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Surface Diffusion in Nanopores and Its Effects on Total Mass Transport in Shale Gas Reservoirs

In the 21st century, shale gas reservoirs have emerged as a significant and valuable source of natural gas. However, their distinct characteristics, particularly the nanoscale pore throat and pore-size distribution, set them apart from conventional reservoirs. These unique features have a profound impact on the storage and flow behavior of hydrocarbons within the shale, making them challenging to exploit using conventional methods. One of the primary challenges associated with shale gas reservoirs is the confined space phase behavior, which alters the fluid properties compared to what is typically observed in a standard PVT (Pressure-Volume-Temperature) cell. In particular, the increased surface adsorption of gas molecules in the shale leads to deviations in fluid properties. This means that the properties of gas within the shale differ from those predicted by conventional models, making it crucial to understand and account for these differences to efficiently extract gas from these reservoirs. Surface diffusion is a critical parameter in assessing the transport ability of adsorbed gas in shale organic matter. Surface diffusion refers to the movement of gas molecules along the surfaces of organic matter in the shale. It is a complex process influenced by various factors. Recent research has provided some insights, indicating that the shale-methane surface diffusion coefficient has a value of around 10-16 cm2/g. However, accurately measuring this coefficient remains a challenge, and there is a need for a definitive and reliable method to do so. Despite the importance of surface diffusion, it has been found that its contribution to total mass transport in shale gas reservoirs is not as significant as previously anticipated. Other mechanisms, such as desorption and matrix diffusion, also play essential roles in the overall transport of gas within shale. To improve our understanding of shale gas reservoirs and optimize gas extraction, this paper proposes an interdisciplinary approach. It suggests combining insights and advances from different industries and fields of research to gain a comprehensive understanding of these complex reservoirs. By bringing together knowledge from geology, engineering, chemistry, and other relevant disciplines, researchers can develop more accurate models and strategies to unlock the full potential of shale gas reservoirs. In summary, shale gas reservoirs have revolutionized the natural gas industry in the 21st century, but their unique characteristics require a specialized approach. Surface diffusion is an important factor affecting gas transport in shale, but its contribution is not as significant as initially thought. Through interdisciplinary research, we can enhance our understanding of these reservoirs and develop more efficient methods for gas extraction.

Surface Diffusion, Nanopores, Shale Gas Reservoirs, Adsorption, Diffusion Coefficient

Ekrem Alagoz, Muhammed Said Ergul. (2023). Surface Diffusion in Nanopores and Its Effects on Total Mass Transport in Shale Gas Reservoirs. International Journal of Energy and Environmental Science, 8(4), 73-78.

Copyright © 2023 Authors retain the copyright of this article.
This article is an open access article distributed under the Creative Commons Attribution License ( which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

1. Seebauer, E. G., & Allen, C. E. (1995). Estimating surface diffusion coefficients. Progress in surface science, 49 (3), 265-330.
2. Yuhui Li, Ajay Annamareddy, Dane Morgan, Zheng Yu, Bu Wang, Chengrong Cao, John H. Perepezko, M. D. Ediger, Paul M. Voyles, and Lian Yu. Surface Diffusion Is Controlled by Bulk Fragility across All Glass Types. Phys. Rev. Lett. 128, 075501.
3. Wang, W., Wang, M., Ambrosi, E. et al. Surface diffusion-limited lifetime of silver and copper nanofilaments in resistive switching devices. Nat Commun 10, 81 (2019).
4. Wang, X., Zheng, S., Shinzato, S. et al. Atomistic processes of surface-diffusion-induced abnormal softening in nanoscale metallic crystals. Nat Commun 12, 5237 (2021).
5. Liu, Zizhong, and Hamid Emami-Meybodi. "Continuum-Scale Gas Transport Modeling in Organic Nanoporous Media Based on Pore-Scale Density Distributions." Paper presented at the SPE Annual Technical Conference and Exhibition, Dubai, UAE, September 2021. doi:
6. He, Lang, Yang, Bin, Liu, Jing, Na, Xinyue, and Yang Ge. "A Novel Apparent Permeability Model in Shale Gas Reservoirs." Paper presented at the Offshore Technology Conference Asia, Virtual and Kuala Lumpur, Malaysia, March 2022. doi:
7. Qian, Cheng, Rui, Zhenhua, Liu, Yueliang, Zhao, Yang, Li, Huazhou Andy, Ma, An, Afanasyev, Andrey, and Farshid Torabi. "Influence of Hydrogen Sulfide on Adsorption Behavior of CO2/CH4 Mixtures in Calcite Nanopores with the Implications for CO2 Sequestration." Paper presented at the Offshore Technology Conference, Houston, Texas, USA, May 2023. doi:
8. Xiong, Hao, and Deepak Devegowda. "Fluid Behavior in Clay-Hosted Nanopores with Varying Salinity: Insights into Molecular Dynamics." SPE J. 27 (2022): 1396–1410. doi:
9. Feng, Dong, Chen, Zhangxin, Zhang, Zenghua, Li, Peihuan, Chen, Yu, Wu, Keliu, and Jing Li. "Effect of Surface Wettability on the Miscible Behaviors Of Co2-Hydrocarbon in Shale Nanopores." Paper presented at the SPE EuropEC - Europe Energy Conference featured at the 83rd EAGE Annual Conference & Exhibition, Madrid, Spain, June 2022. doi:
10. Bienfait, M., Asmussen, B., Johnson, M., Zeppenfeld, P. 2000. Methane mobility in carbon nanotubes. Surface Science, 460, Issues 1–3, 243-248.
11. Binder, T., Chmelik, C., Kärger, J., Martinez-Joaristi, A., Gascon, J., Kapteijn, F., & Ruthven, D. 2013. A diffusion study of small hydrocarbons in DDR zeolites by micro-imaging. Microporous and mesoporous materials, 180, 219-228.
12. Etminan, S. R., Javadpour, F., Maini, B. B., Chen, Z. 2014. Measurement of gas storage processes in shale and of the molecular diffusion coefficient in kerogen. International Journal of Coal Geology, 123, 10-19.
13. Krooss, B. M., Leythaeuser, D. 1988. Experimental measurements of the diffusion parameters of light hydrocarbons in water-saturated sedimentary rocks-II results and geochemical significance. Organic Geochemistry, 12 (2), 91-108.
14. Ning, Y., He, S., Liu, H., Wang, H., & Qin, G. 2016 Permeability prediction considering surface diffusion for gas shales by Lattice Boltzmann Simulations on multi-scale reconstructed digital rocks. International Petroleum Technology Conference.
15. Prasetyo, I., Do, D. D. 1988. Adsorption rate of methane and carbon dioxide on activated carbon by the semi-batch constant molar flow rate method. Chemical Engineering Science, 53, Issue 19 3459-3467.
16. Travalloni, L., Castier, M., Tavares, F. W., Sandler, S. I. 2010. Critical behavior of pure confined fluids from an extension of the van der Waals equation of state. The Journal of Supercritical Fluids, 55 (2), 455-461.