Field Investigation of Hydraulic Fracturing in Coal Seams and Its Enhancement for Methane Extraction in the Southeast Sichuan Basin, China
Hydraulic fracturing is an effective technology for enhancing the extraction of reservoir methane, as proved by field experience and laboratory experiments. However, unlike conventional reservoirs, coal seams had high stress sensitivity and high anisotropy. Therefore, the efficiency of hydraulic fra...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2018-12-01
|
| Series: | Energies |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1996-1073/11/12/3451 |
| _version_ | 1828114730524344320 |
|---|---|
| author | Zuxun Zhang Hongtu Wang Bozhi Deng Minghui Li Dongming Zhang |
| author_facet | Zuxun Zhang Hongtu Wang Bozhi Deng Minghui Li Dongming Zhang |
| author_sort | Zuxun Zhang |
| collection | DOAJ |
| description | Hydraulic fracturing is an effective technology for enhancing the extraction of reservoir methane, as proved by field experience and laboratory experiments. However, unlike conventional reservoirs, coal seams had high stress sensitivity and high anisotropy. Therefore, the efficiency of hydraulic fracturing in coal seams needs to be investigated. In this study, hydraulic fracturing was performed at Nantong mine in the southeast Sichuan basin, China. The field investigation indicated that the hydraulic fracturing could significantly enhance the methane extraction rate of boreholes ten times higher than that of normal boreholes in one of the minable coal seams (named #5 coal seam). The performance of hydraulic fracturing in three districts revealed that compared with south flank, the fluid pressure was higher and the injection rate was lower in north flank. The methane extraction rate of south flank was inferior to that of north flank. It indicated hydraulic fracturing had less effect on #5 coal seam in south flank. Moreover, the injection of high-pressure water in coal seams could also drive methane away from boreholes. The methane extraction rate of the test boreholes demonstrated the existence of methane enrichment circles after hydraulic fracturing. It indicated that hydraulic fracturing did act on #5 coal seam in south flank. However, due to the high stress sensitivity of coal seams and the high geo-stress of south flank, the induced artificial fractures in #5 coal seam might close with the decline of the fluid pressure that led to a sharp decline of the methane extraction rate. |
| first_indexed | 2024-04-11T12:30:21Z |
| format | Article |
| id | doaj.art-9451b614cc5348e285dfa24e0c3e5772 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-04-11T12:30:21Z |
| publishDate | 2018-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-9451b614cc5348e285dfa24e0c3e57722022-12-22T04:23:47ZengMDPI AGEnergies1996-10732018-12-011112345110.3390/en11123451en11123451Field Investigation of Hydraulic Fracturing in Coal Seams and Its Enhancement for Methane Extraction in the Southeast Sichuan Basin, ChinaZuxun Zhang0Hongtu Wang1Bozhi Deng2Minghui Li3Dongming Zhang4State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400030, ChinaState Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400030, ChinaState Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400030, ChinaState Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400030, ChinaState Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400030, ChinaHydraulic fracturing is an effective technology for enhancing the extraction of reservoir methane, as proved by field experience and laboratory experiments. However, unlike conventional reservoirs, coal seams had high stress sensitivity and high anisotropy. Therefore, the efficiency of hydraulic fracturing in coal seams needs to be investigated. In this study, hydraulic fracturing was performed at Nantong mine in the southeast Sichuan basin, China. The field investigation indicated that the hydraulic fracturing could significantly enhance the methane extraction rate of boreholes ten times higher than that of normal boreholes in one of the minable coal seams (named #5 coal seam). The performance of hydraulic fracturing in three districts revealed that compared with south flank, the fluid pressure was higher and the injection rate was lower in north flank. The methane extraction rate of south flank was inferior to that of north flank. It indicated hydraulic fracturing had less effect on #5 coal seam in south flank. Moreover, the injection of high-pressure water in coal seams could also drive methane away from boreholes. The methane extraction rate of the test boreholes demonstrated the existence of methane enrichment circles after hydraulic fracturing. It indicated that hydraulic fracturing did act on #5 coal seam in south flank. However, due to the high stress sensitivity of coal seams and the high geo-stress of south flank, the induced artificial fractures in #5 coal seam might close with the decline of the fluid pressure that led to a sharp decline of the methane extraction rate.https://www.mdpi.com/1996-1073/11/12/3451hydraulic fracturingcoal seam methanefield investigationmethane extractionmethane enrichment circle |
| spellingShingle | Zuxun Zhang Hongtu Wang Bozhi Deng Minghui Li Dongming Zhang Field Investigation of Hydraulic Fracturing in Coal Seams and Its Enhancement for Methane Extraction in the Southeast Sichuan Basin, China Energies hydraulic fracturing coal seam methane field investigation methane extraction methane enrichment circle |
| title | Field Investigation of Hydraulic Fracturing in Coal Seams and Its Enhancement for Methane Extraction in the Southeast Sichuan Basin, China |
| title_full | Field Investigation of Hydraulic Fracturing in Coal Seams and Its Enhancement for Methane Extraction in the Southeast Sichuan Basin, China |
| title_fullStr | Field Investigation of Hydraulic Fracturing in Coal Seams and Its Enhancement for Methane Extraction in the Southeast Sichuan Basin, China |
| title_full_unstemmed | Field Investigation of Hydraulic Fracturing in Coal Seams and Its Enhancement for Methane Extraction in the Southeast Sichuan Basin, China |
| title_short | Field Investigation of Hydraulic Fracturing in Coal Seams and Its Enhancement for Methane Extraction in the Southeast Sichuan Basin, China |
| title_sort | field investigation of hydraulic fracturing in coal seams and its enhancement for methane extraction in the southeast sichuan basin china |
| topic | hydraulic fracturing coal seam methane field investigation methane extraction methane enrichment circle |
| url | https://www.mdpi.com/1996-1073/11/12/3451 |
| work_keys_str_mv | AT zuxunzhang fieldinvestigationofhydraulicfracturingincoalseamsanditsenhancementformethaneextractioninthesoutheastsichuanbasinchina AT hongtuwang fieldinvestigationofhydraulicfracturingincoalseamsanditsenhancementformethaneextractioninthesoutheastsichuanbasinchina AT bozhideng fieldinvestigationofhydraulicfracturingincoalseamsanditsenhancementformethaneextractioninthesoutheastsichuanbasinchina AT minghuili fieldinvestigationofhydraulicfracturingincoalseamsanditsenhancementformethaneextractioninthesoutheastsichuanbasinchina AT dongmingzhang fieldinvestigationofhydraulicfracturingincoalseamsanditsenhancementformethaneextractioninthesoutheastsichuanbasinchina |