SUBSURFACE SAFETY VALVE Russian patent published in 1997 - IPC

FIELD: oil-producing industry, in particular, devices for operation of oil and gas wells used in tight shutoff of wellbore in well repairs and in emergency situation of failure of wellhead equipment. SUBSTANCE: safety valve consists of body. shutoff unit, shutoff unit control mechanism. Distinguishing feature of the offered safety valve consists in that body of check valves and shutoff unit form hollow accommodating control mechanism cylinder hydraulically connected with above-valve space. Located on the cylinder is emergency automatic system for closing of safety valve. Emergency automatic system is adjusted for permissible capacity of the given well. Emergency system is one-time use and includes high-pressure vessel, shutoff unit of high-pressure vessel and shutoff unit drive. Operation of emergency system results in closing of safety valve, then safety valve may operate as usual. EFFECT: higher efficiency. 1 dwg