WELL SCREEN (VERSIONS) Russian patent published in 1997 - IPC

FIELD: oil, gas and water wells, particular, screen for well to assist in placement in the needed point of well of filter medium. SUBSTANCE: well screen includes longitudinal supporting members. They form cylindrical surface with gaps between supporting members. Wound on the outer surface on supporting member is wire to form gaps between its coils. Well screen has, at least, one channel for supply of gravel-containing suspension. It is made with holes for gravel through the preset intervals over the channel length. Holes communicate the channel hollow with ambient medium. Channel is located from the inner side of wire winding, in addition, the device has cylindrical perforated member which together with wire coils forms hollows of annular space between the inner surface of wire coils and outer surface of cylindrical perforated member. Well screen also has sealing units. They are installed for provision of communication of hollows of annular space over the screen length and formation of longitudinal channel for supply of gravel-containing suspension. Channel has holes for gravel. Besides, the well screen has filtering case. It is made in form of tube with slots. EFFECT: higher efficiency of lowering and lifting of well screen in the well. 17 cl, 22 dwg