Scholarlink

<p>This study proposes methane in-situ explosive fracturing (MIEF) for reactivating closed fractures in aging shale gas reservoirs. Employing a split Hopkinson pressure bar (SHPB) system, this study investigates the impact-shearing damage characteristics of the split-re-closed shales. Changes in fracture surface roughness are analyzed via 3D laser scanning, and fracture spaces are reconstructed and quantified using X-ray tomography. Based on numerical simulation methods, the impact-shearing damage process of reclosed fractures is discussed. Results show that rock debris exfoliation during impact shearing reduces fracture surface roughness, with roughness parameters <i>Z</i><sub>2s</sub> and <i>θ</i><sub>max</sub>/(C + 1) exhibiting a linear positive correlation. The 3D box dimension of fracture surfaces decreases after impact shearing and shows an exponential correlation with parameter <i>Z</i><sub>2s</sub>. The 2D box dimension of the damaged areas of the fracture surface displays fractal characteristics and exponential positive correlations with both <i>Z</i><sub>2s</sub> and <i>θ</i><sub>max</sub>/(C + 1). Fracture apertures in split-re-closed shale samples increase by 5–19 times after impact shearing, with the increment positively correlating with roughness parameter <i>Z</i><sub>2s</sub>. Areas with high roughness initiate damage earliest during impact shearing, and periodic “shear dilation – fracture damage” cycles between the upper and lower fracture surfaces lead to (1) non-uniform damage distribution, (2) rock debris exfoliation, and (3) shear misalignment. These effects collectively prevent complete fracture closure, thereby generating self-propping behavior in impact-sheared fractures.</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

Damage characteristic of split-re-closed shale under impact shearing

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年1月28日

查看全文
  • Wei Tang,
  • Cheng Zhai,
  • Ting Liu,
  • Jizhao Xu,
  • Yong Sun,
  • Yangfeng Zheng,
  • Yuzhou Cong,
  • Yu Wang,
  • Chengjian Pi

摘要

This study proposes methane in-situ explosive fracturing (MIEF) for reactivating closed fractures in aging shale gas reservoirs. Employing a split Hopkinson pressure bar (SHPB) system, this study investigates the impact-shearing damage characteristics of the split-re-closed shales. Changes in fracture surface roughness are analyzed via 3D laser scanning, and fracture spaces are reconstructed and quantified using X-ray tomography. Based on numerical simulation methods, the impact-shearing damage process of reclosed fractures is discussed. Results show that rock debris exfoliation during impact shearing reduces fracture surface roughness, with roughness parameters Z2s and θmax/(C + 1) exhibiting a linear positive correlation. The 3D box dimension of fracture surfaces decreases after impact shearing and shows an exponential correlation with parameter Z2s. The 2D box dimension of the damaged areas of the fracture surface displays fractal characteristics and exponential positive correlations with both Z2s and θmax/(C + 1). Fracture apertures in split-re-closed shale samples increase by 5–19 times after impact shearing, with the increment positively correlating with roughness parameter Z2s. Areas with high roughness initiate damage earliest during impact shearing, and periodic “shear dilation – fracture damage” cycles between the upper and lower fracture surfaces lead to (1) non-uniform damage distribution, (2) rock debris exfoliation, and (3) shear misalignment. These effects collectively prevent complete fracture closure, thereby generating self-propping behavior in impact-sheared fractures.