Characterization of water micro-distribution behavior in shale nanopores: A comparison between experiment and theoretical model
Keywords:
Adsorbed water, free water, adsorption ratio equation, nuclear magnetic resonance, centrifugationAbstract
Due to the existence of fracturing fluid and formation water in shale gas reservoirs, the coexistence of gas and water in nanopores is prevalent. The pore water in the reservoir, on the one hand, affects gas flow behavior and permeability. On the other hand, it blocks pore throats and occupies adsorption sites on the pore surface, consequently reducing the gas adsorption capacity. The occurrence of pore water in shale reservoirs holds significant importance for shale gas resources exploration and development. In this paper, the shale from the Longmaxi Formation, Sichuan Basin was selected as the research target. The content and micro-distribution behavior of pore water were evaluated through centrifugation-nuclear magnetic resonance experiment and theoretical model. The results demonstrated that the content of free water would be underestimated by the experiment, with 2.55%-6.80% lower than that calculated by theoretical model. Moreover, due to the limitations of nuclear magnetic resonance experiment, the adsorbed water in mesopores and macropores might be mistakenly identified as that in smaller pores. As a result, the theoretical model is more applicable for characterizing the micro-distribution behavior of pore water than the origin nuclear magnetic resonance data.
Document Type: Short communication
Cited as: Jiao, X., He, W., Tian, Z., Zhou, S., Wang, H., Xia, Y. Characterization of water micro-distribution behavior in shale nanopores: A comparison between experiment and theoretical model. Advances in Geo-Energy Research, 2025, 15(1): 79-86. https://doi.org/10.46690/ager.2025.01.08
ReferencesBai, J., Kang, Y., Chen, M., et al. Impact of surface chemistry and pore structure on water vapor adsorption behavior in gas shale. Chemical Engineering Journal, 2020, 402: 126238.
Barrett, E. P., Joyner, L. G., Halenda, P. P. The determination of pore volume and area distributions in porous substances. I. Computations from nitrogen isotherms. Journal of the American Chemical Society, 1951, 73(1): 373-380.
Boampong, L. O., Rafati, R., Sharifi Haddad, A. A calibrated surface complexation model for carbonate-oil-brine interactions coupled with reservoir simulation—Application to controlled salinity water flooding. Journal of Petroleum Science and Engineering, 2022, 208: 109314.
Brunauer, S., Emmett, P. H., Teller, E. Adsorption of gases in multimolecular layers. Journal of the American Chemical Society, 1938, 60(2): 309-319.
Cai, J., Jiao, X., Wang, H., et al. Multiphase fluid-rock interactions and flow behaviors in shale nanopores: A comprehensive review. Earth-Science Reviews, 2024, 257: 104884.
Duan, S., Geng, L., Li, G., et al. Water vapour adsorption isotherms of shales: Thermodynamic properties and microstructure. Fluid Phase Equilibria, 2023, 563: 113583.
Estrada, J. M., Bhamidimarri, R. A review of the issues and treatment options for wastewater from shale gas extraction by hydraulic fracturing. Fuel, 2016, 182: 292-303.
Fan, Q., Cheng, P., Tian, H., et al. Distribution and occurrence of pore water and retained oil in nanopores of marine-terrestrial transitional shales during oil generation and expulsion: Implications from a thermal simulation experiment on shale plug samples. Marine and Petroleum Geology, 2023, 150: 106125.
Fleury, M., Romero-Sarmiento, M. Characterization of shales using T1-T2 NMR maps. Journal of Petroleum Science and Engineering, 2016, 137: 55-62.
Gao, Z., Xiong, S., Wei, L. The new multistage water adsorp tion model of Longmaxi Formation shale considering the spatial configuration relationship between organic matter and clay minerals. Petroleum Science, 2022, 19(5): 1950-1963.
Han, Y., Jiang, Z., Liang, Z., et al. Study on the multifractal characterization and seepage of the shale matrix: A case study of the Longmaxi Formation in southwestern Sichuan Basin, China. Geoenergy Science and Engineering, 2024, 238: 212924.
Jia, T., Zhang, S., Tang, S., et al. Water-bearing properties of high rank coal reservoir and the effect on multiphase methane. Gas Science and Engineering, 2024, 128: 205380.
Liang, L., Luo, D., Liu, X., et al. Experimental study on the wettability and adsorption characteristics of Longmaxi Formation shale in the Sichuan Basin, China. Journal of Natural Gas Science and Engineering, 2016, 33: 1107-1118.
Li, J., Cai, J. Quantitative characterization of fluid occurrence in shale reservoirs. Advances in Geo-Energy Research, 2023, 9(3): 146-151.
Li, J., Wang, Y., Song, Z., et al. Mobility of connate pore water in gas shales: A quantitative evaluation on the Longmaxi shales in the southern Sichuan Basin, China. Marine and Petroleum Geology, 2024, 161: 106674.
Li, J., Zhou, Z., Wang, M., et al. Storage capacity and microdistribution of pore water in gas-producing shales: A collaborative evaluation by centrifugation and nuclear magnetic resonance. Energy & Fuels, 2023, 37(17): 12980-12993.
Li, S., Lei, Q., Wang, X., et al. Permeability regain and aqueous phase migration during hydraulic fracturing shut-ins. Scientific Reports, 2019, 9(1): 1818.
Liu, Y., Yao, Y., Liu, D., et al. Shale pore size classification: An NMR fluid typing method. Marine and Petroleum Geology, 2018, 96: 591-601.
Lyu, F., Ning, Z., Jia, Z., et al. Investigation on gas/water two-phase flow in quartz nanopores from molecular perspectives. Journal of Molecular Liquids, 2023, 371: 121145.
Medeiros, D. C. C. S., Chelme-Ayala, P., Benally, C., et al. Review on carbon-based adsorbents from organic feedstocks for removal of organic contaminants from oil and gas industry process water: Production, adsorption performance and research gaps. Journal of Environmental Management, 2022, 320: 115739.
Meng, M., Ge, H., Shen, Y., et al. Insight into water occurrence and pore size distribution by nuclear magnetic resonance in marine shale reservoirs, southern China. Energy & Fuels, 2023, 37(1): 319-327.
Mu, Y., Hu, Z., Shen, R., et al. Water occurrence characteris tics of gas shale based on 2D NMR technology. Energy & Fuels, 2022, 36(2): 910-921.
Qin, X., Wu, J., Xia, Y., et al. Multicomponent image-based modeling of water flow in heterogeneous wet shale nanopores. Energy, 2024, 298: 131367.
Saidian, M., Prasad, M. Effect of mineralogy on nuclear magnetic resonance surface relaxivity: A case study of Middle Bakken and Three Forks Formations. Fuel, 2015, 161: 197-206.
Testamanti, M. N., Rezaee, R. Determination of NMR T2 cut-off for clay bound water in shales: A case study of Carynginia Formation, Perth Basin, Western Australia. Journal of Petroleum Science and Engineering, 2017, 149: 497-503.
Wei, J., Yang, E., Li, J., et al. Nuclear magnetic resonance study on the evolution of oil water distribution in multistage pore networks of shale oil reservoirs. Energy, 2023, 282: 128714.
Wu, M., Chang, X., Guo, Y., et al. Advances, challenges, and opportunities for hydraulic fracturing of deep shale gas reservoirs. Advances in Geo-Energy Research, 2025, 15(1): 1-4.
Xia, X., Xia, Y., Zhao, F., et al. Evaluating the surface relaxivity and movable fluid of low-permeability sandstones based on low-field nuclear magnetic resonance. Physics of Fluids, 2024, 36(11): 116619.
Xie, W., Wang, H., Chen, S., et al. Water adsorption and its pore structure dependence in shale gas reservoirs. Langmuir, 2023, 39(30): 10576-10592.
Xu, H., Yu, H., Fan, J., et al. Two-phase transport characteristic of shale gas and water through hydrophilic and hydrophobic nanopores. Energy & Fuels, 2020, 34(4): 4407-4420.
Xu, J., Zhan, S., Wang, W., et al. Molecular dynamics simulations of two-phase flow of n-alkanes with water in quartz nanopores. Chemical Engineering Journal, 2022, 430: 132800.
Yang, R., Jia, A., He, S., et al. Water adsorption characteristics of organic-rich Wufeng and Longmaxi Shales, Sichuan Basin (China). Journal of Petroleum Science and Engi neering, 2020, 193: 107387.
Yang, Y., Song, H., Imani, G., et al. Adsorption behavior of shale oil and water in the kerogen-kaolinite pore by molecular simulations. Journal of Molecular Liquids, 2024, 393: 123549.
Yu, H., Xu, H., Fan, J., et al. Transport of shale gas in microporous/nanoporous media: Molecular to pore-scale simulations. Energy & Fuels, 2021, 35(2): 911-943.
Yuan, Y., Rezaee, R., Zhou, M.-F., et al. A comprehen sive review on shale studies with emphasis on nuclear magnetic resonance (NMR) technique. Gas Science and Engineering, 2023, 120: 205163.
Zhang, C., Yao, Y., Swennen, R., et al. Combined effects of the chemical structure and nanopore development on water vapor/liquid adsorption in shale kerogen. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2022, 653: 129920.
Zhang, D., Tang, H., Song, Y., et al. Molecular simulation of the competitive adsorption of methane and carbon dioxide in the matrix and slit model of shale kerogen and the influence of water. Geoenergy Science and Engineering, 2024a, 242: 213212.
Zhang, L., Yan, W., Fu, J., et al. Methane gas transport in Ca-MMT shale nanoslits considering water content effects: Insights from molecular dynamics simulations. Langmuir, 2024b, 40(47): 25110-25117.
Zhang, S., Wang, T., Gao, Z., et al. Wettability controlling effects on the fluid occurrence and flow in shale gas reservoirs: Present problems and new sights. Capillarity, 2023, 9(2): 25-31.
Zhao, T., Xu, S., Hao, F. Differential adsorption of clay minerals: Implications for organic matter enrichment. Earth-Science Reviews, 2023, 246: 104598.
Zheng, S., Yao, Y., Liu, D., et al. Re-evaluating the accurate multiphase water distribution in coals: Unifying exper iment and theory. Chemical Engineering Journal, 2023, 464: 142637.
Zhou, Z., Li, J., Song, Z., et al. Occurrence characteristics of water in nano-slit pores under different solution con ditions: A case study on kaolinite. ACS Omega, 2023, 8(21): 18990-19001.