Scholarlink

<p>The long-term productivity of shale reservoirs depends on the stability of fracture conductivity under complex in situ stress conditions. This study investigates the anisotropic permeability evolution of shale fractures under true triaxial cyclic loading, examining the effects of bedding orientation and fracture type. The results indicate that permeability degradation is governed by the full 3D stress tensor. In addition to direct normal compression, the anisotropic Poisson effect triggered by parallel stress loading induces lateral matrix expansion, causing distinct "hidden" fracture closure. A pronounced contrast was observed between fracture types: while hydraulic fractures retained residual conductivities exceeding 0.003 mD due to asperity self-propping, natural fractures undergo severe mechanical closure, with permeability decreasing by over five orders of magnitude (0.42mD–1.86 nD). Mechanistic analysis reveals that macroscopic volumetric compaction (&gt; 0.6%)—driven by shear-induced asperity crushing rather than dilation—governs irreversible permeability damage. Consequently, a true triaxial stress-angle constitutive model was established. By decoupling directional stiffness degradation from the poroelastic matrix response, the model accurately reproduces permeability evolution and confirms the exponential correlation between the aperture closure and permeability recovery ratios, ranging from 24 to 96%. This study provides a solid theoretical basis for fracturing design and production forecasting in deep shale gas development.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Effect of Dip Angle on Permeability of Hydraulic Rough Fractures During Shale Reservoir Depletion and Shut-in Recovery: insights from True Triaxial Loading–Unloading Tests

  • 期刊论文

  • 发表日期：

    2026年5月26日

查看全文
  • Jiaxin Zhu,
  • Tianyu Chen,
  • Dawei Deng,
  • Yu Wang,
  • Xueyan Jiang,
  • Zhiguo Wang,
  • Yunlong Fu,
  • Jiyuan Lu,
  • Hongming Zhang,
  • Zhejun Pan

摘要

The long-term productivity of shale reservoirs depends on the stability of fracture conductivity under complex in situ stress conditions. This study investigates the anisotropic permeability evolution of shale fractures under true triaxial cyclic loading, examining the effects of bedding orientation and fracture type. The results indicate that permeability degradation is governed by the full 3D stress tensor. In addition to direct normal compression, the anisotropic Poisson effect triggered by parallel stress loading induces lateral matrix expansion, causing distinct "hidden" fracture closure. A pronounced contrast was observed between fracture types: while hydraulic fractures retained residual conductivities exceeding 0.003 mD due to asperity self-propping, natural fractures undergo severe mechanical closure, with permeability decreasing by over five orders of magnitude (0.42mD–1.86 nD). Mechanistic analysis reveals that macroscopic volumetric compaction (> 0.6%)—driven by shear-induced asperity crushing rather than dilation—governs irreversible permeability damage. Consequently, a true triaxial stress-angle constitutive model was established. By decoupling directional stiffness degradation from the poroelastic matrix response, the model accurately reproduces permeability evolution and confirms the exponential correlation between the aperture closure and permeability recovery ratios, ranging from 24 to 96%. This study provides a solid theoretical basis for fracturing design and production forecasting in deep shale gas development.