BLOWOUT PREVENTER Russian patent published in 1998 - IPC

FIELD: oil production and drilling equipment. SUBSTANCE: preventer has body with lower and upper flanges, inserts which hermetically seal pipe and located in movable rams with mechanism for control of their movement. Installed in through-hole of preventer are removable units of permanent centering of pipes or hermetic sealing of cable (depending on kind of operations performed). Included in first unit is replaceable centralizer which is made up of two half-rings fixed by clamp. Inner diameter of centralizer is larger than outer diameter of pipe joint which is hermetically sealed by preventer. Second unit is made up of coaxially located upper ring, lower ring and cylindrical sealing member positioned between them. Each of aforesaid component is made up of two half-rings which are splittable in diametrical plane and connected together by studs. Studs are rigidly connected with upper and lower half-rings, and in upper part they are provided with nuts. Additional removable sealing member is made in the form of cylinder with radial slit and of inner diameter equal to diameter of cable being hermetically sealed. Upper ring is made up of two half-rings connected by hinge with mounting handles for convenient mounting. Preventer ensures safety in performing perforation operations and cuts operating cost due to introduction of removable units for permanent centralizing of pipes and hermetic sealing of cable. EFFECT: high efficiency. 1 cl, 3 dwg