SUBSURFACE SAFETY VALVE Russian patent published in 2014 - IPC E21B34/06 

FIELD: oil and gas industry.

SUBSTANCE: invention is related to oil industry and can be used for well bore shut-off during workover without well killing. The device contains a packer with a body, a shut-off device with a collet equipped with leaves and a head, a control mechanism for the shut-off device, a rod with openings and a circular bore. The rod is equipped with the return valve cage in the upper part, a ring piston in the medium part and a control mechanism as a stepped ring piston at the lower end pressed by a screw and equipped with a sleeve with a collar forming a flexible joint with extension connected to the body; the latter is made as a split casing and at the point of its parts splitting it is equipped with a dividing nut and the lower adapter. The stepped ring piston is equipped with a shell forming a flexible joint in the bore of the lower adapter and a ring chamber with extension connected hydraulically by a drainage outlet with the shell axial channel. Cavities over the ring piston and the collar are connected hydraulically to a cavity over the packer by openings. A cavity of the ring chamber over the dividing nut is connected to the axial channel of the rod by an opening. At that the shaped screw is connected to the body of a by-pass valve having the mounting surface at the butt-end part faced to the baffle collar of the lower adapter wherein in its axial channel there is a saddle with the spring-mounted ball valve, the collet is installed in the split casing. Total cross-section area of the stepped ring piston and collar is accepted equal to the cross-section area of the by-pass valve.

EFFECT: ensuring closure of subsurface safety valve before operation on pump replacement, maintaining working efficiency of the closed subsurface safety valve at any change of pressure drop.

2 dwg