WELLHEAD SEALING DEVICE IN CASE OF POLISHED ROD BREAKAGE Russian patent published in 2021 - IPC E21B33/03 E21B34/02 

FIELD: oil industry.

SUBSTANCE: invention relates to the oil industry, in particular to locking devices used in oil extraction by sucker rod pumps. The proposed device for sealing the wellhead in the event of a polished rod breakage comprises a body, a spring-loaded movable locking plate, located perpendicular to the axis of the polished rod, which can be moved under the action of a spring into a seat. In this case, the locking plate is made in the form of a polyamide disk with a thickness of 2-3 mm and is rigidly connected to the rotary spring and is placed perpendicular to the body axis. The body is made in the form of an inverted cylindrical nozzle with an axial channel for a polished pump rod, with a variable outer diameter, the lower of which of a larger diameter is made with the possibility of rigid connection with the upper cover of the wellhead gland with a self-aligning head. On the upper part, a radial cut is made along the perimeter, which provides the placement and entrance of the movable lock plate and passes into a seat made on the inner surface of the cylindrical body in the form of an annular groove, which provides an abutment in the working position during the lateral movement of the movable lock plate under the action of a rotary spring. The rotary spring is rigidly fixed on the protruding end of the lower part of the housing and is located at the beginning of the radial cutout. Below the seat and the radial cutout inside the body there is a cuff in the form of a disc with a longitudinal hole in the center, coaxial with the hole of the body and a wellhead gland with a self-aligning head, and the density of the cuff material is less than the density of the produced fluid.

EFFECT: invention makes it possible to simplify the design of the device and increase the reliability of overlapping the axial channel when the polished rod breaks during the operation of the pumping unit.

1 cl, 5 dwg