DOWNHOLE CIRCULATION VALVE Russian patent published in 2022 - IPC E21B34/10 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry and is intended for connection and isolation of annular space of a well with inner cavity of a pipe string during development and killing of wells, during treatment and other well operations. Downhole circulation valve comprises a housing with circulation holes, a rod installed inside the housing with possibility of axial movement. In upper part of housing there are hydraulic channels connected from above with hydraulic lines for supply of control fluid to rod, which forms upper and lower annular cavities with housing. One hydraulic channel is connected to the lower annular cavity, and the other one — to the upper annular cavity. When fluid is supplied to one hydraulic line, the rod moves upwards, opening circulation holes of the housing, and when liquid is supplied to the other hydraulic line, it moves downwards, closing circulation holes of the housing. Rod is pressed by a spring through a collet, which in the initial closed position of the valve rests against the upper collar on the outer surface of the rod and is clamped from the outside by the bushing, fixing the valve in the closed position. Collet is installed with possibility of axial movement and disengagement from upper collar of rod when it moves upwards under action of control fluid and engagement with lower collar on external surface of rod for fixation of valve in open position.

EFFECT: providing communication and isolation of annular space of the well with internal cavity of the pipe string by means of supply of control fluid along a hydraulic line with fixation of the valve in open and closed positions.

1 cl, 2 dwg