초록 ▼

A marine riser system is provided which extends between a floating offshore platform and well means in a seabed formation and which has riser end portions connected in novel manner to the floating platform and to wellhead structure at the well hole. Each end portion of the riser is adapted to yield

A marine riser system is provided which extends between a floating offshore platform and well means in a seabed formation and which has riser end portions connected in novel manner to the floating platform and to wellhead structure at the well hole. Each end portion of the riser is adapted to yield axially, laterally, and rotatively during movement of the riser relative to the platform and to the wellhead structure. Each end portion of the riser is provided with fulcrum or pivot contacts with hawse pipe carried by the platform and with hawse pipe or casing means provided in the wellhead structure. Bending stresses at the riser end portions are reduced at the platform and at the wellhead structure.

대표청구항 ▼

In a marine riser system for conducting fluid between a platform and a well means in a seabed formation and for minimizing stresses in said riser system, the combination of: a riser pipe having an upper riser portion and a lower riser portion; a hawse pipe fixed on said platform and extending from a

In a marine riser system for conducting fluid between a platform and a well means in a seabed formation and for minimizing stresses in said riser system, the combination of: a riser pipe having an upper riser portion and a lower riser portion; a hawse pipe fixed on said platform and extending from a production deck to a submerged platform member and receiving said upper riser portion; a hawse pipe at said well means extending into said seabed formation for a selected distance and receiving said lower riser portion; and means non-fixedly connecting said upper and lower riser portions to their respective hawse pipes including fulcrum members on each of said upper and lower riser portions, the fulcrum members on each riser portion being separated a selected distance to permit bending of the pipe portion between said separated fulcrum members and being loosely fitted within said hawse pipes for axial, lateral, and rotational relative movement with respect thereto.