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Investigation of coal pore and fracture distributions and their contributions to coal reservoir permeability in the Changzhi block, middle-southern Qinshui Basin, North China

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Abstract

Pores and fractures in coal have an important influence on gas desorption, diffusion, and seepage during coalbed methane (CBM) recovery. The occurrence and spatial distribution of pores and fractures in the Changzhi CBM block coals of the middle-southern Qinshui Basin, North China, were investigated by means of scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and low-temperature liquid nitrogen isotherm adsorption/desorption (LT-N2AD). In addition, pore and fracture contributions to the permeability of the coal reservoir were evaluated. The results show that there are many pores and fractures with different widths and lengths in the coals, most of which are isolated. The microfractures serve as a bridge for gas migration between pores, cleats, and macrofractures. Based on the relationship between cross-cutting microfractures and cleats, the multiple populations of microfractures in the coals can be classified as 1st class and 2nd class microfractures. Statistical analyses reveal that the aperture distributions of these fractures are heterogeneous and that the expected fracture aperture distributions can be described by a log-normal Gaussian function. Based on the statistically expected fracture aperture and its actions on gas flow, three levels of potential flow paths and three permeability domains are concluded to occur in coal reservoirs, including cleats, 1st class microfractures, and 2nd class microfractures. For this study area, due to the occurrence of mineralized cleats, the CBM reservoir permeability is significantly reduced. The current coal reservoir permeability contribution is mostly from the 1st class and 2nd class microfractures. Lastly, based on the pore and fracture spatial distributions of the coal and the three statistically expected permeability domains, the coupled pore-fracture network configuration models of coal reservoirs were constructed, which are useful for evaluating coal reservoir permeability.

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References

  • Bustin RM (1997) Importance of fabric and composition on the stress sensitivity of permeability in some coals, Northern Sydney Basin, Australia: relevance to coalbed methane exploration. AAPG 81:1894–31908

    Google Scholar 

  • Cai YD, Liu DM, Yao YB, Li JG, Qin YK (2011) Geological controls on prediction of coalbed methane of No.3 coal seam in Southern Qinshui Basin, North China. Int J Coal Geol 88:101–112

    Article  Google Scholar 

  • Chinese National Standard GB/T 30050-2013 (2013) Classification of coal-body structure. Standards Press of China, Beijing, pp 1–8

  • Clarkson CR, Bustin RM (1999) The effect of pore structure and gas pressure upon the transport properties of coal: a laboratory and modeling study. 1. Isotherms and pore volume distributions. Fuel 78:1333–1344

    Article  Google Scholar 

  • Frodsham K, Gayer RA (1999) The impact of tectonic deformation upon coal seams in the South Wales coalfield, UK. Int J Coal Geol 38:297–332

    Article  Google Scholar 

  • Gamson PD, Beamish B, Johnson DP (1993) Coal microstructure and micropermeability and their effects on natural gas recovery. Fuel 72:87–99

    Article  Google Scholar 

  • Gamson PD, Beamish B, Johnson DP (1996) Coal microstructure and secondary mineralization: their effect on methane recovery. In: Gayer R, Harris I (eds) Coalbed methane and coal geology. Geological Society London Special Publications, London, pp 165–179

    Google Scholar 

  • Golab A, Ward CR, Permana A, Lennox P, Botha P (2013) High-resolution three dimensional imaging of coal using microfocus X-ray computed tomography, with special reference to modes of mineral occurrence. Int J Coal Geol 113:97–108

    Article  Google Scholar 

  • Hower JC, Dai SF (2016) Petrology and chemistry of sized Pennsylvania anthracite, with emphasis on the distribution of rare earth elements. Fuel 185:305–315

    Article  Google Scholar 

  • IUPAC (International Union of Pure and Applied Chemistry) (1994) Physical chemistry division commission on colloid and surface chemistry, subcommittee on characterization of porous solids. Recommendations for the characterization of porous solids (Technical Report). Pure Appl Chem 66:1739–1758

    Article  Google Scholar 

  • Jiang B, Qu ZH, Wang GGX, Li M (2010) Effects of structural deformation on formation of coalbed methane reservoirs in Huaibei coalfield, China. Int J Coal Geol 82:175–183

    Article  Google Scholar 

  • Kakei K, Ozeki S, Suzuki T, Kaneko K (1990) Multi-stage micropore filling mechanism of nitrogen on microporous and micrographitic carbons. J Chem Soc Faraday Trans 86:371–376

    Article  Google Scholar 

  • Laubach SE, Marrett RA, Olson JE, Scott AR (1998) Characteristics and origins of coal cleat: a review. Int J Coal Geol 35:175–207

    Article  Google Scholar 

  • Li H, Ogawa Y, Shimada S (2003) Mechanism of methane flow through sheared coals and its role on methane recovery. Fuel 82:1271–1279

    Article  Google Scholar 

  • Lucia FJ (1983) Petrophysical parameters estimated from visual descriptions of carbonate rocks: a field classification of carbonate pore space. J Pet Technol 35:629–637

    Article  Google Scholar 

  • Mazumder S, Wolf KHAA, Elewaut K, Ephraim R (2006) Application of X-ray computed tomography for analyzing cleat spacing and cleat aperture in coal samples. Int J Coal Geol 68:205–222

    Article  Google Scholar 

  • Mohamad NH, Katsuaki K (2015) Coal quality related to microfractures identified by CT image analysis. Int J Coal Geol 140:97–110

    Article  Google Scholar 

  • Moore TA (2012) Coalbed methane: a review. Int J Coal Geol 101:36–81

    Article  Google Scholar 

  • Nie BS, Liu XF, Yang LL, Meng JQ, Li XC (2015) Pore structure characterization of different rank coals using gas adsorption and scanning electron microscopy. Fuel 158:908–917

    Article  Google Scholar 

  • Pan JN, Hou QL, Ju YW, Bai HL, Zhao YQ (2012) Coalbed methane sorption related to coal deformation structures at different temperatures and pressures. Fuel 102:760–765

    Article  Google Scholar 

  • Permana AK (2012) 3-D imaging of cleat and micro-cleat characteristics, south Walker Creek coals, Bowen Basin, Australia: microfocus X-ray computed tomography analysis. Indones J Geogr 7:1–9

    Google Scholar 

  • Permana AK, Ward CR, Li Z, Gurba LW (2013) Distribution and origin of minerals in high-rank coals of the South Walker Creek area, Bowen Basin, Australia. Int J Coal Geol 116:185–207

    Article  Google Scholar 

  • Ren ZL, Hui X, Li LS, Qin Y, Wei CT (2005) Determination of Mesozoic tectonic heat event in Qinshui Basin. Pet Explor Dev 32:43–47 (in Chinese)

    Google Scholar 

  • Sang SX, Liu HH, Li MX, Li L (2009) Geological controls over coal-bed methane well production in southern Qinshui Basin. Prog Earth Planet Sci 1:917–922

    Article  Google Scholar 

  • Scott AR, Kaiser WR, Ayers WB Jr (1991) Composition, distribution, and origin of Fruitland Formation and Pictured Cliffs Sandstone gases, San Juan Basin, Colorado and New Mexico. In: Schwochow SD, Murray DK, Fahy MF (eds) Coalbed methane of Western North America. Rocky Mountain Association of Geologists, Denver, pp 93–108

    Google Scholar 

  • Snow DT (1968) Rock fracture spacings, openings, and porosities. J Soil Mech Found Div Am Soc Civ Eng 94:73–91

    Google Scholar 

  • Solano-Acosta W, Mastalerz M, Schimmelmann A (2007) Cleats and their relation to geologic lineaments and coalbed methane potential in Pennsylvanian coals in Indiana. Int J Coal Geol 72:187–208

    Article  Google Scholar 

  • Ward CR (2002) Analysis and significance of mineral matter in coal seams. Int J Coal Geol 50:135–168

    Article  Google Scholar 

  • Ward CR (2016) Analysis, origin and significance of mineral matter in coal: an updated review. Int J Coal Geol 165:1–27

    Article  Google Scholar 

  • Yao YB, Liu DM (2009) Microscopic characteristics of microfractures in coals: an investigation into permeability of coal. Prog Earth Planet Sci 1:903–910

    Article  Google Scholar 

  • Yao YB, Liu DM, Cai YD, Li JQ (2010) Advanced characterization of pores and fractures in coals by nuclear magnetic resonance and X-ray computed tomography. Sci China Earth Sci 53:854–862

    Article  Google Scholar 

  • Zhang XD, Du ZG, Li PP (2017) Physical characteristics of high-rank coal reservoirs in different coal-body structures and the mechanism of coalbed methane production. Sci China Earth Sci 60:246–255

    Article  Google Scholar 

Download references

Acknowledgments

We are grateful to the PetroChina Huabei Oilfield Company for providing the CBM field data. Also, sincere appreciation is given to the anonymous reviewers for their comments to improve this manuscript and thanks given to Associate Editor Katz and Dr. Chuang Liu at the McGill University of Canada for their language help to improve the readability of this manuscript.

Funding

This work was supported by the National Natural Science Foundation of China (grant number 41372162); Science and Technology Innovation Team Support Plan of Henan Province (grant number 14IRTSTHN002); and Scientific Research Foundation of Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process, Ministry of Education (China University of Mining and Technology) (grant number 2016–2010).

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Authors and Affiliations

  1. School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo, 454000, Henan, China

    Zhigang Du, Xiaodong Zhang, Shuo Zhang & Chenlin Wang

  2. School of Civil Engineering, Luoyang Institute of Science and Technology, Luoyang, 471003, Henan, China

    Zhigang Du & Qiang Huang

  3. Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process, Ministry of Education (China University of Mining and Technology), Xuzhou, 221008, Jiangsu, China

    Zhigang Du

  4. Collaborative Innovation Center of Coalbed Methane (Shale Gas) in Central Plains Economic Zone, Jiaozuo, 454000, Henan, China

    Xiaodong Zhang

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  1. Zhigang Du
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  2. Xiaodong Zhang
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  3. Qiang Huang
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  4. Shuo Zhang
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  5. Chenlin Wang
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Correspondence to Xiaodong Zhang.

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Editorial handling: Barry Katz

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Du, Z., Zhang, X., Huang, Q. et al. Investigation of coal pore and fracture distributions and their contributions to coal reservoir permeability in the Changzhi block, middle-southern Qinshui Basin, North China. Arab J Geosci 12, 505 (2019). https://doi.org/10.1007/s12517-019-4665-9

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  • DOI: https://doi.org/10.1007/s12517-019-4665-9

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