Arabian Journal of Geosciences

, 12:562 | Cite as

Modified SLD model for coalbed methane adsorption under reservoir conditions

  • Xiaojun WuEmail author
  • Zhengfu NingEmail author
  • Guoqing Han
  • Qing Wang
  • Ziyao Zhong
  • Rongrong Qi
  • Zhilin Cheng
  • Liang Huang
Part of the following topical collections:
  1. Geo-Resources-Earth-Environmental Sciences


In the process of coalbed methane (CBM) mining, with the decreasing of reservoir pressure, stress sensitivity and matrix desorption shrinkage, which could be called self-regulating effect comprehensively, possess great effect on the gas adsorption due to the changing of pore volume. Therefore, it is necessary to modify the simplified local density (SLD) model to investigate the gas adsorption under reservoir conditions for an accurate prediction of CBM production. For the utilization of SLD adsorption model, assume the pores as slit pore. When pressure is lower than critical desorption pressure and keeps falling, the deformations of specific surface area (SSA) and pore width could be studied by the chosen Shi and Durucan (S&D) model. Furthermore, based on the variation relationship and the modification of SLD model, a new adsorption predicting model could be derived with the consideration of stress sensitivity, and matrix desorption shrinkage. In the absence of stress sensitivity and matrix desorption shrinkage, the calculated consequence is relatively smaller than the actual field adsorption data. What’s more, the sensitivity analyses of Poisson’s ratio, pore volume compressibility and critical desorption pressure are conducted with the application of this new model. At the same reservoir pressure, Poisson’s ratio possesses negative relationship with modified adsorption, while pore volume compressibility and critical desorption pressure both possess positive influence on modified adsorption. The main reason is that Poisson’s ratio affects matrix desorption shrinkage negatively, while pore volume compressibility and critical desorption pressure affect matrix desorption shrinkage positively. In spite of the opposite effect of stress sensitivity and matrix desorption shrinkage on pore deformation, matrix desorption shrinkage exhibits a dominant role in self-regulating.


CBM Adsorption Self-regulating SLD 


Funding information

This work was supported by the National Natural Science Foundation of China (Grants No. 51774298, No. 51974330, and No. 51574256)


  1. Bangham DH (1937) The Gibbs adsorption equation and adsorption on solids. Trans Faraday Soc 33:805–811CrossRefGoogle Scholar
  2. Busch A, Gensterblum Y, Krooss BM, Siemons N (2006) Investigation of high-pressure selective adsorption/desorption behaviour of CO2 and CH4 on coals: an experimental study. Int J Coal Geol 66:53–68. CrossRefGoogle Scholar
  3. Chen JH, Wong DSH, Tan CS, Subramanian R, Lira CT, Orth M (1997) Adsorption and desorption of carbon dioxide onto and from activated carbon at high pressures. Ind Eng Chem Res 36:2808–2815. CrossRefGoogle Scholar
  4. Chen D, Pan Z, Liu J, Connell LD (2013) An improved relative permeability model for coal reservoirs. Int J Coal Geol 109:45–57. CrossRefGoogle Scholar
  5. Dahaghi AK (2010) Numerical simulation and modeling of enhanced gas recovery and CO2 sequestration in shale gas reservoirs: a feasibility study. In: SPE international conference on CO2 capture, storage, and utilization. Society of Petroleum Engineers.
  6. Fitzgerald J, Sudibandriyo M, Pan Z, Robinson R Jr, Gasem K (2003) Modeling the adsorption of pure gases on coals with the SLD model. Carbon 41:2203–2216. CrossRefGoogle Scholar
  7. Foo KY, Hameed BH (2010) Insights into the modeling of adsorption isotherm systems. Chem Eng J 156:2–10CrossRefGoogle Scholar
  8. Golden TC, Sircar S (1994) Gas adsorption on silicalite. J Colloid Interface Sci 162:182–188CrossRefGoogle Scholar
  9. Harpalani S, Schraufnagel RA (1990) Shrinkage of coal matrix with release of gas and its impact on permeability of coal. Fuel 69:551–556. CrossRefGoogle Scholar
  10. Huang L, Ning Z, Wang Q, Ye H, Chen Z, Sun Z, Sun F, Qin H (2018a) Enhanced gas recovery by CO 2 sequestration in marine shale: a molecular view based on realistic kerogen model. Arab J Geosci 11:404. CrossRefGoogle Scholar
  11. Huang S, Yao Y, Zhang S, Ji J, Ma R (2018b) Pressure transient analysis of multi-fractured horizontal wells in tight oil reservoirs with consideration of stress sensitivity. Arab J Geosci 11:285. CrossRefGoogle Scholar
  12. Jiang Z, Zhao L, Zhang D (2018) Study of adsorption behavior in shale reservoirs under high pressure. J Nat Gas Sci Eng 49:275–285. CrossRefGoogle Scholar
  13. Lee LL (1988) Molecular thermodynamics of nonideal fluids. ButterworthsGoogle Scholar
  14. Ma Q, Harpalani S, Liu S (2011) A simplified permeability model for coalbed methane reservoirs based on matchstick strain and constant volume theory. Int J Coal Geol 85:43–48CrossRefGoogle Scholar
  15. Mao X, Liu Y, Guan W, Liu S, Li J (2018a) A new effective stress constitutive equation for cemented porous media based on experiment and derivation. Arab J Geosci 11:337. CrossRefGoogle Scholar
  16. Mao X, Liu Y, Guan W, Yueli F (2018b) Experimental and numerical simulation on the influence of anisotropic fracture network deformation to shale gas percolation. Arab J Geosci 11:615. CrossRefGoogle Scholar
  17. Mavor M, Vaughn J (1998) Increasing coal absolute permeability in the San Juan Basin fruitland formation. SPE Reserv Eval Eng 1:201–206. CrossRefGoogle Scholar
  18. Palmer I, Mansoori J (1996) How permeability depends on stress and pore pressure in coalbeds: a new model. SPE Reserv Eval Eng 1:539–544. CrossRefGoogle Scholar
  19. Peng Z, Li X (2018) Improvements of the permeability experiment in coalbed methane. Arab J Geosci 11:259. CrossRefGoogle Scholar
  20. Qi R, Ning Z, Wang Q, Zeng Y, Huang L, Zhang S, Du H (2018) Sorption of methane, carbon dioxide, and their mixtures on shales from Sichuan Basin, China. Energy Fuel 32:2926–2940CrossRefGoogle Scholar
  21. Sheng G, Javadpour F, Su Y (2018) Effect of microscale compressibility on apparent porosity and permeability in shale gas reservoirs. Int J Heat Mass Transf 120:56–65CrossRefGoogle Scholar
  22. Shi J, Durucan S (2004) Drawdown induced changes in permeability of coalbeds: a new interpretation of the reservoir response to primary recovery. Transp Porous Media 56:1–16. CrossRefGoogle Scholar
  23. Shi J-Q, Durucan S (2005) A model for changes in coalbed permeability during primary and enhanced methane recovery. SPE Reserv Eval Eng 8:291–299. CrossRefGoogle Scholar
  24. Zhao M, Yao z XM, Li J, Xu J (2013) Dynamic permeability model considering self-adjustment effect for coalbed methane. Fault-Block Oil Gas Field 1:63–66Google Scholar

Copyright information

© Saudi Society for Geosciences 2019

Authors and Affiliations

  1. 1.State Key Laboratory of Petroleum Resources and ProspectingChina University of Petroleum (Beijing)BeijingChina
  2. 2.Department of Petroleum EngineeringChina University of Petroleum (Beijing)BeijingChina

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