SELF-CLEANING WELL SCREEN Russian patent published in 2007 - IPC E21B43/08 

FIELD: mining, particularly screens or liners used during oil and well operation.

SUBSTANCE: self-cleaning filter comprises concentrically arranged outer, central and inner pipes. Central and inner pipes have orifices and connected with each other through connection pipe in upper parts thereof. Outer pipe ends are attached to intermediate one by means of annular caps. Inner pipe has filtering member arranged within the limits of inner pipe zone provided with orifices. The pipe zone has bell member and longitudinal ribs connected thereto. The bell member is spaced from intermediate pipe and comprises centralizer and nozzle installed in lower part thereof. Filtering member is inserted in annular space between inner and intermediate pipes and is coaxial thereto. The filtering member is made as inverse truncated cone and is fastened to the pipes over upper orifices provided in the pipes. Central orifices of intermediate pipe are opposite to bell member and are provided with filtering member.

EFFECT: increased mechanical impurities trapping capacity and prevention of filtering member clogging.

4 dwg