WATER FILTER OF WELL DRILLED IN FINE AND SILTY SANDS Russian patent published in 2010 - IPC E03B3/18 E21B43/04 

FIELD: process engineering.

SUBSTANCE: invention relates to construction of water wells operated in water-bearing formations consisting of fine and silty sands. Water well filter drilled in fine and silty sands comprises gravel packing, external perforated well casing and inner string with filtration layer, shoe and packing. External perforated well casing is equipped with additional filtration element representing, for example a screen with pass holes with diametre equal to gravel packing particle size, and settling device. Size of inner string filtration element pass holes equals that of water-bearing sand particles, said filtration element representing multilayer spooling from polymer threads. Note here that inner string shoe incorporates waterproof plug.

EFFECT: increased operation of well at sufficient extraction rate due to less intensive plugging of filtration element during water filtration, ease and high rate of filter replacement.

1 dwg