• 全国中文核心期刊
  • 中国科技核心期刊
  • 美国工程索引(EI)收录期刊
  • Scopus数据库收录期刊
肖智勇, 王长盛, 王刚, 蒋宇静, 于俊红. 基质-裂隙相互作用对渗透率演化的影响:考虑基质变形和应力修正[J]. 岩土工程学报, 2021, 43(12): 2209-2219. DOI: 10.11779/CJGE202112007
引用本文: 肖智勇, 王长盛, 王刚, 蒋宇静, 于俊红. 基质-裂隙相互作用对渗透率演化的影响:考虑基质变形和应力修正[J]. 岩土工程学报, 2021, 43(12): 2209-2219. DOI: 10.11779/CJGE202112007
XIAO Zhi-yong, WANG Chang-sheng, WANG Gang, JIANG Yu-jing, YU Jun-hong. Influences of matrix-fracture interaction on permeability evolution: considering matrix deformation and stress correction[J]. Chinese Journal of Geotechnical Engineering, 2021, 43(12): 2209-2219. DOI: 10.11779/CJGE202112007
Citation: XIAO Zhi-yong, WANG Chang-sheng, WANG Gang, JIANG Yu-jing, YU Jun-hong. Influences of matrix-fracture interaction on permeability evolution: considering matrix deformation and stress correction[J]. Chinese Journal of Geotechnical Engineering, 2021, 43(12): 2209-2219. DOI: 10.11779/CJGE202112007

基质-裂隙相互作用对渗透率演化的影响:考虑基质变形和应力修正

Influences of matrix-fracture interaction on permeability evolution: considering matrix deformation and stress correction

  • 摘要: 研究煤储层的渗透率对于合理开采煤层气等能源的适用性和可行性都有指导意义。目前,大量的渗透率模型是基于弹性应变和吸附应变建立。然而,这些模型在考虑这两种应变时常把基质当作刚性体,并认为吸附变形完全由裂隙开度调节。在预测渗透率时不仅忽略了基质变形,还高估了吸附膨胀的影响。为此,提出了一个新的渗透率模型来预测不同边界条件下的储层渗透率。该模型提出内部膨胀系数f来修正基质吸附对裂隙开度及外部应力的影响,且考虑了有效应力对裂隙和基质的变形行为。为比较基质变形和应力修正对渗透率的影响,对比不考虑应力修正的模型和不考虑基质本身变形的模型,用现场数据和实验室数据对不同边界条件下3种渗透率模型进行验证。结果表明:应力修正在单轴应变条件时对渗透率演化的影响更加显著,且不考虑应力修正和基质本身变形的模型所得的内部膨胀系数f较大。最后,进一步将新模型和4种经典模型进行比较,再次说明了新模型的优越性。

     

    Abstract: Studying the permeability of coal seam is of guiding significance for the applicability and feasibility of rational mining of coalbed methane and other energy sources. A large number of current permeability models are established based on the elastic and adsorption strains. However, these models often treat the matrix as a rigid body and assume that the adsorption deformation is fully regulated by the fracture aperture when considering these two strains. The matrix deformation is neglected in predicting permeability, and the effect of adsorption swelling is also overestimated. Therefore, a new permeability model is proposed to predict reservoir permeability under different boundary conditions. The model proposes an internal expansion coefficient f to correct the effects of matrix adsorption on fracture aperture and external stress, and considers the deformation behavior of the fracture and matrix under the effective stress. To compare the effects of matrix deformation and stress correction on permeability, the three models for permeability under different boundary conditions are validated through the field data and laboratory data by comparing the model without considering stress correction and the model without considering the deformation of the matrix itself. The results show that the stress correction has a more significant effect on the permeability evolution under uniaxial strain, and that the model without consideration of both the stress correction and the deformation of the matrix will obtain higher internal expansion coefficient f. Finally, the proposed model is further compared with four classical models to illustrate again its superiority.

     

/

返回文章
返回