Well Completion Strategies for Water Well Drilling Rig in Complex Rock

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Water well drilling rigs need scientific strategies in complex hardness rock formations.water well drilling rig

 

  1. When drilling through sand (f=1) into limestone (f=6), switch from mud to casing support. Casing goes 3m beyond sand layer bottom to prevent collapse.
  2. In alternating soft-hard rocks (shale-sandstone), use “graded drilling”. First drill with Φ130mm bit, then expand with Φ200mm after finding interfaces. Keep mud density 1.2-1.3 for slag carrying and pressure balance.
  3. For quartzite interlayers (f>10), use diamond bits. Follow “light pressure, slow rotation”: 8-10kN feed pressure, ≤400r/min. A water well drilling rig injects 50L lubricant hourly to reduce friction and extend bit life.