Chemistry and Technology of Fuels and Oils

, Volume 55, Issue 3, pp 319–330 | Cite as

Improved Model for Characterization of Fractal Features of the Pore Structure in a High-Rank Coalbed Methane Formation

  • Jianxun Jiang
  • Jingguo Du
  • Yongqing Wang
  • Fenglin Wang
  • Kun Feng
  • Chunpeng Leng

In this paper, we propose a theoretically derived improved model for characterizing the fractal features of coalbed methane reservoirs, and we compare with previously published models for conventional reservoirs. The model was verified by mercury intrusion porosimetry. The results have shown that there is no linear relationship between the normalized wetting phase saturation, wetting phase saturation, or mercury saturation vs. the capillary pressure on a log-log plot. Therefore existing models are inapplicable for a high-rank CBM formation, which is characterized by low permeability and porosity. The improved model lets us calculate the multi-interval fractal features characterizing the physical properties of the formation. We show that higher fractal dimensions mean poorer physical properties of the formation.


fractal dimensions model for parameter calculation porous structure high-rank coalbed methane formation improved model mercury intrusion porosimetry 


This study was financially supported by the National Foundation for Science and Technology Special Projects of China: Research Projects in Technology, Geological Survey Equipment, and Coalbed Methane Production (2016ZX-5042-004).


  1. 1.
    H. M. Jia, Q. J. Hu, Z. Liu, et al., “Influence of fractures stress sensitivity on water production law for the single-phase flow of CBM wells and drainage countermeasures,” China Coalbed Methane, 14, No. 5, 31-34 (2017).Google Scholar
  2. 2.
    C. L. Li, Z. Y. Peng, and S. Y. Zhu, “ Coalbed methane is adsorption gas underground,” Lithologic Reservoirs, 25, No. 2, 112-115, 122 (2013).Google Scholar
  3. 3.
    X. X. Lu, W. H. Hang, Y. P. Chen et al., “Pore structure of deep coal seam in southern Qinshui basin,” Journal of Northeast Petroleum University, 39, No. 3, 41-49 (2015).Google Scholar
  4. 4.
    X. F. Ma, S. C. Zhang, and Z. X. Lang, “Calculation of fractal dimension of pore structure by using subsection regression method,” Journal of the University of Petroleum, China (Natural Science Edition), 28, No. 6, 54-56 (2004).Google Scholar
  5. 5.
    R. H. Brooks and A. T. Corey, “Hydraulic properties of porous media,” Colorado State University Hydrology Papers, 72-80 (1964).Google Scholar
  6. 6.
    K. W. Li, “Analytical derivation of Brooks - Corey type capillary pressure models using fractal geometry and evaluation of rock heterogeneity,” Journal of Petroleum Science and Engineering, 73, 20-26 (2010).CrossRefGoogle Scholar
  7. 7.
    C. Z. He and M. Q. Hua, “Fractal geometry description of reservoir pore structure,” Oil & Gas Geology, 19, No. 1, 15-23 (1998).Google Scholar
  8. 8.
    K. W. Li and R. N. Home, “Fractal characterization of the geysers rock,” Geothermal Resources Council Trans., 27 (2003).Google Scholar
  9. 9.
    K. W. Li, “Characterization of rock heterogeneity using fractal geometry,” in: SPE International Thermal Operations and Heavy Oil Symposium and Western Regional Meeting, Bakersfield, California USA, March 16-18 (2004), SPE 86975.Google Scholar
  10. 10.
    Y. Yang, H. S. Sun, X. D. Peng et al., “Quantitative study on fractal characteristics of the structure of CBM reservoir,” Special Oil and Gas Reservoir, 20, No. 1, 31-33, 88 (2013).Google Scholar
  11. 11.
    H. M. Jia, “The fractal feature of the pore structure for high coal rank coal porous media,” Journal of Petrochemical Universities, 29, No. 1, 53-56, 85 (2016).Google Scholar
  12. 12.
    B. Y. Jiang, B. Q. Lin, H. J. Wu et al., “Modeling and simulation of speed control system based on high-speed on-off valve,” Journal of Hunan University of Science & Technology (Natural Science Edition), 25, No. 3, 15-18, 28 (2010).Google Scholar
  13. 13.
    P. C. Liu, Z. Yuan, and K. W. Li, “An improved capillary pressure model using fractal geometry for coal rock,” Journal of Petroleum Science and Engineering, 145, 473-481 (2016).CrossRefGoogle Scholar
  14. 14.
    B. B. Mandelbrot, The Fractal Geometry of Nature, W. H. Freeman, San Francisco (1982).Google Scholar
  15. 15.
    K. W. Li, “Characterization of rock heterogeneity using fractal geometry,” SPE 86976 (2004).Google Scholar

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© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  • Jianxun Jiang
    • 1
  • Jingguo Du
    • 1
    • 2
  • Yongqing Wang
    • 1
  • Fenglin Wang
    • 3
  • Kun Feng
    • 3
  • Chunpeng Leng
    • 2
  1. 1.College of Oil and Natural Gas EngineeringSouthwest Petroleum UniversityChengduChina
  2. 2.College of Mining EngineeringNorth China University of Science and TechnologyChengduChina
  3. 3.China United Coalbed Methane Corporation, LtdBeijingChina

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