PREVENTER Russian patent published in 2004 - IPC

FIELD: oil and gas extractive industry.

SUBSTANCE: device has body with axial channel. Mounted in body are screw-thread dies with drive and compacting elements for pipes pressurization lowered in well through axial channel in body, and moveable roller-vane plate with drive mounted in body for covering axial channel in case of absence of pipes in well. Roller-vane plate is mounted in body separately from screw-thread dies, and is made with possible perpendicular displacement relatively to direction of screw-thread dies displacement and has shape if flat wedge, slanting sides of which are in forced contact with response slanting sides of body of preventer on closed position. Drive of roller-vane plate is made in form of two-stepped screw rigidly fixed from movement along rotation axis. One step of screw is in engagement with roller-vane plate. Another step is in engagement with indicator bushing fixed from rotation by detachable pin placed in fixed groove of body of drive of roller-vane plate. Screw surfaces of two-stepped screw have similar direction of coiling.

EFFECT: higher reliability of preventer.

7 dwg