| Dynamic fluid viscosity | High perm | Medium perm | Low perm | Tight (Shale) |
|---|
| cP | > 100 md | 10 md ÷ 100 md | 0.1 md ÷ 10 md | < 0.1 md |
|---|
| Low viscous oil | < 1 |
|
|
|
|
|---|
| Medium viscous oil | 1 ÷ 10 |
|
|
|
|
|---|
| High viscous oil | 10 ÷ 100 |
|
|
|
|
|---|
| Extra high viscous oil | 100 ÷ 10,000 |
|
|
|
|
|---|
| Bitumen | > 10,000 |
|
|
|
|
|---|
where box colours mean:
and the ranges of properties in the table are only tentatively define the category based on the industry statistics and conventions, which vary over history and locations. | 