Numerical Analysis of Heat and Gas Transfer Characteristics during Heat Injection Processes Based on a Thermo-Hydro-Mechanical Model
Heat injection is an important artificial technique, which can significantly enhance the extraction efficiency of coal seam gas (CSG) and reduce the outburst risk caused by CSG. Although heat injection has been comprehensively investigated, the effect of temperature on the coal–gas interac...
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| Format: | Article |
| Language: | English |
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MDPI AG
2018-07-01
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| Series: | Energies |
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| Online Access: | http://www.mdpi.com/1996-1073/11/7/1722 |
| _version_ | 1811303855819849728 |
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| author | Yi Xue Faning Dang Zhengzheng Cao Feng Du Fei Liu Jie Ren Feng Gao |
| author_facet | Yi Xue Faning Dang Zhengzheng Cao Feng Du Fei Liu Jie Ren Feng Gao |
| author_sort | Yi Xue |
| collection | DOAJ |
| description | Heat injection is an important artificial technique, which can significantly enhance the extraction efficiency of coal seam gas (CSG) and reduce the outburst risk caused by CSG. Although heat injection has been comprehensively investigated, the effect of temperature on the coal–gas interactions in CSG extraction is still not clear. In this study, a thermo-hydro-mechanical model was developed considering the expansion of coal mass and the change of adsorption capacity induced by heat injection. Subsequently, the reliability of the model was verified through a comparison with other theoretical models and field data. Finally, a numerical simulation and parameter analysis of the heat injection process were performed and compared with the traditional gas extraction method. The simulation results show that heat injection can significantly increase the gas production rate and cumulative gas production through the gas desorption and the permeability increase. The gas content in the coal seam dramatically decreases in the vicinity of the production and heat injection wells under the condition of heat injection, which greatly accelerates the gas drainage. The coal deformation caused by thermal-induced gas desorption has a more dominant effect on the porosity than other factors, i.e., pore pressure, thermal strain and compressive strain. |
| first_indexed | 2024-04-13T07:55:36Z |
| format | Article |
| id | doaj.art-3c86ea74a22c4a7a861abb3504392397 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-04-13T07:55:36Z |
| publishDate | 2018-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-3c86ea74a22c4a7a861abb35043923972022-12-22T02:55:25ZengMDPI AGEnergies1996-10732018-07-01117172210.3390/en11071722en11071722Numerical Analysis of Heat and Gas Transfer Characteristics during Heat Injection Processes Based on a Thermo-Hydro-Mechanical ModelYi Xue0Faning Dang1Zhengzheng Cao2Feng Du3Fei Liu4Jie Ren5Feng Gao6State Key Laboratory of Eco-hydraulics in Northwest Arid Region, Xi’an University of Technology, Xi’an 710048, ChinaState Key Laboratory of Eco-hydraulics in Northwest Arid Region, Xi’an University of Technology, Xi’an 710048, ChinaSchool of Civil Engineering, Henan Polytechnic University, Jiaozuo 454003, ChinaSchool of Civil Engineering, Henan Polytechnic University, Jiaozuo 454003, ChinaState Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou 221116, ChinaState Key Laboratory of Eco-hydraulics in Northwest Arid Region, Xi’an University of Technology, Xi’an 710048, ChinaState Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou 221116, ChinaHeat injection is an important artificial technique, which can significantly enhance the extraction efficiency of coal seam gas (CSG) and reduce the outburst risk caused by CSG. Although heat injection has been comprehensively investigated, the effect of temperature on the coal–gas interactions in CSG extraction is still not clear. In this study, a thermo-hydro-mechanical model was developed considering the expansion of coal mass and the change of adsorption capacity induced by heat injection. Subsequently, the reliability of the model was verified through a comparison with other theoretical models and field data. Finally, a numerical simulation and parameter analysis of the heat injection process were performed and compared with the traditional gas extraction method. The simulation results show that heat injection can significantly increase the gas production rate and cumulative gas production through the gas desorption and the permeability increase. The gas content in the coal seam dramatically decreases in the vicinity of the production and heat injection wells under the condition of heat injection, which greatly accelerates the gas drainage. The coal deformation caused by thermal-induced gas desorption has a more dominant effect on the porosity than other factors, i.e., pore pressure, thermal strain and compressive strain.http://www.mdpi.com/1996-1073/11/7/1722thermo-hydro-mechanical modeltemperaturepermeabilityporosityheat injection |
| spellingShingle | Yi Xue Faning Dang Zhengzheng Cao Feng Du Fei Liu Jie Ren Feng Gao Numerical Analysis of Heat and Gas Transfer Characteristics during Heat Injection Processes Based on a Thermo-Hydro-Mechanical Model Energies thermo-hydro-mechanical model temperature permeability porosity heat injection |
| title | Numerical Analysis of Heat and Gas Transfer Characteristics during Heat Injection Processes Based on a Thermo-Hydro-Mechanical Model |
| title_full | Numerical Analysis of Heat and Gas Transfer Characteristics during Heat Injection Processes Based on a Thermo-Hydro-Mechanical Model |
| title_fullStr | Numerical Analysis of Heat and Gas Transfer Characteristics during Heat Injection Processes Based on a Thermo-Hydro-Mechanical Model |
| title_full_unstemmed | Numerical Analysis of Heat and Gas Transfer Characteristics during Heat Injection Processes Based on a Thermo-Hydro-Mechanical Model |
| title_short | Numerical Analysis of Heat and Gas Transfer Characteristics during Heat Injection Processes Based on a Thermo-Hydro-Mechanical Model |
| title_sort | numerical analysis of heat and gas transfer characteristics during heat injection processes based on a thermo hydro mechanical model |
| topic | thermo-hydro-mechanical model temperature permeability porosity heat injection |
| url | http://www.mdpi.com/1996-1073/11/7/1722 |
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