PDC bits have become the main bit type in water well drilling, oil & gas drilling, and geological exploration due to their high wear resistance, high drilling efficiency, and long service life. However, many field personnel have misconceptions in use, leading to premature bit failure. This article shares practical experience from two aspects: use points and daily maintenance.
Key Points for Correct Use of PDC Bits
1. Reasonable Selection According to Formation: Soft to medium-hard formations (mudstone, sandstone, shale) use medium-density, large cutters (13-16mm); hard and abrasive formations use small cutters (8-11mm), high-density layout, and reinforced gauge.
2. Strictly Control Drilling Parameters: WOB should not be too large. Soft formations: 20-60kN; hard formations: 80-120kN. RPM: soft formations 80-150r/min, hard formations 40-80r/min. Pump rate: generally 10-15L/min per inch of bit diameter.
3. Smooth Feed and Avoid Impact Load: Avoid sudden weight application and stop-start operations to prevent cutter breakage.
Daily Maintenance
- Clean cuttings and mud from the bit immediately after pulling out of the hole.
- Inspect cutter wear, missing cutters, and matrix cracks.
- Store in a dry environment away from moisture and impact.
- Repair or replace worn cutters in time.
