TY - JOUR
TI - Experimental analysis and model study on effective stress sensitivity of coal rock permeability
AU - Bi Cai-Qin
AU - Xin Xiao-Lin
AU - Liu Shuang
AU - Cai Cheng-Zheng
AU - Zhu Zheng-Chao
JN - Thermal Science
PY - 2025
VL - 29
IS - 2
SP - 1545
EP - 1550
PT - Article
AB - Using the unsteady pressure drop method, permeability measurements of coal  samples were conducted across various bedding directions under different  effective stresses. Mercury injection, SEM, and micro-CT techniques were  employed to analyze pore/fracture structures. By integrating experimental  data, existing stress-sensitive permeability models were validated and  refined. The results demonstrated that gas permeability in cores from  different directions exponentially correlates with effective stress. During  decompression, the permeability exhibited limited recovery and irreversible  damage. Stress sensitivity assessments with varying parameters indicated  high sensitivity of coal permeability to effective stress, both  perpendicular and parallel to bedding planes. The revised permeability model  predicts permeability with an error margin of less than 15%.