Table 1 Parameter selection table.
Parameter type | Symbol | Unit | Value | Parameter name | Symbol | Unit | Value |
|---|---|---|---|---|---|---|---|
Duct area | \(A_{O}\) | m2 | 0.0133 | Drill pipe diameter | \(d\) | m | 0.56 |
Drill pipe area | \(A_{1}\) | m2 | 0.25 | Drill pipe length | \(H_{t}\) | m | 30 |
Mud area of slurry return tank | \(A_{2}\) | m2 | 0.4 | Buried depth of air duct | \(H_{j}\) | m | 24 |
Slag content1 | \(\alpha_{s}\) | – | 5% | Mud viscosity | \(\mu\) | Pa·s | 0.16 |
Slag content2 | \(\alpha_{s2}\) | – | 3% | Bit rotation speed | \(w\) | r/min | 8 |
Gas rate | \(\alpha_{g2}\) | – | 43% | Bit taper | \(\theta\) | ° | 35 |
Mud density | \(\rho_{l}\) | kg/m3 | 1100 | Bit diameter | \(D\) | m | 5 |
Rock debris density | \(\rho_{s}\) | kg/m3 | 2300 | Bottom hole height | \(h\) | m | 0.56 |
Gas density | \(\rho_{g}\) | kg/m3 | 1.29 | Mud displacement | \(Q\) | m3/s | 1.04 |
Rock debris diameter | \(d_{s}\) | m | 0.03 | wind pressure | \(p\) | MPa | 0.4 |
