IADC

WOB

RPM

Applicable Formations

(KN/MM)

(r/min)

(Bit Dia)

116  117

0.35~0.8

150~80

Very soft formations with low compressive strength and high drillability,such as clay,mudstone,chalk etc.

126  127

0.35~0.9

150~70

Soft formations with low compressive strength and high drillability,such as mudstone ,gypsum,salt,soft shale.soft limestone,etc.

136  137

0.35~1.0

120~60

Soft to mesium soft formations with low compressive strength and high drillability.such as medium soft shale,hard gypsum,medium soft limestone.medium soft sandstone soft formation with harder interbeds, etc.

216  217

0.4~1.0

100~60

Medium hard formations with high compressive strength,such as medium soft shale,hard gypsum,medium soft limestone,medium soft sandstone,soft formation with harder interbeds etc.

246  247

0.4~1.0

80~50

Medium hard formations with high compressive strength,such as abrasive shale.limestone,sandstone,dolomite,hard gypsum,marble,etc.

417  437

0.35~0.9

150~70

Very soft formations with low compressive strength and high drillability,such as clay,mudstone,chalk,gypsum,salt,soft shale,soft limestone,etc.

447

517  527

0.35~1.0

140~60

Soft formations with low compressive strength and high drillability,such as mudstone,gypsum,salt,soft shale.soft limestone,etc.

537  547

0.45~1.0

120~50

Soft to medium formations with low compressive strength,such as medium soft shale,medium soft limestone,medium soft sandstone,medium formation with harder and abrasiver interbeds,etc.

617  627

0.45~1.1

90~50

Medium hard formations with high compressive strength,such as hard shale,limestone,sandstone,dolomite,etc.

637

0.5~1.2

80~40

Hard formations with high compressive strength,such as sandstone,limestone,dolomite,hard gypsum,marble,etc.