WELL FLOW BREAKER Russian patent published in 1997 - IPC

FIELD: operation of underground storages of gaseous and liquid hydrocarbons; applicable in prevention of blowouts of stored products into atmosphere in cases of seal failure of wellhead. SUBSTANCE: the offered flow breaker has body with immovable piston. Sealing member with hole and seat is installed between well string and body. Movable gate installed for overlapping the hole in sealing member and forming airtight working chamber connected with surface control system. Novelty consists in that body is made in form of concentric cylindrical bushings forming the control chamber communicated with working chamber, surface control system and additional working chamber. The latter is formed between body and movable bushing with seat located inside body. Bushing is installed for motion along body axis. Located in body lower part, in airtight hollow between movable bushing and string adapter, is spring-loaded disk valve installed for interaction with movable bushing seat. Body upper and lower parts have annular recesses for return springs. EFFECT: higher efficiency. 2 cl, 2 dwg