Bit type | IADC Code | Applicable formation | Main characteristics of the bit | Recommended parameters | |
Cutting structure | Normal WOB KN/mm(bit dia.) | Rotary Speed(rpm) | |||
THJT117 | 117 | Very soft with low compressive strength and high drillability, such as soft shale,clay,salt bed etc. | Hardfaced gage and all tooth surfaces,and the gage fitted with compacts for enhanced gage protection. And a row of trimmers is added between gage row and heel row. | 0.30-0.90 | 300-80 |
THJT127 | 127 | Soft with low compressive strength and high drillability.such as shale.clay salt bed and soft limestone,etc. | Hardfaced gage and all tooth surfaces,and the gage fitted with compacts for enhanced gage protection. And a row of trimmers is added between gage row and heel row. | 0.50-1.05 | 300-80 |
THJT137 | 137 | Soft to medium soft with low compressive strength or soft with harder stringers such as hard shale,soft limestone and sandstone,etc. , | Hardfaced gage and all tooth surfaces,and the gage fitted with compacts for enhanced gage protection. And a row of trimmers is added between gage row and heel row. | 0.35-0.90 | 300-80 |
THJT417 | 417 | Long section of soft with low comressive strength and high drillability,such as shale,clay,sandstone, Soft with low compressive strength ,such as shale,clay,sandstone,and conglomerate ,etc. | Large radius,offset crested scoop compacts in inner row,wedge compacts in outer row ,high compact exposure and inequable spaced compacts arrangement., And a row of trimmers is added between gage row and heel row. | 0.35-0.90 | 280-70 |
THJT437 | 437 | Very 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.. And a row of trimmers is added between gage row and heel row. | 0.35-0.90 | 280-60 |
