| IADC |
WOB |
RPM |
Application |
| (KN/mm) |
(r/min) |
| 111/114/115 |
0.3-0.75 |
200-80 |
Very soft formations with low compressive strength and high drill
Ability, like clay, mudstone, chalk |
| 116/117 |
0.35-0.8 |
150-80 |
Very soft formations with low compressive strength and high drill
Ability, like clay, mudstone, chalk |
| 121 |
0.3-0.85 |
200-80 |
Soft formations with low compressive strength and high drill
Ability, like mudstone, gypsum, salt, soft limestone |
| 124/125 |
180-60 |
| 131 |
0.3-0.95 |
180-80 |
Soft to medium formations with low compressive strength,
like medium, soft shake, medium soft limestone, medium soft sandstone, medium
Formation with harder and abrasive interbeds |
| 136/137 |
0.35-1.0 |
120-60 |
| 211/241 |
0.3-0.95 |
180-80 |
Medium formations with high compressive strength, like
Medium, soft shake, hard gypsum, medium soft limestone, medium soft sandstone,
Soft formation with harder interbeds. |
| 216/217 |
0.4-1.0 |
100-60 |
| 246/247 |
0.4-1.0 |
80-50 |
Medium hard formation with high compressive strength, like hard shale,
Limestone, sandstone, dolomite |
| 321 |
0.4-1.0 |
150-70 |
Medium abrasive formations, like abrasive shale, limestone,
Sandstone, dolomite, hard gypsum, marble |
| 324 |
0.4-1.0 |
120-50 |
| 437/447/435 |
0.35-0.9 |
240-70 |
Very soft formations with low compressive strength and high drill
Ability, like clay, mudstone, chalk, gypsum, salt, soft limestone |
| 517/527/515 |
0.35-1.0 |
220-60 |
Soft formations with low compressive strength and high drill ability,
like mudstone, gypsum, salt, soft limestone |
| 537/547/535 |
0.45-1.0 |
220-50 |
Soft to medium formations with low compressive strength, like medium,
Soft shake, medium soft limestone, medium soft sandstone, medium formation with
Harder and abrasive interbeds |
| 617/615 |
0.45-1.1 |
200-50 |
Medium hard formation with high compressive strength, like hard shale,
Limestone, sandstone, dolomite |
| 637/635 |
0.5-1.1 |
180-40 |
Hard formation with high compressive strength, like limestone,
Sandstone, dolomite, hard gypsum, marble |
| Note:
above limitts of WOB and RRPM should not be used
Simultaneously |