Bit type | IADC Code | Applicable formation | Main characteristics of the bit | Recommended parameters | |
Cutting structure | Normal WOB KN/mm(bit dia.) | Rotary Speed(rpm) | |||
THJ447G | 447 | Soft with low compressive strength and high drillability,such as shale,clay,sandstone,soft limestone,salt bed and gypsolyte,etc. | Large radius offset crested scoop compacts in inner row,wedge compacts in outer row,high compact exposure and inequable spaced compacts arrangement. | 0.35-1.00 | 240-60 |
THJ517G | 517 | Soft with low compressive strength and high drillabilty ,such as shale ,clay ,sandstone and soft limestone,etc. | Large radius offset crested scoop compacts in inner row,wedge compacts in outer row,high compact exposure and inequable spaced compacts arrangement. | 0.35-1.05 | 240-50 |
THJ527G | 527 | Soft with low compressive strength and high drillabilty ,such as shale ,clay ,sandstone and soft limestone,etc. | Large radius offset crested scoop compacts in inner row,wedge compacts in outer row,high compact exposure and inequable spaced compacts arrangement. | 0.35-1.05 | 240-50 |
THJ537G | 537 | Medium soft with low compressive strength and harder abrasive stringers,such as hard shale,hard gypsolyte,soft limestone,sandstone and dolomite with strngers,etc. | Large radius offset crested scoop compacts in inner row,wedge compacts in outer row,high compact exposure and inequable spaced compacts arrangement. | 0.50-1.05 | 220-40 |
THJ547G | 547 | Medium soft with low compressive strength and harder abrasive stringers,such as hard shale,mudstone,soft limestone and sandstone,etc. | Large radius scoop compacts in inner row,wedge compacts in outer row and inequable spaced compacts arrangment. | 0.50-1.05 | 220-40 |
THJ617G | 617 | Medium hard with high compressive strength and thick &hard stringers,such as limestone,hard shale,mudstone and sandstone,etc. | Large radius scoop compacts in inner row,wedge compacts in outer row and inequable spaced compacts arrangment. | 0.50-1.05 | 220-40 |
THJ627G | 627 | Medium hard with high compressive strength and hard stringers ,such as limestone,hard sandy mudstone and sandstone,etc. | Conical compacts in inner row,spherical compacts in outer row. | 0.50-1.05 | 200-40 |
THJ637G | 637 | Medium hard with high compressive strength and abrasiveness ,such as limestone,dolomite and sandstone,etc. | Conical compacts in inner row,spherical compacts in outer row. | 0.50-1.10 | 200-40 |
THJ737G | 737 | Hard formation with high abrasiveness such as hard limestone ,dolomite,hard sandstone and chert,etc. | Large radius,conical compacts in inner row ,spherical compacts in outer row. | 0.50-1.20 | 200-40 |
