Research Article
Permeability Prediction in Deep Coal Seam: A Case Study on the No. 3 Coal Seam of the Southern Qinshui Basin in China
Table 1
Parameter magnitudes for matching the experimental data.
| Parameter | Value |
| Elastic modulus, (GPa) | 1.12 | Poisson’s ratio, | 0.26 | Bulk modulus, (MPa) | 778 | Matrix modulus, (MPa) | 10340 | Constrained axial modulus, (MPa) | 1369 | Biot’s coefficient, | 0.925 | Initial porosity (for N2), (%) | 0.585 | Initial porosity (for CO2), (%) | 0.42 | Maximum sorption volume (for N2), (m3/t) | 30.05 | Langmuir parameter (for N2), (MPa−1) | 0.07 | Sorption swelling coefficient (for N2), (t/m3) | 4.99 × 10−4 | Langmuir volume (for CO2), (m3/t) | 55.78 | Sorption parameter (for CO2), (MPa−1) | 0.48 | Sorption swelling coefficient (for CO2), (t/m3) | 9.30 × 10−4 | Effective coal matrix deformation factor, | 0.1723 | Empirical parameter for P-M model, | 0.1 | Matrix compressibility, (MPa−1) | 9.67 × 10−5 | Fracture compressibility, (MPa−1) | 0.013 | Initial fracture compressibility, (MPa−1) | 0.3422 | Decline rate of fracture compressibility with increasing effective stress, (MPa−1) | 2.65 × 10−14 |
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