Research Article
Permeability Enhancement Technology for Soft and Low-Permeability Coal Seams Combined with Hydraulic Perforation and Hydraulic Fracturing
Table 1
Physical and mechanical parameters.
| | Stratum | Thickness (m) | Density (KN/m3) | Bulk modulus (GPa) | Shear modulus (GPa) | Cohesion (MPa) | Angle of internal friction (°) | Tensile strength (MPa) |
| | Roof | 6 | 24 | 45 | 11.3 | 3.6 | 21 | 3.8 | | Coal seam | 6 | 14 | 0.2 | 0.04 | 0.8 | 19 | 0.32 | | Floor | 6 | 24 | 35 | 9.5 | 4.2 | 28 | 5.2 |
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