Characteristics of Pore Structure in Coal from the Chengzhuang Mining Area

Yilong Chen

doi:10.62051/

Authors

Yilong Chen

DOI:

https://doi.org/10.62051/

Keywords:

Pore Structure; High-Pressure Mercury Intrusion; Low-Temperature Nitrogen Adsorption.

Abstract

To investigate the pore structure characteristics and multi-scale distribution of coal in the Chengzhuang mining area, coal samples from the Shanxi Formation were selected for analysis. High-pressure mercury intrusion (MIP), low-temperature nitrogen adsorption (LTNA), and scanning electron microscopy (SEM) were employed to comprehensively characterize pore types, pore size distribution, and pore-throat structure. The results indicate that the pore system in the study area is mainly composed of metamorphic pores and exogenous pores, with relatively poor connectivity. The MIP results show that the pore volume of both samples is dominated by transitional pores, followed by micropores, while mesopores and macropores account for relatively small proportions, suggesting that the pore system is primarily composed of small- to medium-scale pores. The LTNA results reveal that transitional pores contribute significantly to the pore volume, whereas micropores dominate the specific surface area. This indicates that pore volume is mainly controlled by transitional pores, while the specific surface area is primarily governed by micropores.

References

[1] Guo H, Yu Y, Guo D, et al. Research on physical properties of tectonic coal reservoir and its influence on coalbed methane development: a review[J]. Fuel, 2026, 407.

[2] Ranathunga A S, Perera M S A, Ranjith P G. Deep coal seams as a greener energy source: a review[J]. Journal of Geophysics and Engineering, 2014, 11(6).

[3] Karacan C O, Ruiz F A, Cote M, et al. Coal mine methane: a review of capture and utilization practices with benefits to mining safety and to greenhouse gas reduction[J]. International Journal of Coal Geology, 2011, 86(2-3): 121-156.

[4] Andrews-Speed P, Xu X, Jie D, et al. Deficiencies in China’s innovation systems for coal-bed methane development: comparison with the USA[J]. Journal of Science and Technology Policy Management, 2022, ahead-of-print.

[5] Xian B, Liu G, Bi Y, et al. Coalbed methane recovery enhanced by screen pipe completion and jet flow washing of horizontal well double tubular strings[J]. Journal of Natural Gas Science and Engineering, 2022, 99.

[6] Coalbed methane: reserves, production, and future outlook[J]. Future energy, 2020: 97-109.

[7] Li Y, Liu W, Song D, et al. Full-scale pore characteristics in coal and their influence on the adsorption capacity of coalbed methane[J]. Environmental Science and Pollution Research, 2023, 30(28): 72187-72206.

[8] Lu F, Liu C, Zhang X, et al. Study on full-scale pores characterization and heterogeneity of coal based on low-temperature nitrogen adsorption and low-field nuclear magnetic resonance experiments[J]. Scientific Reports, 2024, 14(1): 16910.

[9] Tao S, Pan Z, Chen S, et al. Coal seam porosity and fracture heterogeneity of marcolithotypes in the fanzhuang block, southern qinshui basin, china[J]. Journal of Natural Gas Science and Engineering, 2019, 66: 148-158.

[10] Wang K, Guo L, Xu C, et al. Multiscale characteristics of pore-fracture structures in coal reservoirs and their influence on coalbed methane (CBM) transport: a review[J]. Geoenergy Science and Engineering, 2024, 242: 213181.

[11] Yao Y, Liu D, Che Y, et al. Petrophysical characterization of coals by low-field nuclear magnetic resonance (NMR)[J]. Fuel, 2010, 89(7): 1371-1380.

[12] Guo C, Qin Y, Ma D, et al. Pore structure response of sedimentary cycle in coal-bearing strata and implications for independent superposed coalbed methane systems[J]. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020: 1-20.