Hole opener

Large-diameter assembled bit is widely used in construction, bridge, highway and railway construction. This series of bits are suitable to various kinds of strata including shale, limestone, cobblestone, dolomite and conglomerate.

1.Suitable for medium to medium hard formation of high Crushing Resistanc

(hard shale,sands,etc.)    

2.Bit bearing is non-sealed roller bearing.

3.Hardfacing is applied on the shirttail,and carbide inserts for gage protection

are pressed into the head OD.

4.Cone gage surface is reinforce with carbide compacts. 

1.Cutting Structure

In response to the characteristics that inserts in different areas on the cone have different cutting actions, conical inserts are placed in permanent contact area and wedge inserts are placed in alternative contact area so that the drilling efficiency is greatly improved. Wear resistance of cutting structure is enhanced by setting diamond inserts in the permanent contact area of the cone where inserts are severely worn. Tungsten carbide inserts are placed on cone top face to protect cone body from abrasive erosion.

2. Gauge Structure

With active cutting gauge protection inserts on bit body, the bit has good gauge protection and up drill capability.

3.Bearing Structure

High precision journal bearing. Balls lock the cone.Hardface heard bearing surface. Cone bearing inlaid with friction-reducing alloy. Abrasion resistance and seizure resistance of the bearing are improved. Compared with three cone bit, the leg bearing is bigger, so it can receive higher WOB and high reliability.

4.Hydraulic Design

Small angled watercourse design increased the shirttail thickness and can effectively prevent the watercourse erosion.Optirnized hydraulics structure improves the clearing capability and increases ROP.

5. Product Application

It is suitable for sidetracking, deep well drilling and old well repairing.