China Petroleum Exploration ›› 2018, Vol. 23 ›› Issue (1): 100-108.DOI: 10.3969/j.issn.1672-7703.2018.01.011

• PETROLEUM GEOLOGY • Previous Articles     Next Articles

Study on the applicability of adsorption models to shale Gas

He Ran1,2, Li Zhiping1,2, Lai Fengpeng1,2, Tang Xuan1,2   

  1. 1 School of Energy Resources, China University of Geosciences(Beijing);
    2 Beijing Key Laboratory of Unconventional Natural Gas Geology Evaluation and Development Engineering, China University of Geosciences(Beijing)
  • Received:2017-03-17 Revised:2017-06-12 Online:2018-01-15 Published:2018-01-04
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Abstract: The adsorption characteristics of shale gas have great influence on its reserves prediction, seepage mechanism analysis and productivity evaluation. The adsorption model is one of the principal methods to describe shale gas adsorption characteristics. So far, scholars at home and abroad have different opinions on the selection of adsorption models for shale gas. It is revealed that the applicability of adsorption models to shale gas is not understood clearly. To solve this problem, the applicability of four common adsorption models (i.e., Langmuir model, BET model, D-R model and half pore width model) to shale gas was studied thoroughly by fitting the adsorption models to the experimental data of methane isothermal adsorption on shale. And the following research results were obtained. First, neither Langmuir model nor BET model considers the adsorption energy level difference of active sites on the surface of shale pores, so their fitting errors are larger when the pressure is lower. Second, D-R model considers the ultrahigh adsorption in the interval of low pressure, so it is only applicable to the shale possessing more micro pores. Third, half pore width model takes into consideration the adsorption potential theory and the pore diameter distribution of shale comprehensively, and it is well fitted with the experimental data. And fourth, the fitting errors between four common adsorption models and experiment data of methane isothermal adsorption on shale in Fuxian area of the Ordos basin are ranked from the low to the high, i.e., half pore width model, Langmuir model, BET model and D-R model.

 

Key words: shale gas, adsorption model, isothermal adsorption, applicability

CLC Number: