Eccentric Overburden Drilling Equipment DTH Pilot Bits

Eccentric Overburden Drilling Equipment DTH Pilot Bits

In the projects of drilling,drillers often meet with problems due to the loose land formation.These may cause troubles such as difficulty in drilling down,collapse of holes,damage of drilling tools,etc.To solve the problems,the best way is to use (ODEX)Overburden Drilling System which can prevent holes and drilling tools from damage,and support the holes by casing tubes.


Application:
Drilling of waterwells, geothermal wells, short micro piles, medium mini-type grouting hole of building, dam and harbour project etc.

General Introduction: 
1.drill in overburden unstable rock 
2.one step to drill and follow casing 
3.flexible to open or close 
4.effecient below 300mm 

Design Principles:
Make the casing follow easy and the equipment and operation simple 
Outstanding Advantages 
Simple structure,simple operation,reliable quality,retrievable drilling tools,long service life.

 
Raw Material: 
Steel: first class special alloy steel with high strength, heat resistance and wearable
Carbide: The best tungsten carbides from China are commonly applied.
Tungsten carbide from European is also available.


Operation Procedure:
1. When drilling starts, the reamer swings out and reams the pilot-hole wide enough for the casing tube to slide down behind the drill bit assembly.  
2. When the required depth is reached, rotation is reversed carefully, whereupon the reamer swings in , allowing the drill bit assembly to be pulled up through the casing.  
3. Casing tubes that are to be left in the drill hole should be sealed at the bottom of the hole by means of cement grout or some other sealing agent. 
4. Drilling continues to the desired depth in the bedrock using a conventional drill string.