1. Pre-treatment
- Clean the drill pipe threads and the internal threads of the drill bit, and apply special lubricant (such as molybdenum disulfide) to reduce friction and wear.
2. Alignment and Connection
- Align the drill bit vertically with the drill pipe, and manually screw it in 3-5 turns to ensure proper thread engagement and prevent cross-threading.
3. Torque Tightening
- Use a hydraulic wrench to tighten in two stages:
- Initial tightening to 50% of the specified torque (e.g., 7,500 N·m for NC38 threads);
- Final tightening to 100% of the torque (15,000 N·m), referring to the API Spec 7-1 standard.
4. Safety Check
- Mark the threaded joint with a marker pen. Regularly observe whether the marked line shifts during construction to determine if loosening has occurred.
