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公开(公告)号:US10378327B2
公开(公告)日:2019-08-13
申请号:US15321891
申请日:2015-12-22
Applicant: CHINA UNIVERSITY OF MINING AND TECHNOLOGY
Inventor: Baiquan Lin , Quanle Zou , Ting Liu , Chang Guo , Chuanjie Zhu , Jia Kong , Fazhi Yan , Hao Yao , Yidou Hong
IPC: E21B36/00 , E21B43/24 , E21B43/267 , E21F7/00 , E21B43/114
Abstract: A gas extraction method in which high energy gas fracturing technology is used to form a fracture network in a thermal injection borehole. Then high-pressure, cyclically temperature-changing steam is injected into the borehole using a spinning oscillating-pulse jet nozzle to form oscillating superheated steam, alternatingly impacting and heating the coal body. The high energy gas forms a fracture network that provides channels for passage of the superheated steam, while oscillating changes in steam temperature and pressure also promote crack propagation and perforation of the coal body; the combined effect of alternation of the two enhances gas desorption and extraction efficiency.
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公开(公告)号:US10858913B2
公开(公告)日:2020-12-08
申请号:US15767880
申请日:2016-12-15
Applicant: CHINA UNIVERSITY OF MINING AND TECHNOLOGY
Inventor: Bai quan Lin , Fazhi Yan , Xiangliang Zhang , Jia Kong , Ting Liu , Chuanjie Zhu
Abstract: A permeability enhancement method for coalbed methane wells by using electric pulse detonation fracturing technology is applicable to exploitation of coalbed methane wells in coal beds with low permeability. Firstly, a positive electrode coalbed methane wellbore and a negative electrode coalbed methane wellbore are constructed from the ground surface to a coal bed. A fixed platform installed with a positive electrode and a high-voltage pulse device are placed, by using a derrick, downwards to a predetermined permeability enhancement portion of the coal bed in the positive electrode coalbed methane wellbore, and another fixed platform installed with a negative electrode is placed, by using a derrick, downwards to a predetermined permeability enhancement portion of the coal bed in the negative electrode coalbed methane wellbore. The coal bed between the positive electrode and the negative electrode is broken down by using a high voltage, and coalbed methane extraction is carried out in the positive electrode coalbed methane wellbore and the negative electrode coalbed methane wellbore. A large amount of energy produced by high-voltage electric pulse directly acts on the coal reservoir to form a plasma channel in the coal bed between the positive electrode and the negative electrode. The large amount of energy instantly passes through the plasma channel, and the produced high-temperature thermal expansion force and shock waves act on the coal bed, such that the number of cracks in the coal bed is effectively increased and a favorable condition is created for flowing of coalbed methane.
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公开(公告)号:US10060238B2
公开(公告)日:2018-08-28
申请号:US15322457
申请日:2015-12-22
Applicant: CHINA UNIVERSITY OF MINING AND TECHNOLOGY
Inventor: Baiquan Lin , Chang Guo , Quanle Zou , Ting Liu , Chuanjie Zhu , Jia Kong , Fazhi Yan , Hao Yao , Yidu Hong
CPC classification number: E21B43/24 , E21B7/18 , E21B41/0078 , E21B43/26 , E21F7/00
Abstract: A method for combining integrated drilling and slotting with oscillating thermal injection to enhance coalbed gas extraction, applicable to managing gas extraction from microporous, low-permeability, high-adsorption coal seam areas. A number of slots are formed within a thermal injection/extraction borehole by means of integrated drilling and slotting technology; a steam generator, is then used to three high-pressure, cyclically temperature-changing steam into said borehole; the steam passing through a spinning, oscillating-pulse jet nozzle forms an oscillating superheated steam, heating the coal body. The present method overcomes the limitations of simple permeability-increasing techniques, the slotting by means of hydraulic. pressure significantly increasing the pressure relief range of a single borehole and forming a fracture network that provides channels for passage of the superheated steam, while oscillating variation in steam temperature and pressure also promote crack propagation and perforation of the coal body; the combined effect of the two enhances the efficiency of gas desorption and extraction.
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4.
公开(公告)号:US20180209259A1
公开(公告)日:2018-07-26
申请号:US15321891
申请日:2015-12-22
Applicant: CHINA UNIVERSITY OF MINING AND TECHNOLOGY
Inventor: Baiquan LIN , Quanle Zou , Ting Liu , Chang Guo , Chuanjie Zhu , Jia Kong , Fazhi Yan , Hao Yao , Yidou Hong
IPC: E21B43/267 , E21B43/24 , E21F7/00 , E21B36/00
CPC classification number: E21B43/267 , E21B36/006 , E21B43/114 , E21B43/2405 , E21F7/00
Abstract: A gas extraction method in which high energy gas fracturing technology is used to form a fracture network in a thermal injection borehole. Then high-pressure, cyclically temperature-changing steam is injected into the borehole using a spinning oscillating-pulse jet nozzle to form oscillating superheated steam, alternatingly impacting and heating the coal body. The high energy gas forms a fracture network that provides channels for passage of the superheated steam, while oscillating changes in steam temperature and pressure also promote crack propagation and perforation of the coal body; the combined effect of alternation of the two enhances gas desorption and extraction efficiency.
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5.
公开(公告)号:US10370942B2
公开(公告)日:2019-08-06
申请号:US15325506
申请日:2015-12-21
Applicant: China University of Mining and Technology
Inventor: Baiquan Lin , Ting Liu , Quanle Zou , Chang Guo , Chuanjie Zhu , Hao Yao , Fazhi Yan , Jia Kong , Yidu Hong
Abstract: A method for combining integrated drilling, flushing and slotting with thermal injection to enhance coalbed gas extraction, applicable to managing gas extraction from microporous, low-permeability, high-adsorption coalbed areas. A gas extraction borehole is drilled within a certain distance of a predetermined drilling, flushing and slotting borehole, and, once sealed, is used for gas extraction. An integrated drilling, flushing and slotting drill bit is used to sink the borehole, which is then sealed. Concentration variation in the gas extraction borehole is monitored in real time, and when concentration is below 30%, borehole is opened and high-temperature steam is injected by means of a steam generator, after which the borehole is again closed. Drilling a drilling, flushing and slotting borehole increases pressure relief space and the surface of exposed coal, relieves stress on the coal body, and increases gas permeability of the coalbed, while the injection of high-temperature steam promotes gas desorption in the coal body, promotes crack propagation around the borehole, and increases channels for gas flow, thus achieving highly efficient extraction of gas from the coalbed.
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6.
公开(公告)号:US20170145794A1
公开(公告)日:2017-05-25
申请号:US15325506
申请日:2015-12-21
Applicant: China University of Mining and Technology
Inventor: Baiquan Lin , Ting Liu , Quanle Zou , Chang Guo , Chuanjie Zhu , Hao Yao , Fazhi Yan , Jia Kong , Yidu Hong
CPC classification number: E21B43/006 , E21B7/00 , E21B43/24 , E21B43/30 , E21F7/00
Abstract: A method for combining integrated drilling, flushing and slotting with thermal injection to enhance coalbed gas extraction, applicable to managing gas extraction from microporous, low-permeability, high-adsorption coalbed areas. A gas extraction borehole is drilled within a certain distance of a predetermined drilling, flushing and slotting borehole, and, once sealed, is used for gas extraction. An integrated drilling, flushing and slotting drill bit is used to sink the borehole, which is then sealed. Concentration variation in the gas extraction borehole is monitored in real time, and when concentration is below 30%, borehole is opened and high-temperature steam is injected by means of a steam generator, after which the borehole is again closed. Drilling a drilling, flushing and slotting borehole increases pressure relief space and the surface of exposed coal, relieves stress on the coal body, and increases gas permeability of the coalbed, while the injection of high-temperature steam promotes gas desorption in the coal body, promotes crack propagation around the borehole, and increases channels for gas flow, thus achieving highly efficient extraction of gas from the coalbed.
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