valueThe value of the coal bed gas is to be a great contribution to the development of the coal bed gas in the world.
Disclosure of Invention
The invention relates to a method for increasing coal bed methane by injecting high-temperature air into a coal bed methane reservoir. In particular, the invention relates to a method for injecting high-temperature air into a coal seam from one or more wells (hereinafter referred to as "gas injection wells") communicated with the coal seam, wherein nitrogen in the coal seam "strips" and "drives off adsorbed coal seam gas on the surfaces of coal micropores and cracks, desorption of the coal seam gas is promoted, the coal seam gas is transported to a production well, oxygen in the coal seam gas is retained in the coal seam or consumed by low-temperature oxidation due to physical adsorption, chemical adsorption and oxidation reaction, and produced coal seam gas and mixed gas of the coal seam gas and the nitrogen are collected from the one or more wells (hereinafter referred to as" production wells "), so that the yield of the coal seam gas well and the recovery rate of the coal seam gas are improved.
The invention is realized by adopting the following technical means:
the invention relates to a method for increasing coal bed methane by injecting high-temperature air into a coal bed methane reservoir. In particular, the invention relates to a method for injecting high-temperature air into a coal seam from one or more wells communicated with the coal seam, wherein nitrogen in the high-temperature air "strips" and "drives" coal-bed methane in an adsorption state on the micropore and fissure surfaces, the desorption of the coal-bed methane is promoted, the coal-bed methane is transported to a production well, oxygen in the coal-bed methane is retained in the coal seam or consumed due to physical adsorption, chemical adsorption and oxidation reaction due to low-temperature oxidation, and the produced coal-bed methane and mixed gas of the coal-bed methane and the nitrogen are collected from the one or more wells communicated with the coal seam, so that the yield of a coal-bed gas well and the recovery rate of the coal.
The specific implementation steps and characteristics of the method for increasing the yield of the coal bed methane by injecting high-temperature air into the coal bed are as follows:
(a) determining the initial temperature, the heating rate, the normal operation temperature and the accelerated oxygen consumption temperature of air injected into the coal bed according to the characteristics of the coal bed gas reservoir;
(b) starting gas injection operation according to the initial temperature and the heating rate at the gas injection starting stage until the gas injection temperature reaches the normal operation temperature, and entering the normal gas injection yield increasing operation stage;
(c) monitoring the bottom pressure and temperature of the gas injection well, and monitoring the gas composition, the bottom pressure and temperature, the top pressure and temperature of the production well;
(d) when the moisture content in the gas of the production well is obviously reduced, a water injection high-pressure switch in a gas injection well mouth or a gas injection pipeline is opened, and the water injection high-pressure switch of the gas injection well mouth is closed until the moisture content in the gas of the production well is recovered to be normal;
(e) when the oxygen content in the gas of the production well is abnormally increased or the oxygen content in the gas of the production well exceeds the standard specified by the coal bed gas production specification, raising the gas injection temperature to the accelerated oxygen consumption temperature, and reducing the gas injection temperature to the normal operation temperature until the oxygen content in the gas of the production well is recovered to be normal;
(f) determining the highest allowable gas temperature of the production well according to the characteristics of the coal bed gas reservoir and the performance of the coal bed gas post-processing equipment;
(g) when the gas temperature of the production well is increased to be close to the highest allowable temperature, stopping gas injection operation until the bottom hole pressure of the production well is reduced to be close to the hydrostatic pressure of a coal bed gas reservoir or until the gas yield of the production well is reduced to be close to an economic threshold value, starting gas injection operation according to the initial temperature and the temperature rise rate according to the operation program of the gas injection starting stage until the gas injection temperature reaches the normal operation temperature, and entering the normal gas injection yield-increasing operation stage again;
(h) when the gas temperature of the production well is increased to be close to the maximum allowable temperature and the temperature reduction effect of the step (g) is poor or the step (g) cannot be implemented due to the poor temperature reduction effect, injecting normal-temperature air or normal-temperature nitrogen again until the gas temperature of the production well is sufficiently reduced, starting gas injection operation according to the initial temperature and the temperature increase rate according to the operation program of the gas injection starting stage until the gas injection temperature reaches the normal operation temperature, and entering the normal gas injection yield-increasing operation stage again;
(i) steps (d), (e), (g) and (h) may be repeated as many times as necessary.
Compared with the prior art, the method has the following obvious beneficial effects and advantages:
firstly, the bookThe method injects air into the coal bed, and nitrogen in the air is stripped and drives off the adsorbed coal bed gas on the surface of the coal micropore, so that the desorption of the coal bed gas is promoted and the coal bed gas is transported to a production well, and the N injection is realized2Increasing production of nitrogen in coal bed gas and increasing production effect and injecting N2The yield increasing effect of increasing the yield of coal bed gas is similar.
Secondly, the method of the invention does not need to separate nitrogen and oxygen, the low-temperature oxidation of the coal replaces a nitrogen making machine, and the cost is only equivalent to the N injection2The cost of producing the coal bed gas is increased by half, and the cost of intensively developing the coal bed gas is effectively reduced.
Thirdly, the high-temperature air injected into the coal seam by the method directly increases the temperature of the coal seam, and the physical adsorption, chemical adsorption and chemical reaction in the low-temperature oxidation of the coal are all exothermic, so that the temperature of the coal seam is also increased. According to the research, the adsorption quantity of the coal to the methane is reduced by about 0.18m on average from 30 ℃ to 40 ℃ and every 1 ℃ rise of the temperature3Perton (see Fuxuehai, Qin Yong, Wei Doau 2007. coal bed gas geology [ M]Section four of chapter iv. Beijing: china university of mining publishers). Therefore, the method provided by the invention has the advantages that the temperature of the coal bed is increased, the desorption of the coal bed gas is promoted, the recovery ratio of the coal bed gas can be increased, and the residual gas content of the coal bed is reduced to a lower level.
The world coal bed gas reserves are huge, and the output is very low because the currently used coal bed gas development technology can only develop the coal bed gas reservoir with the best quality and is not suitable for most coal bed gas reservoirs. The technology provided by the invention can develop most coal bed gas reservoirs, so that huge coal bed gas resources benefit mankind.
FIG. 1 is a graph showing the trend of oxygen absorption for different coal types at different adsorption ambient temperatures.
FIG. 2 is a graph of oxygen consumption by low temperature oxidation of coal as a function of temperature.
FIG. 3 shows the oxygen consumption of coal by oxidation of coal at different temperatures for 1 hour.
FIG. 4 shows the results of oxygen consumption measurements for the same coal at the same temperature and different oxidation times.
FIG. 5 is a schematic diagram showing the temperature of the coal bed around the gas injection well and the low-temperature oxidation of coal 4 years after injecting high-temperature air.
The present invention will be further described with reference to the following embodiments.
Theoretical main points of low-temperature oxidation of coal
In the scientific literature, "low-temperature coal oxidation" refers to the physical, physico-chemical, and chemical actions that occur between coal and oxygen in an oxidation environment below the ignition point of coal. The coal ignition point rises along with the rise of the coal rank from the ignition point of lignite (270-310 ℃) to the ignition point of coking coal (350-370 ℃). The low-temperature oxidation of coal refers to the physical, physical-chemical and chemical actions between coal and oxygen elements in an oxidation environment far below the ignition point of coal in a gas-injected coal bed, or in other words, the low-temperature oxidation of coal is limited to a stable oxidation reaction process in which the generated heat is equal to the dissipated heat, and does not include a stage in which the oxidation reaction is automatically accelerated to achieve uncontrollable spontaneous combustion.
The coal industry has comprehensively and fully researched the problem of low-temperature oxidation of coal for a long time, because the low-temperature oxidation stage is the initial stage of spontaneous combustion of coal and plays a decisive role in the development of spontaneous combustion of coal, and the research on the coal oxidation characteristics in the stage is of great significance for disclosing the mechanism of spontaneous combustion of coal and making countermeasures from the source to prevent coal mine fire, the coal industry has proved that the basic theory of low-temperature oxidation of coal is correct and reliable in the aspects of low-temperature oxidation of coal, Guo development, experimental equipment development, laboratory simulation tests, numerical simulation, production application and the like, although there are disputes between different viewpoints due to the extremely complicated and variable coal structure, there are numerous incomplete clearness points, the following statements are closely related to the invention and are obtained the coal low-temperature oxidation theory of coal which is universally acknowledged in the coal industry (see the technical theory of low-temperature oxidation of coal, Lebaoqing, 1995, the coal conversion with spontaneous combustion of coal, 18(1), (10-17) of coal, ② Daihong coal, the Lai-Daihong-Miao Lai et Gekken research on the coal, No. 5, No. 5, (No. 5, No. 11, No. 8, No. 4, No. 8, No. 4, No. 8, No. 4, No. 1:
● all coals, including anthracite coals, all coal and rock compositions, including inert components, are susceptible to oxidation, although the degree of oxidation sensitivity varies widely from coal to coal and from coal to coal composition.
● active structures capable of reacting with oxygen are present in coal at almost any temperature condition. The coal has a plurality of functional groups in the structure, and the element composition and the structure of the functional groups are greatly changed, so that the activity of the coal is greatly changed, and the coal has different oxidizing capacities; the functional groups and the coal structure main body can influence each other, so that the activity of the coal structure main body is changed, and the oxidizing capability of the functional groups is changed; this allows for the interaction of coal oxygen in the coal mass at almost any temperature condition.
● the number of functional groups such as aromatic ketone, aldehyde carbonyl, phenol, alcohol, ether, ester oxygen bond, etc. increases or increases from nothing to nothing with the increase of the oxidation temperature. Such functional groups are primarily oxygen-containing functional groups because during oxidation of coal, oxygen atoms are bonded to the more reducing functional groups. Thus, such functional groups increase in number with increasing temperature during low temperature oxidation.
● the majority of the functional groups decrease in number with increasing oxidation temperature, even after a certain temperature at which a functional group is no longer present. The functional groups generally belong to aliphatic structures, are mostly positioned in branched chain parts in the coal molecular structure and show stronger reducibility.
● the temperature at which the same functional group oxidizes in coal samples of different coal grades is different, and the temperature at which the same functional group oxidizes in different coal samples of the same coal grade may also be different due to the different main structures in which the functional groups are located. The host structure affects the oxidizability of the functional group.
● the main structure of the coal structure is not changed basically in the low-temperature oxidation process of the coal. Because the main structure of the coal structure needs higher energy to be activated to generate oxidation reaction, the main structure of the coal structure is not obviously changed under the low-temperature oxidation condition below 200 ℃.
● the coal will be physically adsorbed and chemically adsorbed on contact with oxygen to release heat, so that the coal is most easily activated, i.e. the structure with lower activation energy is activated by the heat released by physical adsorption and chemical adsorption, and then reacts with oxygen to release reaction products including index gas while releasing heat; the energy of the system is further increased along with the rise of the temperature of the coal body caused by the heat released by the initial oxidation reaction, so that other functional groups requiring larger activation energy (higher temperature) are activated to perform chemical reaction, more heat is released, the temperature of the coal body is further increased, the energy of the system is further increased, and the structure and the functional groups requiring larger activation energy are activated to perform oxidation reaction, so that the temperature of the coal body is continuously increased. However, this auto-acceleration of the oxidation reaction will slow down and stop due to insufficient oxygen supply.
● influence the intrinsic factors of low temperature oxidation of coal:
■ degree of rank (or degree of coalification, degree of coal deterioration) it is generally believed that the activity of low temperature oxidation of coal decreases with increasing degree of coalification one of the reasons is that low rank coal has a higher oxygen content and an increased chemical binding capacity for moisture, making the coal more hydrophilic and more reactive to oxidation.
■ Sulfur content the oxidation of pyrite is believed to produce an exothermic effect that favors the continued oxygen consumption between coal and oxygen, increasing the rate of oxygen consumption inorganic and organic sulfur in coal behave differently in the oxidation reaction, pyrite oxidation is significant at low temperatures (e.g., 25℃.) and is more pronounced at high temperatures (e.g., 80℃.) the mechanism of sulfur oxidation is pyrite (FeS)2) By-product of oxidation H2SO4Not only improves the solubility and leaching capability of minerals in the coal, but also plays a catalytic role in the reaction of oxidizing C-H in the micro-components into oxygen-containing functional groups, thereby being rich in FeS2The coal is easily oxidized. In addition, the particle size distribution of pyrite, the ability of carbonates in the coal to neutralize acids, etc. can also affect the rate of oxidation.
■ porosity and pore structure, porosity, pore connectivity and internal surface area are all favorable to low temperature oxidation of coal, because these factors determine whether air can easily enter the coal, contact the effective surface area, enter reactive vacancies.
■ other factors include low-temperature coal oxidation, easy oxidation of vitrinite, algae and spore, relative difficulty in oxidation of filamentous, horny or cork, and calcium component (CaCO)3And its conversion product CaSO4) It has catalytic action to low-temp oxidation of coal.
● influence the external factors of low temperature oxidation of coal:
■ temperature, when other conditions are not changed, the temperature is different, the chemical reaction speed is different, so the oxygen consumption rate of coal is different, the chemical reaction constant and the surface reaction heat are functions of temperature, the oxygen consumption rate and the oxidation heat release intensity of the coal sample are increased with the increase of the temperature, the higher the temperature is, the larger the amplitude of the oxygen consumption rate and the heat release intensity with the increase of the temperature is, the generation amount of the oxidation gas is increased with the increase of the oxidation temperature, and the generation amount of most gases is increased according to an exponential law with the increase of the temperature.
■ time although the process of oxygen adsorption is fast at temperatures well below the coal ignition point, the oxidation process is slow, the heat generated by the oxidation process equals the heat dissipated, the oxidation does not enter into an auto-acceleration process, and thus, a stable oxidation process.
■ oxygen concentration, oxygen is the material base of coal oxygen reaction, the oxidation reaction of the surface active structure of the coal is directly influenced by the oxygen concentration of the environment where the coal is located, the oxygen concentration is different, the oxygen consumption rate of the coal is different, the acceleration rate of the oxidation reaction is different, and the acceleration limit is different.
■ moisture is considered to be both intrinsic, because moisture is one of the important constituents of coal, and external, because external intervention can greatly change the moisture content of coal moisture affects both the physical adsorption of coal to oxygen and the chemical reaction between coal and oxygen.
● products of coal low-temperature oxidation process
■ gaseous product generated during low-temperature oxidation of coal, and the common gaseous products include CO and CO2、CH4、C2H6、C3H6、C2H4、H2O, etc., see also H2、C3H8、C2H2、C4H10、iC4H10And the like.
◆ removing CO2And H2Besides O, gaseous products generated in the low-temperature oxidation process of coal are all combustible gases.
◆ different coal types generate the same gas at different temperatures and at different gas production rates, for example, lignite can produce CO by oxidation at room temperature, whereas anthracite can produce CO by oxidation at temperatures above 80 deg.C.
◆ different initial and final temperatures of different gases produced by the same coal species, each gas produced within a specific temperature range, although the temperature ranges of the gases may overlap or partially overlap2H6Gas, oxidation at 90 ℃ to C2H4Gas, oxidation at 120 ℃ to C3H8Gas, oxidation at 140 ℃ to H2The gas is oxidized at 160 ℃ to generate C along with the oxidation deepening2H2A gas.
◆ the types and the sequence of the gases generated by different coal types are different, even the types and the sequence of the gases generated by coal samples in different areas of the same coal type are different, for example, researchers find that under the same temperature rise experiment conditions, the types and the sequence of the gases generated by the oxidation of lignite are CO and C2H6、C2H4、C3H8、H2、C2H2(ii) a The gas produced by gas coal oxidation is CO and C in the order2H4、H2(C2H6Already present at the beginning of the experiment); the category and the sequence of the gas generated by the oxidation of the gas fat coal are CO and C2H4、H2(C2H6、C3H8Already present at the beginning of the experiment); the category and the sequence of the gas generated by the oxidation of the anthracite are CO and H2Although the temperature is raised from 20 ℃ to 210 ℃, C is not generated by oxidation2H6、C2H4、C3H8。
◆ indicator gas (or marker gas) the gas originally present in the coal seam and produced entirely by coal oxidation is referred to as "indicator gas"2H4Is also a commonly used indicator gas.
■ non-gaseous products-indeed, it has not been known to date exactly what non-gaseous products and their quantities were produced during the low temperature oxidation of coal, largely because it was difficult to distinguish the original constituents of coal from the non-gaseous products.
● mechanism of low-temperature oxidation of coal: due to the differences in rank (type of coal), grade (quality) of coal, micro-components and content thereof, mineral components and content thereof, structure, porosity and pore structure of coal, oxidation temperature, oxygen concentration, etc., due to the complexity of the low-temperature oxidation reaction itself, and the differences in research means (reaction apparatus, type of coal, amount of coal, and analysis techniques) employed by many researchers, there are many consensus and opposite opinions on the research of the low-temperature oxidation mechanism of coal. The present invention sets forth a consensus among many researchers for the primary purpose of clarifying the process of the present invention without pursuing all-inclusive. The low-temperature oxidation process of coal can be divided into three stages
The coal has a tendency to spontaneously reduce the interfacial energy, the solid interface is difficult to shrink due to the inability of surface molecules or atoms to move freely, and the surface free energy is reduced only by adsorption of other molecules, which creates an artifact of adsorption at the surface of the coal.
■ chemical adsorption and local chemical reaction stage, where chemical adsorption is the transition process from physical adsorption of coal to chemical reaction, or transition state, chemical reaction occurs between oxygen and coal surface structure, and the oxygen atom transfers with the atom in coal structure and combines with surface bond force similar to chemical bondThe coal and oxygen react rapidly to generate oxidation products, heat is released, part of the oxidation products are chemically adsorbed to generate unstable complexes, and the unstable complexes are decomposed into gaseous products and solid compounds, and heat is released simultaneously. The accumulation of these two portions of heat results in an increase in temperature, which promotes the oxidation of the coal into the next stage. At this stage, the gas products produced are mainly CO, CO2、H2O。
■ chemical reaction stage, which can be divided into two sub-stages connected in series:
◆ autothermal oxidation stage in which the oxidation rate increases with increasing coal temperature, the oxidation of the fatty side chain produces gaseous hydrocarbons, C2H4，C2H6And C3H8。
◆ accelerated oxidation stage, deep oxidation, oxidation of partial bridge bond on coal molecular structure unit, high reaction speed, and generation of H2And C2H2。
◆ the chemical reactions at this stage are not limited to surface chemical reactions and may be deep inside the coal structure, however, the chemical reactions at this stage are still limited to side chains, bridges, functional groups of the coal structure and do not involve the main structure of the coal.
Technical key points and difficult points of method for increasing production of coal bed gas by injecting high-temperature air
On the basis of the theory of low-temperature oxidation of coal, the invention states the technical key points and the detailed difficult points of the method for increasing the yield of coal bed gas by injecting high-temperature air, and mainly how to consume the oxygen in the air injected into the coal bed? How does oxygen not become consumed remain in the coal seam and not be removed from the production well along with the coal seam gas and nitrogen?
● composition of air: the normal air composition is calculated by volume fraction: nitrogen (N)2) About 78.07% oxygen (O)2) About 20.94%, rare gas about 0.93% (helium He, neon Ne, argon Ar, krypton Kr, xenon Xe, radon Rn), carbon dioxide (CO)2) About 0.031%, and other gases and impurities about 0.03% (e.g., ozone (O)3) Nitrogen monoxide (NO), nitrogen dioxide (NO)2) Water vapor (H)2O), etc.).
● the components of air injected into coal seam and the components of gas generated during low-temperature oxidation of coal
■ Nitrogen (including helium, neon, argon, krypton, xenon, radon) rare gases such as helium, neon, argon, krypton, xenon, radon are inert gases with the same properties and the same functions and sinks, so nitrogen is taken as a representative for discussion, nitrogen is used for stripping and expelling coal-bed gas in adsorption state on the surface of coal micropores and cracks to promote the desorption of the coal-bed gas and to move to a production well, the yield increasing effect of injecting high-temperature air to increase the coal-bed gas is mainly born by nitrogen, the principle of nitrogen to increase the coal-bed gas is referred to U.S. Pat. No. 4883122 and Chinese patent No. 201510467978.3, which does not describe that a small part of nitrogen is adsorbed by the coal bed and stays in the coal bed, most of nitrogen is transported to the production well along with the coal-bed gas which is expelled and discharged to the coal-bed gas gathering system and finally returns to the atmosphere, and the percentage of nitrogen in the production well is zero or close to zero at the initial stage as the gas injection time is prolonged.
■ carbon dioxide (including carbon dioxide generated by low-temperature oxidation of coal) coal bed has strong CO adsorption2Due to CO2Higher gram molecular weight and coal to CO2Resulting in CO2Has a large Langmuir volume and a low Langmuir pressure. Thus, trace amounts of CO in the high temperature air injected into the coal seam2And carbon dioxide generated by low-temperature oxidation of coal, most of which is adsorbed by the coal bed and is retained in the coal bed, and only trace amount of CO is possible2To the production well. This is a theory that has been demonstrated by the flow of multicomponent multiphase fluids in adsorption desorption porous media (see Zhu, J.2003.multicomponent multiphase flow in pore media with temperature variation or adsorption, Ph.D. separation, Standard University, Online athttp://pangea.stanford.edu/ERE/pdf/pereports/PhD/Zhu03.pdf) Also confirmed by a number of laboratory experiments (see Parakh, S.,2007, Experimental Investigation of Enhanced cobalt Bed Methane Recovery, Ph.D. discovery.Stanford University)。CO2The coal bed gas in the adsorption state is replaced while being adsorbed by the coal bed, and the coal bed gas is also increased (see Yejianping, Von Sanli, Fanzhi, Wang Guo Qiang.2007. Mini pilot test research on improving the recovery ratio of the coal bed gas by injecting carbon dioxide in south of Qin Water basin. Petroleum institute, 28(4): 77-80).
■ gas generated during low temperature oxidation of coal (except CO)2External): h2O originally is one of the components of the coal bed gas, enters the gathering and transportation system as one of the gas components of the production well, and is dehydrated and removed by the post-treatment equipment. CO removal2And H2Besides O, gaseous products generated in the low-temperature coal oxidation process are combustible gases, and the calorific values of the gaseous products are much higher than that of the main component methane of the coal bed gas and are high-calorific-value natural gas components. The additive is used as a coal bed gas component and is discharged into a coal bed gas gathering and transportation system from a production well, and the additive is beneficial and harmless to the production of the coal bed gas.
■ oxygen the role and destination of oxygen is the most complex and critical to the success of injecting high temperature air to increase the production of coal bed gas, and needs to be discussed in detail as follows:
◆ is retained in the coal seam, free oxygen is retained in the coal seam in three forms.
◆ oxygen consumption is shown in FIG. 2 as the oxygen consumption of a lean coal and an anthracite coal changes with temperature (see Yiweidan, Wangming, Zhongxing. 2010. study on activation energy for coal low-temperature oxidation reaction based on oxygen consumption; 2010(07):12-15) as the vertical axis shows the difference between oxygen concentration of inlet gas and oxygen concentration of outlet gas of experimental device, the larger the difference shows the oxygen consumption of low-temperature oxidation reaction, FIG. 2 shows the overall trend of decreasing and then increasing as the oxygen consumption increases when coal is in contact with oxygen, the adsorption process is very fast, the physical adsorption can reach about 80% of saturation oxygen uptake in seconds, the spontaneous combustion rate then decreases, the adsorption equilibrium is finally reached, the physical adsorption gradually transitions to chemical adsorption, the chemical reaction between coal oxygen begins, the oxygen consumption increases, and the oxygen consumption increases as the temperature increases to a specific temperature range, the oxygen consumption increases as the oxygen consumption increases in seconds, the oxygen consumption increases from the atmospheric temperature of coal to the atmospheric temperature, the atmospheric temperature of coal is shown in the same table, the atmospheric temperature of coal, the atmospheric temperature is shown in the atmospheric temperature of coal, the atmospheric pressure of coal is shown in the atmospheric pressure chart 1.1.4. the atmospheric pressure, the atmospheric pressure of the atmospheric pressure, the atmospheric pressure of the.
TABLE 1 oxygen consumption of coal oxidation at 70 deg.C for 1 hour for different coal types
TABLE 2 oxygen consumption of coal oxidation at different temperatures for 1 hour for the same coal type
TABLE 3 oxygen consumption test results for the same coal type at the same temperature and different oxidation times
● the majority of oxygen will be retained in or consumed by the coal seam: the foregoing theoretical points of low temperature oxidation of coal and the discussion of the role and fate of the constituents of the air injected into the coal bed and the constituents of the gas produced during low temperature oxidation of coal have ensured that a substantial portion of the oxygen is retained or consumed in the coal bed. To more clearly illustrate how oxygen in the air is retained in the coal seam or consumed in the coal seam, fig. 5 schematically shows the temperature conditions of the coal seam around the gas injection well 4 years after injecting high temperature air, the coal seam being assumed to be lignite. In the drawing of fig. 5, it is assumed that the characteristics of the coal bed gas reservoir are isotropic, the heat conduction of the high-temperature gas to the coal bed is the same in all directions, and the heat conduction between different portions of the coal bed itself is the same in all directions, so that the temperature rise of the coal bed due to the injection of the high-temperature gas is the same in all directions. Fig. 5 is a plan view, i.e. a bird's eye view, of the temperature of the coal seam around the nitrogen injection well, which is increased by injecting high-temperature gas under the assumed condition. In FIG. 5, the central black circle is the gas injection well with a gas injection temperature of 150 ℃; on the right side horizontal line of cross, outside-in has marked the radius of 1 st, 4 th, 6, 9 concentric circles in proper order: 300m, 254m, 200m, 100 m; on the lower part vertical line of cross, from bottom to top, marked the temperature of 1 st, 4 th, 6, near 9 concentric circles position coal seams in proper order: 40 ℃, 43 ℃, 50 ℃ and 70 ℃. In this figure, the central set of thick black concentric circles indicate the range of coal bed temperatures greater than 70 ℃; the middle set of thin black concentric circles indicates the temperature of the coal bed in the range of 70-43 ℃, and the radius of the last thin black concentric circle is about 245 m; four gray filled black circles on the thin black concentric circle represent four production wells closest to the gas injection well, which is equivalent to a first circle of production wells of the 250 m-250 m coal bed gas well pattern surrounding the gas injection well; the outer concentric circles of black dashed lines indicate the range of coal seam temperatures less than 43 c, which is not limited to the concentric circles of black dashed lines in the figure, but expands outward until abutting the influence range of the adjacent gas injection well. The influence range of one gas injection well is determined by the characteristics of the coal bed gas reservoir, gas injection operation parameters, gas injection time length and other factors, and ranges from hundreds of meters to thousands of meters. The coal bed is assumed to be lignite, and the low-temperature oxidation of the coal is mainly carried out in a temperature range indicated by a thick black concentric ring, so that the coal bed is called a chemical reaction zone; in the temperature range indicated by the thin black concentric circles, the low-temperature oxidation of coal is mainly based on chemical adsorption and has local chemical reaction, so the coal is called as a chemical adsorption and local chemical reaction zone; the temperature range indicated by the concentric circles with black dashed lines, in which the low temperature oxidation of coal predominates, is therefore referred to as the "physisorption zone". Each zone has a specific function of consuming or retaining oxygen, as described in detail below:
■ in the chemical reaction area, the physical adsorption between coal and oxygen is quickly converted into chemical adsorption, the chemical adsorption is quickly converted into chemical reaction, the chemical reaction heat and the heat brought by the high temperature air together maintain the limited automatic acceleration of the chemical reaction in the area, the limited automatic acceleration is said because the amount of the high temperature air injected into the coal bed is limited, the carried oxygen is limited, the coal oxidation reaction cannot be automatically accelerated to the uncontrollable and burning stage, but the oxygen concentration decreases with the increasing distance from the gas injection well to the periphery, the automatic acceleration rate of the coal oxidation reaction is quickly reduced to zero, the heat generated in the stable oxidation reaction process is equal to the heat lost, because the underground coal bed is a closed system, although the gas injection well and the production well create several singularities on the closed system, the closure of the closed system of the underground coal bed is not changed basically, therefore, the heat lost can effectively expand the range of the chemical reaction area with the initial injection of the high temperature air, the oxygen consumption range is limited, the oxygen consumption range is extended with the chemical reaction area, and the oxygen consumption range is increased gradually to 1 year after the gas injection area.
■ in the chemisorption and local chemisorption reaction zones, not only is the conversion of coal-oxygen physisorption to chemisorption extended, but the conversion of chemisorption to chemical reaction is slow and limited to those active structures in the coal seam that require only low temperatures to effect chemical reactions, such local chemical reactions result from the strong selectivity of chemisorption itself.
■ the amount of oxygen consumed and retained in the physisorption zone is much larger than the sum of oxygen consumption of the chemical reaction zone and the chemical adsorption and local chemical reaction zone, mainly because of three reasons, namely (1) the physical adsorption zone has large space capacity, the coal seam can become the chemical reaction zone, the chemical adsorption and local chemical reaction zone only when reaching a certain temperature, and before that, the physical adsorption zone, although the chemical reaction zone, the chemical adsorption and local chemical reaction zone are rapidly expanded along with the prolonging of the gas injection time, the amount of air injected into the coal seam is small, the gas heat capacity is small, and the direct heating of the coal seam by high-temperature air is a slow and gradual process, while under the condition of increasing the coal seam gas by injecting high-temperature air, the oxygen supply is limited, the chemical reaction heat contributes to the increasing of the coal seam temperature, the slow and gradual process, and for economic benefit, the gas injection well spacing is usually larger than 1000m, therefore, even after several years, the space capacity of the physical adsorption zone is much larger than the sum of the space capacity of the chemical reaction zone and the chemical adsorption and local chemical reaction zone (2) the oxygen consumption of the coal seam is assumed to be 1000m, and the gas injection thickness is 6m,coal density 1.4 ton/m3Then, the mass of coal in the cylindrical space affected by one gas injection well is equal to π 50026 x 1.4 t 6594000 tons; assuming the capacity of the gas injection supercharger to be 1000m3Hour, then, the amount of oxygen injected into the coal bed is equal to about 5040m per day3(ii) a It is continuously assumed that the saturated oxygen uptake of coal is 5.0m3And/ton, then 17.9 years is needed to saturate the amount of absorbed coal in the cylindrical space with a radius of 500m centered in the gas injection well, without considering the oxygen consumption of chemisorption and chemical reaction at all. (3) As discussed above, the physisorption zone is a leaky oxygen reservoir, since physisorption-chemisorption-oxidation-process eventually consumes physisorbed oxygen. As long as the time is long enough, both physical adsorption and chemical adsorption are the preparation and the prelude of the oxidation reaction, and the oxygen adsorbed on the surface of the coal micropores and fissures is finally consumed by the oxidation reaction. In other words, by correctly using the method for increasing the coal bed gas by injecting the high-temperature air provided by the invention, the oxygen absorption of the coal bed gas reservoir can never reach saturation. Therefore, the physical adsorption area is the last and most reliable guarantee for injecting high-temperature air to increase the yield of coal bed gas, and ensures that no excessive oxygen reaches a production well.
After the theoretical basis, the technical points and the difficulties of increasing the coal bed methane by injecting the high-temperature air are discussed in detail, the method for increasing the coal bed methane by injecting the high-temperature air provided by the invention is summarized as follows:
the invention is realized by adopting the following technical means:
the invention relates to a method for increasing coal bed methane by injecting high-temperature air into a coal bed methane reservoir. In particular, the invention relates to a method for injecting high-temperature air into a coal seam from one or more wells communicated with the coal seam, wherein nitrogen in the high-temperature air "strips" and "drives" coal-bed methane in an adsorption state on the micropore and fissure surfaces, the desorption of the coal-bed methane is promoted, the coal-bed methane is transported to a production well, oxygen in the coal-bed methane is retained in the coal seam or consumed due to physical adsorption, chemical adsorption and oxidation reaction due to low-temperature oxidation, and the produced coal-bed methane and mixed gas of the coal-bed methane and the nitrogen are collected from the one or more wells communicated with the coal seam, so that the yield of a coal-bed gas well and the recovery rate of the coal.
The specific implementation steps and characteristics of the method for increasing the coal bed gas by injecting the high-temperature air are as follows:
(a) determining the initial temperature, the heating rate, the normal operation temperature and the accelerated oxygen consumption temperature of air injected into the coal bed according to the characteristics of the coal bed gas reservoir;
(b) starting gas injection operation according to the initial temperature and the heating rate at the gas injection starting stage until the gas injection temperature reaches the normal operation temperature, and entering the normal gas injection yield increasing operation stage;
(c) monitoring the bottom pressure and temperature of the gas injection well, and monitoring the gas composition, the bottom pressure and temperature, the top pressure and temperature of the production well;
(d) when the moisture content in the gas of the production well is obviously reduced, a water injection high-pressure switch in a gas injection well mouth or a gas injection pipeline is opened, and the water injection high-pressure switch of the gas injection well mouth is closed until the moisture content in the gas of the production well is recovered to be normal;
(e) when the oxygen content in the gas of the production well is abnormally increased or the oxygen content in the gas of the production well exceeds the standard specified by the coal bed gas production specification, raising the gas injection temperature to the accelerated oxygen consumption temperature, and reducing the gas injection temperature to the normal operation temperature until the oxygen content in the gas of the production well is recovered to be normal;
(f) determining the highest allowable gas temperature of the production well according to the characteristics of the coal bed gas reservoir and the performance of the coal bed gas post-processing equipment;
(g) when the gas temperature of the production well is increased to be close to the highest allowable temperature, stopping gas injection operation until the bottom hole pressure of the production well is reduced to be close to the hydrostatic pressure of a coal bed gas reservoir or until the gas yield of the production well is reduced to be close to an economic threshold value, starting gas injection operation according to the initial temperature and the temperature rise rate according to the operation program of the gas injection starting stage until the gas injection temperature reaches the normal operation temperature, and entering the normal gas injection yield-increasing operation stage again;
(h) when the gas temperature of the production well is increased to be close to the maximum allowable temperature and the temperature reduction effect of the step (g) is poor or the step (g) cannot be implemented due to the poor temperature reduction effect, injecting normal-temperature air or normal-temperature nitrogen again until the gas temperature of the production well is sufficiently reduced, starting gas injection operation according to the initial temperature and the temperature increase rate according to the operation program of the gas injection starting stage until the gas injection temperature reaches the normal operation temperature, and entering the normal gas injection yield-increasing operation stage again;
(i) steps (d), (e), (g) and (h) may be repeated as many times as necessary.
Finally, it should be noted that although the present invention has been described in detail herein, it will be understood by those skilled in the art that the present invention may be modified and equivalents may be substituted; all such modifications and variations that do not depart from the spirit and scope of the invention are intended to be included within the scope of the appended claims.
Claims (12)
- A method for injecting high-temperature air into a coal bed from one or more gas injection wells communicated with a coal bed gas reservoir, wherein nitrogen in the high-temperature air is stripped and drives off adsorbed coal bed gas on the surfaces of coal micropores and cracks to promote the desorption of the coal bed gas and move the coal bed gas to a production well, the oxygen in the high-temperature air is retained in the coal bed or consumed due to physical adsorption, chemical adsorption and oxidation reaction due to low-temperature oxidation, and the produced coal bed gas and mixed gas of the coal bed gas and the nitrogen are collected from a plurality of production wells communicated with the coal bed, so that the yield of a gas well and the recovery rate of the coal bed gas are improved, and is characterized by comprising the following steps of:(a) determining the initial temperature, the heating rate, the normal operation temperature and the accelerated oxygen consumption temperature of air injected into the coal bed according to the characteristics of the coal bed gas reservoir;(b) starting gas injection operation according to the initial temperature and the heating rate at the gas injection starting stage until the gas injection temperature reaches the normal operation temperature, and entering the normal gas injection yield increasing operation stage;(c) monitoring the bottom pressure and temperature of the gas injection well, and monitoring the gas composition, the bottom pressure and temperature, the top pressure and temperature of the production well;(d) when the moisture content in the gas of the production well is obviously reduced, a water injection high-pressure switch in a gas injection well mouth or a gas injection pipeline is opened, and the water injection high-pressure switch of the gas injection well mouth is closed until the moisture content in the gas of the production well is recovered to be normal;(e) when the oxygen content in the gas of the production well is abnormally increased or the oxygen content in the gas of the production well exceeds the standard specified by the coal bed gas production specification, raising the gas injection temperature to the accelerated oxygen consumption temperature, and reducing the gas injection temperature to the normal operation temperature until the oxygen content in the gas of the production well is recovered to be normal;(f) determining the highest allowable gas temperature of the production well according to the characteristics of the coal bed gas reservoir and the performance of the coal bed gas post-processing equipment;(g) when the gas temperature of the production well is increased to be close to the highest allowable temperature, stopping gas injection operation until the bottom hole pressure of the production well is reduced to be close to the hydrostatic pressure of a coal bed gas reservoir or until the gas yield of the production well is reduced to be close to an economic threshold value, starting gas injection operation according to the initial temperature and the temperature rise rate according to the operation program of the gas injection starting stage until the gas injection temperature reaches the normal operation temperature, and entering the normal gas injection yield-increasing operation stage again;(h) when the gas temperature of the production well is increased to be close to the maximum allowable temperature and the temperature reduction effect of the step (g) is poor or the step (g) cannot be implemented due to the poor temperature reduction effect, injecting normal-temperature air or normal-temperature nitrogen again until the gas temperature of the production well is sufficiently reduced, starting gas injection operation according to the initial temperature and the temperature increase rate according to the operation program of the gas injection starting stage until the gas injection temperature reaches the normal operation temperature, and entering the normal gas injection yield-increasing operation stage again;(i) steps (d), (e), (g) and (h) may be repeated as many times as necessary.
- The method of claim 1, wherein the injected coal bed is air.
- The method of claim 1, wherein the temperature of the air injected into the coal seam is higher than ambient temperature.
- The method of claim 1, wherein the initial temperature, the heating rate, the normal operating temperature, and the accelerated oxygen consumption temperature are set to ensure safe gas injection and to ensure that oxygen is retained in the coal seam or consumed in the coal seam gas.
- The method of claim 1, wherein said initial temperature is selected from the range of ambient temperature to 70 ℃, wherein said rate of temperature increase is selected from the range of 20 ℃/day to 10 ℃/month, wherein said normal operating temperature is selected from the range of about three thousandths of the coal ignition temperature of the coal seam being injected, and wherein said accelerated oxygen consumption temperature is selected from the range of about four thousandths of the coal ignition temperature of the coal seam being injected.
- The method of claim 1, wherein the initial temperature, the rate of temperature rise, the normal operating temperature, and the accelerated oxygen consumption temperature are selected based on laboratory measurements of the low temperature oxidation oxygen consumption of the coal seam sample as a function of temperature.
- The method of claim 1, wherein the initial temperature, the ramp rate, the normal operating temperature, and the accelerated oxygen depletion temperature are selected and determined taking into account a plurality of characteristics of the coalbed methane reservoir and adjusted as necessary to cause changes in the characteristics of the coalbed methane reservoir as the time for injecting the high temperature air is extended.
- The method of claim 1, wherein the moisture is added to the gas injection pipeline to catalyze the reaction between the coal and oxygen.
- The method of claim 1, wherein the injection temperature is increased to enhance the chemical reaction between the coal and oxygen and increase the oxygen consumption when the oxygen content in the gas from the production well is higher than expected.
- The method of claim 1, wherein when the gas temperature in the production well rises above the desired temperature, the gas injection is stopped, or normal temperature air is injected, or normal temperature nitrogen is injected, so as to directly lower the temperature of the coal bed, and the chemical reaction between the coal and oxygen is weakened, thereby reducing the heating effect of the chemical reaction heat on the coal bed.
- The method of claim 1, wherein the high temperature air is obtained by adjusting a final cooler of the booster using a booster whose final cooler is adjustable, or by heating high pressure air output from the booster using a temperature adjustable duct gas heater, or by heating high pressure air output from the booster using both the final cooler adjustable booster and the temperature adjustable duct gas heater, or by heating high pressure air output from the booster using any other means.
- The method of claim 1, wherein the production well gas has a maximum allowable temperature, and wherein the temperature of the coalbed methane reservoir in situ in the ground prior to injecting the high temperature air is selected to be determined between the temperature of the coalbed methane reservoir in situ in the ground and the allowable temperature of the coalbed methane post-treatment equipment.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/CN2017/077861 WO2018170830A1 (en) | 2017-03-23 | 2017-03-23 | Method for increasing production of coal bed gas by injecting high temperature air |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110972485A true CN110972485A (en) | 2020-04-07 |
| CN110972485B CN110972485B (en) | 2022-08-12 |
Family
ID=63586149
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201780088693.6A Active CN110972485B (en) | 2017-03-23 | 2017-03-23 | Method for increasing production of coal bed gas by injecting high-temperature air |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN110972485B (en) |
| WO (1) | WO2018170830A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115217443A (en) * | 2021-04-19 | 2022-10-21 | 中国石油天然气股份有限公司 | Nitrogen injection yield increasing method |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109798095A (en) * | 2019-03-08 | 2019-05-24 | 南阳市天达同兴石油技术有限公司 | A kind of coal-bed-gas production-increase pressure disturbance device and method for increasing yield of coal bed gas |
| CN113803048A (en) * | 2021-08-11 | 2021-12-17 | 太原理工大学 | Coal in-situ separation mining method based on pyrolysis |
| CN114109340A (en) * | 2021-09-24 | 2022-03-01 | 陕西省煤田地质集团有限公司 | Underground in-situ compensation heating fluid injection pyrolysis oil extraction well structure of coal bed and oil extraction method |
| CN114592829A (en) * | 2022-03-04 | 2022-06-07 | 中煤科工集团重庆研究院有限公司 | Gas injection displacement enhanced gas extraction method |
| CN114718534B (en) * | 2022-04-21 | 2023-09-08 | 陕西省煤田地质集团有限公司 | In-situ pyrolysis system for coupling self-heating and electric heating of oil-rich coal |
| CN115931949B (en) * | 2022-10-11 | 2024-03-22 | 中国矿业大学 | Method for quantitatively evaluating gas injection to improve coalbed methane recovery ratio |
Citations (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3734184A (en) * | 1971-06-18 | 1973-05-22 | Cities Service Oil Co | Method of in situ coal gasification |
| US5332036A (en) * | 1992-05-15 | 1994-07-26 | The Boc Group, Inc. | Method of recovery of natural gases from underground coal formations |
| WO1995012746A1 (en) * | 1993-11-03 | 1995-05-11 | Amoco Corporation | Method for the recovery of coal bed methane |
| CN1932237A (en) * | 2005-04-27 | 2007-03-21 | 钻石Qc技术公司 | Flue gas injection for heavy oil recovery |
| CN101092879A (en) * | 2007-07-26 | 2007-12-26 | 康怀宇 | Method for injecting retarder to coal body |
| CN101268250A (en) * | 2005-09-21 | 2008-09-17 | 国际壳牌研究有限公司 | Method of producing a hydrocarbon stream from a subterranean zone |
| CN101382061A (en) * | 2007-09-07 | 2009-03-11 | 新奥科技发展有限公司 | Novel coalbed gas thermal recovery process |
| CN101988384A (en) * | 2010-08-31 | 2011-03-23 | 新奥科技发展有限公司 | Method for in-situ retorting of underground coal bed by utilizing flue gas |
| CN102162352A (en) * | 2011-04-19 | 2011-08-24 | 王正东 | Novel method for exploiting coal-bed gas |
| CN102465692A (en) * | 2010-10-29 | 2012-05-23 | 新奥科技发展有限公司 | Method for obtaining fuel air region shape in real time in coal underground gasification process |
| CN102913222A (en) * | 2012-11-20 | 2013-02-06 | 中国石油集团长城钻探工程有限公司工程服务公司 | Oxidation process completion method of horizontal well for developing coalbed methane |
| CN103061730A (en) * | 2013-01-28 | 2013-04-24 | 中国石油大学(华东) | Method for coal bed methane mining by multi-element thermal fluid foam displacement |
| CN103122759A (en) * | 2013-01-28 | 2013-05-29 | 中国石油大学(华东) | Coal bed gas well multiple thermal fluid strengthening mining method |
| CN104234740A (en) * | 2014-09-03 | 2014-12-24 | 太原理工大学 | Low-medium pressure air displacement high-pressure coalbed gas system and method thereof |
| CN105138029A (en) * | 2015-08-03 | 2015-12-09 | 陈信平 | Program and method for controlling pressure of nitrogen injection production increase coal bed gas |
| US20160123128A1 (en) * | 2013-06-26 | 2016-05-05 | ENN Coal Gasification Mining Co., Ltd. | Gas injection apparatus with controllable gas injection point, gas injection process, and gasification method |
| RU2602094C1 (en) * | 2015-07-31 | 2016-11-10 | Анатолий Фёдорович Косолапов | Method of thermal oil production |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4114688A (en) * | 1977-12-05 | 1978-09-19 | In Situ Technology Inc. | Minimizing environmental effects in production and use of coal |
| RU2287056C1 (en) * | 2005-05-17 | 2006-11-10 | Московский государственный горный университет (МГГУ) | Method for electric power generation in situ |
| CN105063093A (en) * | 2015-08-07 | 2015-11-18 | 河南理工大学 | Method for preparation of coalbed methane from microorganisms |
-
2017
- 2017-03-23 CN CN201780088693.6A patent/CN110972485B/en active Active
- 2017-03-23 WO PCT/CN2017/077861 patent/WO2018170830A1/en active Application Filing
Patent Citations (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3734184A (en) * | 1971-06-18 | 1973-05-22 | Cities Service Oil Co | Method of in situ coal gasification |
| US5332036A (en) * | 1992-05-15 | 1994-07-26 | The Boc Group, Inc. | Method of recovery of natural gases from underground coal formations |
| WO1995012746A1 (en) * | 1993-11-03 | 1995-05-11 | Amoco Corporation | Method for the recovery of coal bed methane |
| CN1932237A (en) * | 2005-04-27 | 2007-03-21 | 钻石Qc技术公司 | Flue gas injection for heavy oil recovery |
| CN101268250A (en) * | 2005-09-21 | 2008-09-17 | 国际壳牌研究有限公司 | Method of producing a hydrocarbon stream from a subterranean zone |
| CN101092879A (en) * | 2007-07-26 | 2007-12-26 | 康怀宇 | Method for injecting retarder to coal body |
| CN101382061A (en) * | 2007-09-07 | 2009-03-11 | 新奥科技发展有限公司 | Novel coalbed gas thermal recovery process |
| CN101988384A (en) * | 2010-08-31 | 2011-03-23 | 新奥科技发展有限公司 | Method for in-situ retorting of underground coal bed by utilizing flue gas |
| CN102465692A (en) * | 2010-10-29 | 2012-05-23 | 新奥科技发展有限公司 | Method for obtaining fuel air region shape in real time in coal underground gasification process |
| CN102162352A (en) * | 2011-04-19 | 2011-08-24 | 王正东 | Novel method for exploiting coal-bed gas |
| CN102913222A (en) * | 2012-11-20 | 2013-02-06 | 中国石油集团长城钻探工程有限公司工程服务公司 | Oxidation process completion method of horizontal well for developing coalbed methane |
| CN103061730A (en) * | 2013-01-28 | 2013-04-24 | 中国石油大学(华东) | Method for coal bed methane mining by multi-element thermal fluid foam displacement |
| CN103122759A (en) * | 2013-01-28 | 2013-05-29 | 中国石油大学(华东) | Coal bed gas well multiple thermal fluid strengthening mining method |
| US20160123128A1 (en) * | 2013-06-26 | 2016-05-05 | ENN Coal Gasification Mining Co., Ltd. | Gas injection apparatus with controllable gas injection point, gas injection process, and gasification method |
| CN104234740A (en) * | 2014-09-03 | 2014-12-24 | 太原理工大学 | Low-medium pressure air displacement high-pressure coalbed gas system and method thereof |
| RU2602094C1 (en) * | 2015-07-31 | 2016-11-10 | Анатолий Фёдорович Косолапов | Method of thermal oil production |
| CN105138029A (en) * | 2015-08-03 | 2015-12-09 | 陈信平 | Program and method for controlling pressure of nitrogen injection production increase coal bed gas |
Non-Patent Citations (8)
| Title |
|---|
| 宋万新等: "含瓦斯风流条件下煤自燃产物CO生成规律的实验研究", 《煤炭学报》 * |
| 宋万新等: "含瓦斯风流条件下煤自燃产物CO生成规律的实验研究", 《煤炭学报》, vol. 37, no. 8, 15 August 2012 (2012-08-15), pages 1320 - 1325 * |
| 杨宏民: "井下注气驱替煤层甲烷机理及规律研究", 《中国博士学位论文全文数据库 工程科学I辑》 * |
| 杨宏民: "井下注气驱替煤层甲烷机理及规律研究", 《中国博士学位论文全文数据库 工程科学I辑》, no. 01, 15 January 2011 (2011-01-15), pages 76 - 86 * |
| 郝定溢等: "我国注气驱替煤层瓦斯技术应用现状与展望", 《中国矿业》 * |
| 郝定溢等: "我国注气驱替煤层瓦斯技术应用现状与展望", 《中国矿业》, vol. 25, no. 7, 15 July 2016 (2016-07-15), pages 77 - 81 * |
| 陈信平等: "以预测为指导的中国煤层气勘探开发技术模式探讨", 《中国海上油气》 * |
| 陈信平等: "以预测为指导的中国煤层气勘探开发技术模式探讨", 《中国海上油气》, vol. 25, no. 5, 15 October 2013 (2013-10-15), pages 31 - 34 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115217443A (en) * | 2021-04-19 | 2022-10-21 | 中国石油天然气股份有限公司 | Nitrogen injection yield increasing method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110972485B (en) | 2022-08-12 |
| WO2018170830A1 (en) | 2018-09-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110972485A (en) | Method for increasing production of coal bed gas by injecting high-temperature air | |
| Raza et al. | Significant aspects of carbon capture and storage–A review | |
| Kędzior | Accumulation of coal-bed methane in the south-west part of the Upper Silesian Coal Basin (southern Poland) | |
| Goraya et al. | Coal bed methane enhancement techniques: a review | |
| Abba et al. | Solubility trapping as a potential secondary mechanism for CO2 sequestration during enhanced gas recovery by CO2 injection in conventional natural gas reservoirs: An experimental approach | |
| Luo et al. | Effect of reactive surface area of minerals on mineralization trapping of CO 2 in saline aquifers | |
| EA021444B1 (en) | Process for generating hydrogen | |
| Fulton et al. | A laboratory investigation of enhanced recovery of methane from coal by carbon dioxide injection | |
| Almenningen et al. | Experimental Investigation of Critical Parameters Controlling CH4–CO2 Exchange in Sedimentary CH4 Hydrates | |
| Nguyen | Carbon dioxide geological sequestration: Technical and economic reviews | |
| Liu et al. | Quantitative study of CO2 huff-n-puff enhanced oil recovery in tight formation using online NMR technology | |
| Thakur et al. | Coal bed methane: theory and applications | |
| Hasan et al. | Enhanced gas recovery (EGR) methods and production enhancement techniques for shale & tight gas reservoirs | |
| Drizhd et al. | Coal bed methane of Karaganda basin in the gas balance of the Republic of Kazakhstan: Status and prospects | |
| Jiang et al. | China's CCUS progresses and a new evaluation method of CO2 storage capacity in coalbed reservoirs | |
| Zareei et al. | Petrophysical changes of carbonate rock related to CO2 injection and sequestration | |
| WO2012118410A2 (en) | Method of carbon dioxide disposal in water-bearing strata | |
| Etiope | Natural gas | |
| Anggara et al. | Mineral dissolution/precipitation during CO2 injection into coal reservoir: a laboratory study | |
| Meier et al. | Using stable carbon isotopes to track potential leakage of carbon dioxide: Example from an enhanced coal bed methane recovery site in West Virginia, USA | |
| Mwakipunda et al. | Recent Advances in Carbon Dioxide Sequestration in Deep Unmineable Coal Seams Using CO2-ECBM Technology: Experimental Studies, Simulation, and Field Applications | |
| Van Wageningen et al. | Reservoir simulation and interpretation of the RECOPOL ECBM pilot in Poland | |
| Kumar et al. | Carbon capture and sequestration technology for environmental remediation: A CO2 utilization approach through EOR | |
| Qin et al. | Multi-Component Thermal Fluid Injection Performance in Recovery of Heavy Oil Reservoirs | |
| Chen et al. | Assessing the potential for CO2 storage in shallow coal seams using gas geochemistry: A case study from Qinshui Basin, North China |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20231106 Address after: 010000 Room 201, Unit 3, Building 15, Jinyu Ziguang Community, Xing'an South Road, Saihan District, Hohhot City, Inner Mongolia Autonomous Region Patentee after: Xin Weidong Address before: Room 1921, 16th Floor, Building 3, Yard 9, Huilongguan West Street, Changping District, Beijing 102208 Patentee before: Beijing Jiemaodi China Energy Technology Co.,Ltd. |
|
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20231122 Address after: 010000 No. 005, 15th Floor, Jintiandi Building, No. 6 Zhongshan East Road, Xincheng District, Hohhot, Inner Mongolia Autonomous Region Patentee after: Inner Mongolia Zhongkuang Clean Coal Technology Co.,Ltd. Address before: 010000 Room 201, Unit 3, Building 15, Jinyu Ziguang Community, Xing'an South Road, Saihan District, Hohhot City, Inner Mongolia Autonomous Region Patentee before: Xin Weidong |
|
| TR01 | Transfer of patent right |