Reverse tooth hole opener is specially designed and customized for Horizontal directional drilling.
In HDD project, construction sides pay large attention to drill speed. Because it will affect drill cost per meter. But what will affect drilling speed? Tooth shape or IADC code of roller bits is very important factor.
Below is the common IADC code and tooth shape:
- IADC437 ,spoon inserts/chisel inserts, very soft formations
- IADC517 , spoon inserts, soft formations
- IADC537, spoon inserts/chisel inserts, medium formations
- IADC547,conical inserts, medium formations
- IADC637, conical inserts/conispherical inserts, hard formations
- IADC637 can drill hard rocks, but the tooth is short, the drill speed is slower than long tooth.
- IADC437 drill faster, but the tooth is very long, the risk of tooth broken is higher than short tooth.
So there is best tooth shape, but most suitable tooth shape.
Therefore, when we choose pilot bit, if the rocks are not too hard, it’s better to choose IADC 537 as far as possible. The drilling speed is faster.
When we choose hole opener, we have to notice the tooth direction. The roller bits of trenchless hole opener is developed from oil drilling. In petroleum drilling industry, the rotary direction of roller bits are clockwise. But roller bits of hole opener is counter rotation. For spoon inserts, the tooth own two sides, “edge” and “back of knife”. In counter rotation, it’s back to crush rocks. The efficiency will decrease a lot.
Therefore, when we choose hole opener, either we choose IADC637(conispherical inserts), or choose 547(conical inserts).Both of them is symmetric shape. It should be noted that most IADC 537 is spoon inserts in the market.
According to market research, no mater formations is soft, medium or hard, most users choose IADC 637.In their experience, drilling speed of IADC 537 maybe slower than 637.It also reflects another fact. In the market, there may be rare factories or even zero, who develop customized tooth for Horizontal directional drilling.
Solidkey produce Reverse tooth hole opener and roller bits for customers. The spoon inserts crush rocks by their edges. Drilling speed is must faster in pebble bed and medium formations. The drilling cost is lower. When you need, please contact us.