HOLE FILTER Russian patent published in 1998 - IPC

FIELD: devices used in wells including oil, gas water and cleaning wells. SUBSTANCE: hole filter includes elongated flexible filter element wound in form of coil. Filter element contains filtering cloth in form of tape with elongated bearing rods located in parallel relative to each other at preset gaps and wires in form of rods located transversely relative to bearing rods to which they are welded. Filter may be additionally provided with elongated flexible perforated tube whose openings are located at preset gaps; tubular element is located over its outer periphery. Thus, smooth surface of coil is obtained during manufacture of filter with no difficulty in winding the filter. EFFECT: enhanced efficiency of filtration. 4 cl, 6 dwg