136 Micro-Nano Scale Pore-Fracture Architecture and Fluid Dynamics in Shale and Coal Reservoirs

The exploration and development of shale and coal reservoirs are pivotal to modern unconventional fossil energy production. The intricate micro-nano scale pore-fracture architecture within these reservoirs significantly influences storage capacity, fluid occurrence, and migration dynamics.

Monday, 20 October 2025
1:30 PM - 5:30 PM
HBGCC, 302C

The Pore-Fracture Evolution and Fluid Transport Behavior in Terrestrial Shales under In-Situ Subsurface Conditions

Paper number: 136-12
Program: Technical Sessions
Time: 4:35 PM – 4:50 PM

Authors

  • Yue Jiao Presenting Author
    Research Institute of Petroleum Exploration and Development, Beijing
  • Bin Bai
    Research Institute of Petroleum Exploration and Development, Beijing
  • Chang Liu
    Research Institute of Petroleum Exploration and Development, Beijing
  • Lin Ma
    The University of Manchester, Manchester
  • Xiulin Hou
    Research Institute of Petroleum Exploration and Development, Beijing

Abstract

To visualize and evaluate the effectiveness of shale bedding fractures under subsurface temperature and pressure conditions, dynamic experiments and simulations on shale samples are required. Micrometer-Computerized Tomography (μm-CT) technology was utilized to conduct high-resolution in-situ four-dimensional image characterization on selected samples under varying temperatures and pressures, enabling quantitative and comparative analysis of changes in the pore-fracture networks. By simulating the interaction between subsurface fluids and the pore-fracture system, the behavior of shale oil under realistic subsurface temperature and pressure conditions is predicted. During heating, the volume of organic pores and fractures in organic-rich shale increases, but stabilizes beyond a certain temperature. Under pressurization, longitudinal fractures in shale samples gradually decrease, while transverse fractures first expand and then shrink. Samples with higher brittle mineral content may generate new fractures during pressurization, leading to fluctuations in the total fracture volume, though the overall trend is a reduction. Shale permeability exhibits anisotropy and generally decreases with increasing pressure. The permeability remains largely unchanged under brine and CO2 injection conditions. These findings provide a critical foundation for advancing theories on shale fluids prediction and enhance the evaluation of reservoir space distribution and connectivity under realistic geological conditions.

Key words: organic-rich shale, μm CT technology; shale pore-fracture networks; in-situ four-dimensional imaging characterization; fluid behaviour evaluation

Geological Society of America Abstracts with Programs. Vol. 57, No. 6

doi: 10.1130/abs/2025AM-413983

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