IADC

WOB

(KN/mm)

RPM

(r/min)

Applicable Formations

114/116/117

0.3~0.75

180~60

Very soft formations with low compressive strength and high drillability,

124/126/127

0.3~0.85

180~60

Soft formations with low compressive strength and high drillability,

134/135/136/137

 0.3~0.95

150~60

Soft to medium formations with low compressive strength and high drillability, 

214/215/216/217

0.35~0.95

150~60

Medium formations with high compress strength, 

227

  0.35~0.95

150~50

Medium hard formations with high compressive strength,

Note: The upper limits of WOB and RPM in above table should not be used simultaneously.

IADC

WOB

(KN/mm)

RPM

(r/min)

Applicable Formations

417/437/

 447/415/435

0.35~0.9

150~70

Very soft formations with low compressive strength and high drillabilityetc.

517/527/515

0.35~1.0

140~60

Soft formations with low compressive strength and high drillability,

537/547/535

 0.45~1.0

120~50

Soft to medium formations with low compressive strength,.

617/615

0.45~1.1

90~50

Medium hard formation with high compress strength, 

637/635

  0.5~1.2

80~40

Hard formations with high compressive strength, 

Note: The upper limits of WOB and RPM in above table should not be used simultaneously.