BACK VALVE SWITCHED BY FLOW Russian patent published in 2009 - IPC E21B34/08 

FIELD: mining.

SUBSTANCE: back valve switched by flow consists of body, of guiding element with passing through it opening, also this element is installed inside body, and of valve gate with head and rod. The head has upper along flow surface interacting with seating surface of the body, when the valve gate is in the first position. A finger passes into a groove so, that it follows the shape of the groove at displacement of valve gate inside the body. The shape of the groove facilitates the valve gate travel from the first position to the second one at applying force to the head and from the second position to the third one when the head is not subject to force, also the third position is located below along flow relative to the first position. Depending on the shape of the groove of the valve and on number of valves there is possible to create various versions of circulation without applying valve systems or without round trip operations.

EFFECT: flexibility of fluid circulation in well.

30 cl, 6 dwg