SHOE-VALVE FOR SHANK Russian patent published in 2011 - IPC E21B17/14 E21B34/12 

FIELD: oil and gas industry.

SUBSTANCE: shoe-valve for shank, which includes housing with central pass in which there arranged is seat with valve closing when it is supported by the bottomhole. Besides, seat is rigidly fixed relative to the housing which is equipped below the seat with non-tight guide bushing, and from below it is equipped with annular constriction; at that, valve made in the form of plug is equipped from below with the pusher spring-loaded downwards relative to the guide bushing and having the possibility of restricted movement upwards relative to the guide bushing and annular constriction till the valve tightly interacts with the seat. At that, central pass of the housing below the seat is interconnected with external space.

EFFECT: simple and reliable design of the shoe, tight covering of the bottom of the column during the operation.

1 dwg