1887
Volume 72, Issue 7
  • E-ISSN: 1365-2478

Abstract

Abstract

The heterogeneity in permeability of coal reservoirs is primarily attributed to the considerable variation in the morphologies and structures of microscopic pore‐fractures, shaped by complex geological processes. This study emphasizes the necessity of understanding the impact and governance of these morphological and structural variations in pore‐fractures across different types of coal bodies on their permeability. Utilizing computerized tomography scanning and three‐dimensional imaging, we examined coal samples from the Datong coalfield in the southeastern Qinshui Basin, Shanxi Province, to characterize the pore‐fracture morphologies and structures distinct to various coal‐body types based on tomographic data. This introduces a methodology for assessing the influence of microscopic pore‐fracture parameters, such as porosity, specific surface area, tortuosity and fractal dimension, on permeability sensitivity. This is achieved through the application of the modified Kozeny–Carman equation and a fractal permeability model. Findings indicate a predominance of slab fractures in raw coal, whereas fragmented coal under weak brittle deformation exhibits small, isolated pore‐fractures with minimal diameter and volume and poor connectivity. In contrast, granular coal subjected to strong brittle deformation features extensive clusters of large pore‐fractures with significant diameter and volume, enhancing connectivity. Moreover, permeability predictions are refined by integrating the modified Kozeny–Carman equation with tomographic data, offering a more precise understanding of the permeability across different coal bodies.

© 2024 European Association of Geoscientists & Engineers. © 2024 European Association of Geoscientists & Engineers.
Loading

Article metrics loading...

/content/journals/10.1111/1365-2478.13551
2024-08-23
2025-11-14

  • From This Site

    /content/journals/10.1111/1365-2478.13551
    dcterms_title,dcterms_subject,pub_keyword
    -contentType:Journal -contentType:Contributor -contentType:Concept -contentType:Institution
    10
    5
Loading full text...

Full text loading...

References

  1. Cai, Y., Liu, D., Yao, Y., Li, J. & Qiu, Y. (2011) Geological controls on prediction of coalbed methane of No. 3 coal seam in southern Qinshui Basin, North China. International Journal of Coal Geology, 88, 101–112. https://doi.org/10.1016/j.coal.2011.08.009
     [Google Scholar]
  2. Carman, P.C. (1937) Fluid flow through granular beds. Chemical Engineering Research & Design, 75, S32–S48. https://doi.org/10.1016/S0263‐8762(97)80003‐2
     [Google Scholar]
  3. Cheng, Y. & Pan, Z. (2020) Reservoir properties of Chinese tectonic coal: a review. Fuel, 260, 116350. https://doi.org/10.1016/j.fuel.2019.116350
     [Google Scholar]
  4. Deng, Y., Wang, S., Meng, Y. & Yang, Z. (2017) Study on brittle failure crack propagation in tight sandstone based on CT scanning. Journal of Hydraulic and Architectural Engineering, 15, 39–43. https://doi.org/10.3969/j.issn.1672‐1144.2017.04.007
     [Google Scholar]
  5. Fang, H., Sang, S., Liu, S., Wang, H. & Zang, L. (2018) Digital petrophysical analysis of coal based on micron focus CT technology: a case study of Bofang No. 3 coal in Qinshui Basin. Coal Geology and Exploration, 46, 167–174. https://CNKI:SUN:MDKT.0.2018‐05‐026
     [Google Scholar]
  6. Guo, P. & Cheng, Y. (2013) Permeability prediction in deep coal seam: A case study on the No. 3 coal seam of the southern Qinshui Basin in China. Scientific World Journal, 2013, 161457. https://doi.org/10.1155/2013/161457.<./bib>
     [Google Scholar]
  7. Henderson, N., Brêttas, J.C. & Sacco, W.F. (2010) A three‐parameter Kozeny–Carman generalized equation for fractal porous media. Chemical Engineering Science, 65, 4432–4442. https://doi.org/10.1016/j.ces.2010.04.006
     [Google Scholar]
  8. Heriawan, M.N. & Koike, K. (2015) Coal quality related to microfractures identified by CT image analysis. International Journal of Coal Geology, 140, 97–110. https://doi.org/10.1016/j.coal.2015.02.001
     [Google Scholar]
  9. Karacan, C.Ö.Z., Ruiz, F.A., Cotè, M. & Phipps, S. (2011) Coal mine methane: a review of capture and utilization practices with benefits to mining safety and to greenhouse gas reduction. International Journal of Coal Geology, 86, 121–156. https://doi.org/10.1016/j.coal.2011.02.009
     [Google Scholar]
  10. Li, B., Wong, R.C.K. & Heidari, S. (2018) A modified Kozeny‐Carman model for estimating anisotropic permeability of soft mudrocks. Marine and Petroleum Geology, 98, 356–368. https://doi.org/10.1016/j.marpetgeo.2018.08.034
     [Google Scholar]
  11. Li, W., Yao, H., Liu, H., Kang, Z., Song, X. & Feng, Z. (2014) Fine characterization of three dimensional pores of coal with different coal structures based on micro CT. Journal of China Coal Society, 39, 1127–1132. https://doi.org/10.13225/j.cnki.jccs.2013.0920
     [Google Scholar]
  12. Liu, X., Xiong, J., Liang, L. & Yuan, W. (2017) Pore structure characteristics of tight sandstone based on micro CT technology and its influence on fluid flow. Progress in Geophysics, 32, 1019–1028. https://doi.org/10.6038/pg20170310
     [Google Scholar]
  13. Meng, Z., Zhang, J. & Wang, R. (2011) In‐situ stress, pore pressure and stress‐dependent permeability in the southern Qinshui Basin. International Journal of Rock Mechanics & Mining Sciences, 48, 122–131. https://doi.org/10.1016/j.ijrmms.2010.10.003
     [Google Scholar]
  14. Nishiyama, N. & Yokoyama, T. (2017) Permeability of porous media: Role of the critical pore size. Journal of Geophysical Research: Solid Earth, 122, 6955–6971. https://doi.org/10.1002/2016JB013793
     [Google Scholar]
  15. Palmer, I. (2009) Permeability changes in coal: Analytical modeling. International Journal of Coal Geology, 77, 119–126. https://doi.org/10.1016/j.coal.2008.09.006
     [Google Scholar]
  16. Pan, J., Hou, Q., Ju, Y., Bai, H. & Zhao, Y. (2012) Coalbed methane sorption related to coal deformation structures at different temperatures and pressures. Fuel, 102, 760–765. https://doi.org/10.1016/j.fuel.2012.07.023
     [Google Scholar]
  17. Pan, J., Zhu, H., Hou, Q., Wang, H. & Wang, S. (2015) Macromolecular and pore structures of Chinese tectonically deformed coal studied by atomic force microscopy. Fuel, 139, 94–101. https://doi.org/10.1016/j.fuel.2014.08.039
     [Google Scholar]
  18. Pan, Z. & Connell, L.D. (2012) Modelling permeability for coal reservoirs: A review of analytical models and testing data. International Journal of Coal Geology, 92, 1–44. https://doi.org/10.1016/j.coal.2011.12.009
     [Google Scholar]
  19. Scuderi, M.M., Kitajima, H., Carpenter, B.M., Saffer, D.M. & Marone, C. (2015) Evolution of permeability across the transition from brittle failure to cataclastic flow in porous siltstone. Geochemistry, Geophysics, Geosystems, 16, 2980–2993. https://doi.org/10.1002/2015GC005932
     [Google Scholar]
  20. Shi, X., Pan, J., Pang, L., Wang, R., Li, G., Tian, J. et al. (2020) 3D microfracture network and seepage characteristics of low‐volatility bituminous coal based on nano‐CT. Journal of Natural Gas Science and Engineering, 83, 103556. https://doi.org/10.1016/j.jngse.2020.103556
     [Google Scholar]
  21. Song, X., Tang, Y., Li, W., Feng, Z., Kang, Z., Li, Y. et al. (2013) Fine characterization of tectonic coal seepage pores based on micrographs. Journal of China Coal Society, 38, 435–440. https://doi.org/10.13225/j.cnki.jccs.2013.03.016
     [Google Scholar]
  22. Sun, J. & Yan, G. (2012) Research progress on permeability models. Logging Technology, 36, 7. https://doi.org/10.16489/j.issn.1004‐1338.2012.04.001
     [Google Scholar]
  23. Wang, C., Hao, S., Sun, W. & Chu, W. (2012) Fractal dimension of coal particles and their CH4 adsorption. Journal of Mining Science and Technology, 22, 855–858. https://doi.org/10.1016/j.ijmst.2012.11.003
     [Google Scholar]
  24. Wang, G., Jiang, C., Liu, S., Chu, X. & Shen, J. (2018) Dynamic simulation of seepage process based on CT 3D reconstruction of coal skeleton structure model. Journal of China Coal Society, 43, 1390–1399. https://doi.org/10.13225/j.cnki.jccs.2017.1199
     [Google Scholar]
  25. Wang, X., Pan, J., Wang, K., Ge, T., Wei, J. & Wu, W. (2020) Characterizing the shape, size, and distribution heterogeneity of pore‐fractures in high rank coal based on X‐ray CT image analysis and mercury intrusion porosimetry. Fuel, 282, 118754. https://doi.org/10.1016/j.fuel.2020.118754
     [Google Scholar]
  26. Wang, X., Pan, J., Wang, K., Li, J., Cheng, N. & Li, M. (2023) Microfissure structure characteristics and its control on permeability of structural coal at micrometer CT scanning scale. Journal of China Coal Society, 48, 1325–1334. https://doi.org/10.13225/j.cnki.jccs.2021.1993
     [Google Scholar]
  27. Xu, P. & Yu, B. (2008) Developing a new form of permeability and Kozeny–Carman constant for homogeneous porous media by means of fractal geometry. Advances in Water Resources, 31, 74–81. https://doi.org/10.1016/j.advwatres.2007.06.003
     [Google Scholar]
  28. Ye, Z., Hou, E., Duan, Z. & Li, Z. (2019) Coal reservoir characterization in a tectonic setting and the effects of tectonism on the coalbed methane (CBM) content. Advances in Materials Science and Engineering, 2019, 1–11. https://doi.org/10.1155/2019/7974628
     [Google Scholar]
  29. Yu, B. & Cheng, P. (2002) A fractal permeability model for bi‐dispersed porous media. International Journal of Heat and Mass Transfer, 45, 2983–2993. https://doi.org/10.1016/S0017‐9310(02)00014‐5
     [Google Scholar]
  30. Yu, B. & Li, J. (2001) Some fractal characters of porous media. Fractals, 09, 365–372. https://doi.org/10.1142/S0218348×01000804
     [Google Scholar]
  31. Yu, B. & Li, J. (2004) A geometry model for tortuosity of flow path in porous media. Chinese Physics Letters, 21, 1569–1571. https://doi.org/10.1088/0256‐307X/21/8/044
     [Google Scholar]
  32. Zhai, J., Wang, J., Lu, G., Qin, X. & Wang, W. (2018) Permeability characteristics of remolded tectonically deformed coal and its influence factors. Journal of Natural Gas Science and Engineering, 53, 22–31. https://doi.org/10.1016/j.jngse.2018.02.023
     [Google Scholar]
  33. Zhang, C., Li, T. & Xiong, Q. (2023) Relationship between litho structure and fracture distribution in coal. Coal Geology & Exploitation, 28, 26–30. https://doi.org/10.3969/j.issn.1001‐1986.2000.05.009
     [Google Scholar]
  34. Zhao, Z., Zhou, X.P. & Qian, Q.H. (2020) Fracture characterization and permeability prediction by pore scale variables extracted from X‐ray CT images of porous geomaterials. Science China Technological Sciences, 63, 755–767. https://doi.org/10.1007/s11431‐019‐1449‐4
     [Google Scholar]
  35. Zheng, B. & Li, J. (2015) Permeability fractal model based on Kozeny‐Carman equation. Natural Gas Geoscience, 26, 193–198. https://doi.org/10.11764/j.issn.1672‐1926.2015.01.0193
     [Google Scholar]
  36. Zou, G., She, J., Peng, S., Yin, Q., Liu, H. & Che, Y. (2020) Two‐dimensional SEM image‐based analysis of coal porosity and its pore structure. International Journal of Coal Science & Technology, 7, 350–361. https://doi.org/10.1007/s40789‐020‐00301‐8
     [Google Scholar]
  37. Zou, G., Zhang, Q., Peng, S., She, J., Teng, D., Jin, C. et al. (2022) Influence of geological factors on coal permeability in the Sihe coal mine. International Journal of Coal Science & Technology, 9, 6. https://doi.org/10.1007/s40789‐022‐00475‐3
     [Google Scholar]
  38. Zou, Q., Lin, B., Zheng, C., Hao, Z., Zhai, C., Liu, T. et al. (2015) Novel integrated techniques of drilling–slotting–separation‐sealing for enhanced coal bed methane recovery in underground coal mines. Journal of Natural Gas Science and Engineering, 26, 960–973. https://doi.org/10.1016/j.jngse.2015.07.033
     [Google Scholar]
/content/journals/10.1111/1365-2478.13551
Loading
Assessing the impact of pore‐fracture structures on permeability sensitivity in tectonic coal using computerized tomography scanning
Geophysical Prospecting 72, 2772 (2024); https://doi.org/10.1111/1365-2478.13551
/content/journals/10.1111/1365-2478.13551
/content/journals/10.1111/1365-2478.13551
Loading

Data & Media loading...

  • Article Type: Research Article
Keyword(s): micro computerized tomography; permeability prediction; petrophysics; pore‐fracture structure; shape factor

Most Cited This Month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error