Pre-packed Screen

　　Precise Gravel Pre-packed Screen is an excellent combination of the central liner (in line with the API casing&tubing) 、precision punching shroud and gravel. and the filtration jackets are divided into two kinds: inner jackets and outer jackets.  They are welded onto the perforated base pipe through end ring. The interspaces between two filtration jackets are filled in standard gravel. In application, the formation sand can not easily enter the filtration jacket while the formation fluid can easily flow into screen through space between punched slots. Sand control is achieved.

the Precision of the filtration for Gravel

Class of Precision of Filtration	1	2	3
Gravel Diameter，μm	450-224	450-900	900-1250
Precision of Filtration，μm	70-35	70-140	140-200