A good driller should always be clear about the type and strength of the geology being drilled, what kind of drilling tools to apply and what drilling method is the most effective, so that the load can be minimized, the wear and tear minimized, and the progress maximized.

 

The drilling methods of rotary drilling rigs can be divided into four types according to the geological conditions: cutting, crushing, toggling and grinding.

 

I. Cutting type

 

Cutting drilling uses bucket teeth and double-bottom sand bucket with friction type drill pipe to drill into the strata with low resistance, such as mud layer, powder and sand layer with geological strength within 400 kPa.

 

II. Crushing type

 

In most cases, double-bottom rock-entry buckets are used for crushing drilling, which can be equipped with friction or machine-locked drilling rods according to the geological strength, and can drill into sand and gravel, mudstone, sandstone, shale and medium weathering with the strength of 500 kPa to 1000 kPa.

 

III. Toggling type