DTH Overburden Drilling
When drilling in lose , Unconsolidated so-called overburden formation such as soil, clay,slit,sand and boulders. which varies in depth from a few centimeters to hundreds of meters. It is difficult to retrieve the drill strings after the hole has been drilled, the bore hole is often lost before a casing tube can be inserted to support it.
Eccentric drilling system so called Odex system method is based on a pilot and eccentric reamer,which together drill a hole larger than the external diameter of the casing tube. This enables casing tube follow the drill bit down the hole.
ODEX drilling steps:
- When Drilling starts, the ODEX reamer swings out and reams the pilot hole wide enough for the casing tube to slide down behind the drill bit assembly
- When the required depth reached, rotation reversed carefully, whereupon the reamer swings in allowing, the drill bit assembly to pulled up through the casing.
- Casing tubes that are to be left in the drill hole should be sealed at the bottom of the hole by means cement grout or some other sealing agent
Odex Technical SpecificationOur Next Post: Drifter Bits
