Advanced Drilling Methods for Water Well Drill Rods & Diamond Bits

For hard formations, diamond drill bits are the only effective drilling solution. Here are the correct operating methods for water well drill rods and diamond drill bits:

1. Follow the “Five No-Sweeping Rules”:
Do not use diamond bits to sweep the hole, remaining core, fallen core, collapsed debris, or probing stones.

Follow the “Three Must-Pull Rules”:
Pull out the drill string immediately when encountering resistance, core blockage, or a sudden drop in drilling speed.

2. If the drill bit slips during drilling, never force drilling by increasing pressure or allowing dry drilling. Stop and pull out the drill string for inspection immediately.
3. Use reduced-pressure drilling. Straighten the drill string before rod removal, and slightly lift the tools off the hole bottom before restarting to prevent bit damage under heavy load.
4. Prepare the required rod length before lowering the drill string. During drilling, do not lift the tools off the bottom to add drill rods.
5. In complex formations, raise the drilling tools slowly while continuously pumping flushing fluid to prevent hole collapse caused by suction.

6. New drill bits must undergo an “initial grinding” process to improve formation adaptability, smooth the bit face, remove sharp edges, and expose impregnated diamonds.

Method:
Begin with light pressure (about 1/3 of normal pressure) and slow rotation (around 100 rpm). After drilling 0.2–0.3 m, gradually increase to normal speed. Keep the first drilling run short and inspect the bit wear in time.