Review Article
A Review of the Evaluation, Control, and Application Technologies for Drill String Vibrations and Shocks in Oil and Gas Well
Table 4
Torsional vibration level classification.
| Level | Stick-slip (/r/min) | State | Limit time |
| Low | 0~40 | Torsional vibration | No | Medium | 40~60 | No | Medium | 60~80 | Suggest reducing vibration | High | 80~100 | Stick-slip | Completely, must reduce vibration | Severe | >100 | Stick-slip | 30 minutes, immediately reduce vibration |
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