Research Article
Cocompetitive Characteristics and Quantitative Design of Engineering Parameters for Coal Gas Predrainage Boreholes
Table 1
Basic parameters of gas extraction simulation.
| | Parameter | Value | Parameter | Value |
| | Young’s modulus of coal (, MPa) | 2813 | Initial permeability of coal fracture (, m2) | | | Young’s modulus of coal grains (, MPa) | 8439 | Normal atmospheric pressure (, MPa) | 0.101325 | | Fracture strength of coal (, MPa) | 4800 | Langmuir pressure constant (, MPa) | 0.922 | | Poisson’s ratio of coal () | 0.339 | Langmuir volume constant (, m3/kg) | 0.023 | | Density of coal (, kg/m3) | 1250 | Langmuir volumetric strain constant () | 0.01266 | | Initial porosity of the coal matrix () | 0.05 | Dynamic viscosity of methane (, N·s/m2) | | | Initial permeability of coal matrix (, m2) | | Density of methane at standard condition (, kg/m3) | 0.717 | | Initial gas pressure of coal seam (, MPa) | 1.9 | Air leakage (, m/s) | |
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