IADC

WOB(kN/mm)

RPM(r/min)

Formation

114115

0.3-0.75

180-50

Soft formation with low compressive strength and high drillability,such as  mudstone,clay,chalk,etc

116117

0.3-0.8

150-70

Soft formation with low compressive strength and high drillability,such as  mudstone,clay,chalk,etc

124125

0.3-0.85

180-60

Soft formation with low compressive strength and high drillability,such as  mudstone,clay,salt,loose stands,soft limestone,etc

126127

0.3-0.9

150-60

Soft formation with low compressive strength and high drillability,such as  mudstone,clay,salt,loose stands,soft limestone,etc

134135

0.35-0.95

150-50

Soft to medium formation with low compressive strength or soft with harder streaks,such as  mudstone,shale,soft limestone ,sands,etc

136137

0.35-1.0

120-60

Soft to medium formation with low compressive strength or soft with harder streaks,such as  mudstone,shale,soft limestone ,sands,etc

214215

0.4-0.95

150-60

 medium  hard formation with high compressive strength ,such as  medium soft shale,anhydrite,medium soft limestone ,medium soft sandstone as well as thick and hard streaks,etc

216217

0.4-1.0

100-60

medium  hard formation with low compressive strength ,such as  medium soft shale,limestone and sandstone as well as thick and hard streaks,etc

244

0.35-0.95

150-50

medium  hard formation with high compressive strength ,such as  hard shale,sands ,limestone,etc

246247

0.4-1.0

80-50

medium  hard formation with high compressive strength ,such as  hard shale,sands ,limestone,etc

324325

0.4-1.0

120-50

hard formation with  high strength and abrasiveness such as hard limestone,hard sands,dolomite,hard shale,etc