Method and apparatus for connecting a riser pipe to blow out preventer stack at the head of an oil well

In a device for connecting a riser pipe to the B.O.P Stack of a well head,

• said B.O.P. Stack carrying a connecting spigot at its upper end and at least one service tube positioned eccentrically with respect to the axis of the B.O.P. Stack,
• while said riser pipe carries a sealing member at its lower end, telemetrically controlled apparatus for latching the sealing member in sealing position, a downwardly open approach guide, and at least one service tube positioned to register with the service tube on said stack when said stack and pipe are in both axial alignment with each other and occupy a predetermined angular position with respect to each other,
• the improvement according to which said riser pipe carries at least one member having a downwardly oriented bearing surface and said B.O.P. Stack has a component with an upwardly oriented bearing surface, said bearing surfaces being positioned to bear against each other when said riser pipe and B.O.P. Stack have been guided into axial alignment by said approach guide,
• said riser pipe carries fluid pressure means positioned to act between said pipe and said at least one member having a downwardly oriented bearing surface and adapted to lower said sealing member into contact with said spigot after said upwardly and downwardly oriented surfaces have come into contact with each other, and said riser pipe has been rotated on said bearing surfaces to bring said service tubes into registration with each other,
• in which the fluid pressure cylinders are attached at one end to the periphery of the tip and at the other end to a sleeve slidable along said tip and attached to the approach guide, said slidable sleeve being immobilized against rotation by at least one finger sliding in a longitudinal groove in the external surface of the tip,
• and in which the annular bearing surface on the B.O.P Stack is on said connecting spigot.

In a device for connecting a riser pipe to the B.O.P. Stack of a well head,

• said B.O.P. Stack carrying a connecting spigot at its upper end and at least one service tube positioned eccentrically with respect to the axis of the B.O.P. Stack,
• while said riser pipe carries a sealing member at its lower end, telemetrically controlled apparatus for latching the sealing member in sealing position, a downwardly open approach guide, and at least one service tube positioned to register with the service tube on said stack when said stack and pipe are in both axial alignment with each other and occupy a predetermined angular position with respect to each other,
• the improvement according to which said riser pipe carries at least one downwardly oriented member and said B.O.P. Stack has a component with an upwardly oriented member, said members being positioned to bear against each other when said riser pipe and B.O.P. Stack have been guided into axial alignment by said approach guide,
• a low friction bearing on one of said members, and
• said riser pipe carries fluid pressure means positioned to act between said pipe and said at least one downwardly oriented member and adapted to lower said sealing member into contact with said spigot after said upwardly and downwardly oriented members have come into contact with each other, and said riser pipe has been rotated on said low friction bearing to bring said service tubes into registration with each other.