Methane Diffusion and Adsorption in Shale Rocks: A Numerical Study Using the Dusty Gas Model in TOUGH2/EOS7C-ECBM
| العنوان: | Methane Diffusion and Adsorption in Shale Rocks: A Numerical Study Using the Dusty Gas Model in TOUGH2/EOS7C-ECBM |
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| المؤلفون: | Shen, W, Zheng, L, Oldenburg, CM, Cihan, A, Wan, J, Tokunaga, TK |
| المصدر: | Transport in Porous Media, vol 123, iss 3 Shen, W; Zheng, L; Oldenburg, CM; Cihan, A; Wan, J; & Tokunaga, TK. (2018). Methane Diffusion and Adsorption in Shale Rocks: A Numerical Study Using the Dusty Gas Model in TOUGH2/EOS7C-ECBM. Transport in Porous Media, 123(3), 521-531. doi: 10.1007/s11242-017-0985-y. Lawrence Berkeley National Laboratory: Retrieved from: http://www.escholarship.org/uc/item/1gq434q2 |
| بيانات النشر: | eScholarship, University of California, 2018. |
| سنة النشر: | 2018 |
| مصطلحات موضوعية: | Environmental Engineering, Applied Mathematics, Shale gas reservoirs, Adsorption, Chemical Engineering, Methane diffusion, Dusty gas model, Civil Engineering, TOUGH2 |
| الوصف: | © 2017, Springer Science+Business Media B.V., part of Springer Nature. Gas production from shale gas reservoirs plays a significant role in satisfying increasing energy demands. Compared with conventional sandstone and carbonate reservoirs, shale gas reservoirs are characterized by extremely low porosity, ultra-low permeability and high clay content. Slip flow, diffusion, adsorption and desorption are the primary gas transport processes in shale matrix, while Darcy flow is restricted to fractures. Understanding methane diffusion and adsorption, and gas flow and equilibrium in the low-permeability matrix of shale is crucial for shale formation evaluation and for predicting gas production. Modeling of diffusion in low-permeability shale rocks requires use of the Dusty gas model (DGM) rather than Fick’s law. The DGM is incorporated in the TOUGH2 module EOS7C-ECBM, a modified version of EOS7C that simulates multicomponent gas mixture transport in porous media. Also included in EOS7C-ECBM is the extended Langmuir model for adsorption and desorption of gases. In this study, a column shale model was constructed to simulate methane diffusion and adsorption through shale rocks. The process of binary CH4- N2diffusion and adsorption was analyzed. A sensitivity study was performed to investigate the effects of pressure, temperature and permeability on diffusion and adsorption in shale rocks. The results show that methane gas diffusion and adsorption in shale is a slow process of dynamic equilibrium, which can be illustrated by the slope of a curve in CH4mass variation. The amount of adsorption increases with the pressure increase at the low pressure, and the mass change by gas diffusion will decrease due to the decrease in the compressibility factor of the gas. With the elevated temperature, the gas molecules move faster and then the greater gas diffusion rates make the process duration shorter. The gas diffusion rate decreases with the permeability decrease, and there is a limit of gas diffusion if the permeability is less than 1.0×10-15m2. The results can provide insights for a better understanding of methane diffusion and adsorption in the shale rocks so as to optimize gas production performance of shale gas reservoirs. |
| وصف الملف: | application/pdf |
| DOI: | 10.1007/s11242-017-0985-y. |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=dedup_wf_001::13ceac84c2b9b8f7e57056fc9aad9582 https://escholarship.org/uc/item/1gq434q2 |
| Rights: | OPEN |
| رقم الانضمام: | edsair.dedup.wf.001..13ceac84c2b9b8f7e57056fc9aad9582 |
| قاعدة البيانات: | OpenAIRE |
| DOI: | 10.1007/s11242-017-0985-y. |
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