Research Article
Numerical Modeling on Hydraulic Fracturing in Coal-Rock Mass for Enhancing Gas Drainage
Table 3
Parameters for the numerical calculation.
| | Material parameters | Values | Material parameters | Values |
| | Elastic modulus E | 3.35 GPa | Initial permeability k0 | 3 × 10−18 m2 | | Poisson’s ratio | 0.33 | Initial porosity | 0.05 | | Uniaxial compressive strength fc | 40 MPa | Residual porosity | 0.01 | | Internal friction angle φ | 30° | Water dynamic viscosity μw | 3.55 × 10−4 Pa·s | | Uniaxial tensile strength ft | 3 MPa | Bulk modulus of water βl | 2.5 GPa | | Homogeneity index m | 1.5 | Biot coefficient α | 0.8 | | Langmuir coefficient a1 | 4 × 10−2 m−3·kg−1 | Langmuir coefficient a2 | 8 × 103 Pa−1 | | Coal density ρs | 1.25 × 103 kg·m−3 | Compressibility coefficient of gas β | 1.18 × 10−5 kgPa−1·m−3 | | Gas dynamical viscosity μg | 1.84 × 10−5 Pa·s | Initial gas pressure pw | 2.1 MPa |
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