西南石油大学学报(自然科学版) ›› 2019, Vol. 41 ›› Issue (5): 127-133.DOI: 10.11885/j.issn.1674-5086.2018.08.28.02

Previous Articles     Next Articles

Calculation Model of Shale Gas Adsorption Capacity Under Supercritical Conditions

ZHAO Jun1, LIU Kai1, YANG Lin2, HE Yufei2   

  1. 1. School of Geosciences and Technology, Southwest Petroleum University, Chengdu, Sichuan 610500, China;
    2. Evaluation Center, Logging Co. Ltd., CNPC, Xi'an, Shaanxi 710000, China
  • Received:2018-08-28 Online:2019-10-10 Published:2019-10-10

Abstract: Shale gas adsorption capacity is a key parameter in determining the development value and life of shale gas wells. The existing Langmuir isotherm adsorption model for the adsorption of monolayers is not suitable for the reservoir conditions of shale gas in China. Therefore, the main factors affecting shale gas adsorption capacity were studied by isothermal adsorption experiments at different temperatures and fitting of the isothermal adsorption curves. The analysis shows that the main factors are formation temperature and pressure, porosity, organic matter content and maturity, and mineral composition and content (including clay minerals as direct factors). Based on the Polanyi adsorption theory, a quantitative calculation model of shale gas adsorption that considers temperature, pressure, porosity, organic matter content and maturity, and mineral composition and content was constructed. The calculation results are consistent with the results of the analysis of gas content from on-site core sampling. The new model considers supercritical adsorption, which compensates for the shortcomings of the monolayer adsorption model that is currently in use, and has important practical significance for shale gas adsorption capacity calculation.

Key words: shale gas, isothermal adsorption, polanyi adsorption theory, supercritical adsorption, quantitative calculation

CLC Number: