1. Features
Composite screen is composed of base pipe, composite sand control filtering sleeve and external protective stainless steel sleeve. Base pipe is API standard casing or tubing, and sand control filtering sleeve is made of stainless steel precision micropore composite filtering material in all-welded structure. Composite sand control filtering sleeve is characterized by high penetrability, high strength, high non-deformability, high reliability and effective corrosion resistance, marking a new and high-performance product for mechanical sand control.
A. Filtering.
1. Double-precision design of sand control sleeve: punched sleeve is used for external protective sleeve to filter large sand grains and the multiple composite sand control filtering layer is designed for internal sand control layer. Such structure improves the sand control reliability, but also the jamming-resisting capability..
2. External protective sleeve with bridge-type side flow ports: the filtering layer can be effectively protected in the hole and during service, to avoid direct corrosion damage of fluids to the filtering layer and to prolong its service life.
3. Multiple composite sand control filtering layer.
■ Multiple 316L stainless steel precision micropore composite sand control filtering layer has high sand control reliability and strong survivability..
■ Large filtering area is 3 ~ 5 times as much as slotted screen and wire wrapped screen with small resistance to flow and high production..
■ Stable filtering ports, strong non-deformability, and sand control capability is not changed if radial deformation is 40%, which meets the requirement for the horizontal well..
■ Uniform filtering ports, high penetrability, strong jamming resistance and for ease of back washing.
B. Integrated filtering sleeve ring: minimize the welding frequency for the filtering structure and base pipe, eliminating the effect of welding on the overall screen strength.

C. Changeable screen filtering structure: multiple combinations of filtering materials can be realized subject to realities, to meet the field service requirements.

D. Its O.D. is smaller than that of equivalent casing collar, with good tripping-in performance.

2. Improvements
Along with the development of oil exploration and development technology and the ocean hydrocarbon resources, the directional wells, horizontal wells, cluster wells, multilateral wells and other complicated options are becoming popular, brining higher technical requirements for sand control screen.
■ Thin screen wall, large inside diameter, small resistance and high production..
■ It can bear great bending deformation and round to ellipse without failure of sand control..
■ High sand control reliability, no sand leaking hole, high strength of mesh, long sand control filtering sleeve and small seams..
■ Large seepage area and small resistance to flow..
■ Resistance to acid, brine and CO2 corrosion..
■ it can effectively solve the problems such as sand production of fine silt and sand production in thermal recovery of heavy oil.
The conventional screen filtering structure is simple, not reliable in sand control and less applicable, and often result in screen jamming or failure of formation sand control due to improper sand control precision, so it is far from the need of completion technology.

3. Application.
Now, it is effectively used in various oilfields at home (e.g. Xinjiang, Tuha, Jilin, Daqing and Huabei oilfields) and abroad (e.g. Sudan, Russia, South America and Middle East).

4. Specifications.
Specifications for some composite screens.