Numerical simulation of the influence of pore microstructures and mineral composition on the mechanical properties of shale under uniaxial compression

Zhenlin Wang^1*Hongyan Qi¹Kai Feng²Rong Zhang¹Qingyong Luo³

• ¹Xinjiang Oilfield Company, Karamay, China
• ²Peking University, Beijing, China
• ³China University of Petroleum Beijing, Changping, China

With the intensifying demand for global energy, unconventional resources—particularly shale oil and gas—have become focal targets for exploration and development. In this study, numerical simulations were employed to systematically examine how pore‐scale microstructural attributes (porosity, pore radius, and distribution) and mineralogical composition influence the mechanical response of shale under uniaxial compression. The results demonstrate that peak compressive strength is highly sensitive to variations in pore distribution, whereas the elastic modulus remains comparatively stable across different pore configurations. Analysis of fractal dimensions further reveals a negative correlation with both peak strength and modulus, highlighting the role of structural complexity in weakening mechanical performance. In addition, increasing pore radius and porosity lead to a progressive reduction in average peak strength; notably, larger pore radii exacerbate the disparity between maximum and minimum strength values across distributions, while porosity exerts a less pronounced effect. Orthogonal statistical tests indicate that mineralogy exerts the dominant control on peak compressive strength, followed by pore radius, with porosity showing the weakest influence. Collectively, these findings emphasize the critical importance of microstructural heterogeneity and mineral composition in governing the mechanical behavior of shale reservoirs, and provide theoretical guidance for reservoir stability assessments and unconventional resource development.