BORE-PIECE CHOKE SHUTOFF VALVE Russian patent published in 2019 - IPC E21B34/14 E21B43/12 

FIELD: mining.

SUBSTANCE: invention relates to well shutoff valves. Downhole choke shutoff valve is fixed on the tubing string and includes a valve body with a seat for installation of a self-contained downhole instrument, a valve unit having a flapper with a hold-down spring, a movable tube with side holes for liquid intake and an annular recess in the upper part, a return spring and a housing with choke channels of different cross-section. Device is controlled by a set of fixing devices lowered on rope equipment and representing collets. Chamfer grippers have protruding teeth on cantilever spring supports, engaged with annular recess on movable tube, as well as deflecting ledges interacting with the baffle plate on the chassis housing and releasing the projecting teeth from engagement with the annular groove on the movable tube. Working condition of choke shutoff valve depends on movable tube movement when it is lifted by collet gripper, at that, by successive operations of lowering different collet grips, valve gate closing is performed, and then communicating the inner cavity of the device with the annular space of the well when side holes are aligned on the movable tube with one of the union channels on the union body. Movable tube displacement value till collet grip release moment is determined by distance between protruding teeth and deflectors on consoles of used collet grip.

EFFECT: technical result consists in improvement of bottom-hole shutoff valve efficiency.

1 cl, 1 dwg