Coal fracturing under dynamic load induced by methane deflagration
Abstract To elucidate the dynamic characteristics of in-situ methane deflagration in coalbed methane wellbores and its mechanisms for fracturing coal rock, this study first developed a simulation experimental system specifically designed for methane in-situ deflagration fracturing. This experimental...
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| Format: | Article |
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SpringerOpen
2025-07-01
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| Series: | International Journal of Coal Science & Technology |
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| Online Access: | https://doi.org/10.1007/s40789-025-00794-1 |
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| author | Ting Liu Jiabin Hu Yu Wang Cheng Zhai Jianfeng Li Xiangguo Kong Zhongqiu Liang |
| author_facet | Ting Liu Jiabin Hu Yu Wang Cheng Zhai Jianfeng Li Xiangguo Kong Zhongqiu Liang |
| author_sort | Ting Liu |
| collection | DOAJ |
| description | Abstract To elucidate the dynamic characteristics of in-situ methane deflagration in coalbed methane wellbores and its mechanisms for fracturing coal rock, this study first developed a simulation experimental system specifically designed for methane in-situ deflagration fracturing. This experimental system, which is capable of withstanding pressures up to 150 MPa and meanwhile applying axial and confining pressures of up to 50 MPa to rock cores, enables the coupled simulation on methane deflagration and rock core fracturing processes. With the aid of this experimental system, physical simulation experiments on in-situ methane deflagration fracturing were conducted, and the following findings were obtained. Methane deflagration loads in enclosed wellbores exhibit characteristics of multi-level pulsed oscillation. With the rise of initial gas pressure, the peak deflagration load increases approximately linearly, with the pressure amplification factor spanning from 23.14 to 31.10, and its peak loading rate grows exponentially. Accordingly, the fracture volume and fracture porosity augment. To be specific, when the initial gas pressure rises from 0.6 to 2.4 MPa, the fracture volume and fracture porosity augment by factors of 14.0 and 8.73, respectively. The fractal dimension of spatial distribution of fractures also increases with the rise of deflagration load, indicating that a higher deflagration load conduces to the development of a larger and more complex fracture network. Methane deflagration fracturing is characterized as a composite fracture mode that involves the impact of strong stress waves and the driving force of high-pressure fluids. The primary factors influencing damage to coal-rock include the high-stress impact in the initial stage of deflagration, the fluid pressure driving effect in the middle stage, and the thermal shock resulting from high temperatures in the later stage. |
| format | Article |
| id | doaj-art-eeec85b00a154ef393af4321feadf609 |
| institution | DOAJ |
| issn | 2095-8293 2198-7823 |
| language | English |
| publishDate | 2025-07-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | International Journal of Coal Science & Technology |
| spelling | doaj-art-eeec85b00a154ef393af4321feadf6092025-08-20T03:03:19ZengSpringerOpenInternational Journal of Coal Science & Technology2095-82932198-78232025-07-0112111910.1007/s40789-025-00794-1Coal fracturing under dynamic load induced by methane deflagrationTing Liu0Jiabin Hu1Yu Wang2Cheng Zhai3Jianfeng Li4Xiangguo Kong5Zhongqiu Liang6State Key Laboratory of Coal Mine Disaster Prevention and ControlState Key Laboratory of Coal Mine Disaster Prevention and ControlState Key Laboratory of Coal Mine Disaster Prevention and ControlState Key Laboratory of Coal Mine Disaster Prevention and ControlXuzhou Coal Mining GroupCollege of Safety Science and Engineering, Xi’an University of Science and TechnologyCCTEG Shenyang Research InstituteAbstract To elucidate the dynamic characteristics of in-situ methane deflagration in coalbed methane wellbores and its mechanisms for fracturing coal rock, this study first developed a simulation experimental system specifically designed for methane in-situ deflagration fracturing. This experimental system, which is capable of withstanding pressures up to 150 MPa and meanwhile applying axial and confining pressures of up to 50 MPa to rock cores, enables the coupled simulation on methane deflagration and rock core fracturing processes. With the aid of this experimental system, physical simulation experiments on in-situ methane deflagration fracturing were conducted, and the following findings were obtained. Methane deflagration loads in enclosed wellbores exhibit characteristics of multi-level pulsed oscillation. With the rise of initial gas pressure, the peak deflagration load increases approximately linearly, with the pressure amplification factor spanning from 23.14 to 31.10, and its peak loading rate grows exponentially. Accordingly, the fracture volume and fracture porosity augment. To be specific, when the initial gas pressure rises from 0.6 to 2.4 MPa, the fracture volume and fracture porosity augment by factors of 14.0 and 8.73, respectively. The fractal dimension of spatial distribution of fractures also increases with the rise of deflagration load, indicating that a higher deflagration load conduces to the development of a larger and more complex fracture network. Methane deflagration fracturing is characterized as a composite fracture mode that involves the impact of strong stress waves and the driving force of high-pressure fluids. The primary factors influencing damage to coal-rock include the high-stress impact in the initial stage of deflagration, the fluid pressure driving effect in the middle stage, and the thermal shock resulting from high temperatures in the later stage.https://doi.org/10.1007/s40789-025-00794-1Deflagration fracturingDynamic loadHigh temperature and high pressureFracture propagationRock fracturing mode |
| spellingShingle | Ting Liu Jiabin Hu Yu Wang Cheng Zhai Jianfeng Li Xiangguo Kong Zhongqiu Liang Coal fracturing under dynamic load induced by methane deflagration International Journal of Coal Science & Technology Deflagration fracturing Dynamic load High temperature and high pressure Fracture propagation Rock fracturing mode |
| title | Coal fracturing under dynamic load induced by methane deflagration |
| title_full | Coal fracturing under dynamic load induced by methane deflagration |
| title_fullStr | Coal fracturing under dynamic load induced by methane deflagration |
| title_full_unstemmed | Coal fracturing under dynamic load induced by methane deflagration |
| title_short | Coal fracturing under dynamic load induced by methane deflagration |
| title_sort | coal fracturing under dynamic load induced by methane deflagration |
| topic | Deflagration fracturing Dynamic load High temperature and high pressure Fracture propagation Rock fracturing mode |
| url | https://doi.org/10.1007/s40789-025-00794-1 |
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