Multilayer well screens pipes are used for oil and water exploiting.
Characteristics:
~ They consist of two screens or multilayer screen
~ Perforated pipe inside ,with perforations wrapped by the outside Johnson type screen
~ The screen jacket and base pipe are welded together with a length of coupling.
~ The base pipe can be made of seamless pipe or welded pipe,and more often,casing pipes.
~ ID of Johnson type screen equals OD of the perforated pipe
Aquifer classification | gravel | grit | Medium sand | Silve sand | silt |
screening | 1-2.5 | 0.5-1 | 0.25-0.5 | 0.1-0.25 | 0.1-0.25 |
Bridge's slot | 3 | 1.5-2 | 1 | 1 | 0.75 |
Filling gravels specifications | 4-20 | 2-8 | 2-3 | 2-3 | 2-3 |
Friling gravels thickness | 75-100 | 100 | 100-200 | 100-200 | 100-200 |