drilling Concentric Overburden drilling systems Reamer Bit,Overburden Reamer

Application Range: It is suitable for drilling water wells , geothermal wells , short miscopies ,medium mini-type grouting hole of building , dam and harbor project .

1. Ring bit and casing shoe assembly is separated, the casing shoe is threaded to casing tube to drilling. Lock the assembly into pilot bit with hammer. The pilot bit's upper shoulder engages the shoulder of the casing shoe.

2. Hammer's percussive energy is transferred through the pilot and ring bits, crushing rock . Part of impact energy advances casing.

3. On completion of drilling and casing , the drill string with pilot bit is retrieved by a slight reverse rotation to unlock the bayonet coupling . The ring bit stays in the hole , and can be recovered only if the casing is retrieved

4. Drilling continues to the desired depth in the bedrock using a conventional drilling.