GEAR TO SEPARATE SAND FROM STRATAL FLUID IN WELL DURING ITS OPERATION Russian patent published in 2003 - IPC

FIELD: operation of wells of various assignment, predominantly in oil fields complicated by sand manifestation. SUBSTANCE: gear is intended for separation of stratal fluid from sand. Gear includes lifting string located under intake of well pump and sand pockets installed in sequence over length of lifting string. Each pocket is formed by internal surface of lifting string, external surface of bushing placed inside lifting string and bridge. The latter couples rigidly lower part of external surface of bushing to internal surface of lifting string. Length of each bushing amounts to 0.30-0.75 distance between bridges. Flow conduit of each bushing is larger than flow conduit of well pump and amounts to 0.2-0.8 inner diameter of lifting string. EFFECT: raised functional reliability of gear due to its simplification, uniformity in filling of pockets or priority filling of lower pockets, prolonged operation time of well with reliable cleaning of stratal fluid from sand. 16 cl, 1 dwg