An experimental investigation of the nonlinear gas flow and stress‐dependent permeability of shale fractures
Abstract The fluid flow characteristics in shale fractures are of great significance for shale gas reservoir evaluation and exploitation. In this study, artificial tension fractures in shale were used to simulate the hydraulic fractures formed by fracturing, and a gas flow test under different press...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Wiley
2020-08-01
|
| Series: | Energy Science & Engineering |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/ese3.696 |
| _version_ | 1818325715914850304 |
|---|---|
| author | Zhonghui Shen Lei Zhou Xiaopeng Su Honglian Li Jiren Tang Xuelin Zheng |
| author_facet | Zhonghui Shen Lei Zhou Xiaopeng Su Honglian Li Jiren Tang Xuelin Zheng |
| author_sort | Zhonghui Shen |
| collection | DOAJ |
| description | Abstract The fluid flow characteristics in shale fractures are of great significance for shale gas reservoir evaluation and exploitation. In this study, artificial tension fractures in shale were used to simulate the hydraulic fractures formed by fracturing, and a gas flow test under different pressure gradients was conducted. The nonlinear gas flow and stress‐dependent permeability characteristics were analyzed. The experimental results show the following: (a) CO2 flow in shale fractures exhibits strong nonlinearity. Forchheimer's law, which considers gas compressibility, satisfactorily describes the nonlinear relationship between the flow rate and the pressure gradients in shale fractures. (b) The permeability sensitivity of shale fractures under stress is very strong, and the exponential relationship better describes the pressure dependency of the permeability for the tested shale samples. The permeability of the shale fractures is similar when measured parallel or perpendicular to bedding. Furthermore, the pressure dependence of fractures in shale obeys the Walsh permeability model. (c) As the effective stress increases, the nonlinear flow behavior appears earlier. Based on the Reynolds number and the nonlinear coefficient, a friction factor model is proposed. (d) The normalized transmissivity exhibits a strong correlation with the Reynolds number. CO2 flow through shale fractures is generally dominated by transitional flow. The critical Reynolds number ranges from 1.8 to 102.88 and decreases with increasing effective stress. |
| first_indexed | 2024-12-13T11:48:54Z |
| format | Article |
| id | doaj.art-d67449fd3ba748128829c241f0643aa6 |
| institution | Directory Open Access Journal |
| issn | 2050-0505 |
| language | English |
| last_indexed | 2024-12-13T11:48:54Z |
| publishDate | 2020-08-01 |
| publisher | Wiley |
| record_format | Article |
| series | Energy Science & Engineering |
| spelling | doaj.art-d67449fd3ba748128829c241f0643aa62022-12-21T23:47:25ZengWileyEnergy Science & Engineering2050-05052020-08-01882808282210.1002/ese3.696An experimental investigation of the nonlinear gas flow and stress‐dependent permeability of shale fracturesZhonghui Shen0Lei Zhou1Xiaopeng Su2Honglian Li3Jiren Tang4Xuelin Zheng5State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing University Chongqing ChinaState Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing University Chongqing ChinaState Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing University Chongqing ChinaState Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing University Chongqing ChinaState Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing University Chongqing ChinaState Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing University Chongqing ChinaAbstract The fluid flow characteristics in shale fractures are of great significance for shale gas reservoir evaluation and exploitation. In this study, artificial tension fractures in shale were used to simulate the hydraulic fractures formed by fracturing, and a gas flow test under different pressure gradients was conducted. The nonlinear gas flow and stress‐dependent permeability characteristics were analyzed. The experimental results show the following: (a) CO2 flow in shale fractures exhibits strong nonlinearity. Forchheimer's law, which considers gas compressibility, satisfactorily describes the nonlinear relationship between the flow rate and the pressure gradients in shale fractures. (b) The permeability sensitivity of shale fractures under stress is very strong, and the exponential relationship better describes the pressure dependency of the permeability for the tested shale samples. The permeability of the shale fractures is similar when measured parallel or perpendicular to bedding. Furthermore, the pressure dependence of fractures in shale obeys the Walsh permeability model. (c) As the effective stress increases, the nonlinear flow behavior appears earlier. Based on the Reynolds number and the nonlinear coefficient, a friction factor model is proposed. (d) The normalized transmissivity exhibits a strong correlation with the Reynolds number. CO2 flow through shale fractures is generally dominated by transitional flow. The critical Reynolds number ranges from 1.8 to 102.88 and decreases with increasing effective stress.https://doi.org/10.1002/ese3.696critical reynolds numbernonlinear flowshale fracturesstress sensitivitystress‐dependent permeability |
| spellingShingle | Zhonghui Shen Lei Zhou Xiaopeng Su Honglian Li Jiren Tang Xuelin Zheng An experimental investigation of the nonlinear gas flow and stress‐dependent permeability of shale fractures Energy Science & Engineering critical reynolds number nonlinear flow shale fractures stress sensitivity stress‐dependent permeability |
| title | An experimental investigation of the nonlinear gas flow and stress‐dependent permeability of shale fractures |
| title_full | An experimental investigation of the nonlinear gas flow and stress‐dependent permeability of shale fractures |
| title_fullStr | An experimental investigation of the nonlinear gas flow and stress‐dependent permeability of shale fractures |
| title_full_unstemmed | An experimental investigation of the nonlinear gas flow and stress‐dependent permeability of shale fractures |
| title_short | An experimental investigation of the nonlinear gas flow and stress‐dependent permeability of shale fractures |
| title_sort | experimental investigation of the nonlinear gas flow and stress dependent permeability of shale fractures |
| topic | critical reynolds number nonlinear flow shale fractures stress sensitivity stress‐dependent permeability |
| url | https://doi.org/10.1002/ese3.696 |
| work_keys_str_mv | AT zhonghuishen anexperimentalinvestigationofthenonlineargasflowandstressdependentpermeabilityofshalefractures AT leizhou anexperimentalinvestigationofthenonlineargasflowandstressdependentpermeabilityofshalefractures AT xiaopengsu anexperimentalinvestigationofthenonlineargasflowandstressdependentpermeabilityofshalefractures AT honglianli anexperimentalinvestigationofthenonlineargasflowandstressdependentpermeabilityofshalefractures AT jirentang anexperimentalinvestigationofthenonlineargasflowandstressdependentpermeabilityofshalefractures AT xuelinzheng anexperimentalinvestigationofthenonlineargasflowandstressdependentpermeabilityofshalefractures AT zhonghuishen experimentalinvestigationofthenonlineargasflowandstressdependentpermeabilityofshalefractures AT leizhou experimentalinvestigationofthenonlineargasflowandstressdependentpermeabilityofshalefractures AT xiaopengsu experimentalinvestigationofthenonlineargasflowandstressdependentpermeabilityofshalefractures AT honglianli experimentalinvestigationofthenonlineargasflowandstressdependentpermeabilityofshalefractures AT jirentang experimentalinvestigationofthenonlineargasflowandstressdependentpermeabilityofshalefractures AT xuelinzheng experimentalinvestigationofthenonlineargasflowandstressdependentpermeabilityofshalefractures |