FILTERING WELL CONSTRUCTION METHOD Russian patent published in 2007 - IPC E21B43/04 

FIELD: mining, particularly construction of water or another fluid production wells and to prevent sand production during well completion.

SUBSTANCE: method involves lowering downhole screen connected to flushing pipe provided with flushing bush in well; inwashing gravel filling and removing washed-out particles. Flushing pipe is of double type. Flushing bush comprises telescopically arranged valve with driving unit. The valve has radial channels and closed central channel formed in lower part thereof. Gravel inwashing is carried out when valve is in its closed position and radial valve channel are communicated with downhole screen. Washed-out particles are removed as valve is installed in upper position and radial channels thereof are communicated with well hole annuity through flushing bush.

EFFECT: increased efficiency of drill cuttings and formation sand removal and natural filter forming.

1 dwg, 1 ex