| Permeability | High | Medium | Low | ||||||||||||
| Sand & Gravel (not combined) | Separated gravel | Separated sand, sand & gravel | Fine grain sand, mud (sill) & clay |
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| Combined Rock | Rock with most fractured | Oil reservoir rock | Sandstone | Limestone, Dolomite | Granite | ||||||||||
| k (cm2) | 10−3 | 10−4 | 10−5 | 10−6 | 10−7 | 10−8 | 10−9 | 10−10 | 10−11 | 10−12 | 10−13 | 10−14 | 10−15 | ||
| k (millidarcy) | 108 | 107 | 106 | 105 | 104 | 103 | 100 | 10 | 1 | 0.1 | 0.01 | 10−3 | 10−4 | ||