| |||
| 井底覆盖 | |||
| 钻头与孔底接触面积 | |||
| |||
| 钻头与井底接触面积; 钻头齿圈对井底覆盖程度 | |||
| 对井底覆盖程度 | |||
|
bottom-hole coverage : 4 phrases in 2 subjects |
| Drilling | 1 |
| Oil / petroleum | 3 |
| |||
| 井底覆盖 | |||
| 钻头与孔底接触面积 | |||
| |||
| 钻头与井底接触面积; 钻头齿圈对井底覆盖程度 | |||
| 对井底覆盖程度 | |||
|
bottom-hole coverage : 4 phrases in 2 subjects |
| Drilling | 1 |
| Oil / petroleum | 3 |