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1.发明申请公开(公告)号：US20200240246A1
公开(公告)日：2020-07-30
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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2.发明申请公开(公告)号：US20180209255A1
公开(公告)日：2018-07-26
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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