FILTERING WELL CONSTRUCTION TOOL Russian patent published in 2006 - IPC E21B33/14 E21B43/04 

FIELD: mining industry, particularly wells for flowable substance production or injection, for well completion during drilling thereof.

SUBSTANCE: tool comprises production and filtering strings, circulation valve having body with flushing channels and shutoff bush, as well as flushing tube with distribution unit and control mechanism for shutoff bush. Shutoff bush may slide inside the flushing channels of the circulation valve body. The shutoff bush is installed on outer surface of circulation valve body and is connected with the body by means of connection dowels. The connection dowels are arranged in flushing channels of circulation valve body and project out of channels to cooperate with the control mechanism. The control mechanism is made as bayonet connection arranged on distribution unit of the flushing tube. The flushing channels may be periodically closed during gravel inwashing.

EFFECT: increased efficiency and provision of controlled technological well construction processes.

2 cl, 1 dwg