Flexible/rigid riser system
AssigneeContinental Emsco Company
InventorsCharles J. Moses, Rajko M. Simic
Life of this patent
Estimating the term…
Abstract
A continuous bend flexible/rigid riser system is provided for coupling a subsea location to an offshore platform or vessel. The riser system comprises a first rigid pipe section coupled at its upper end to the platform. A plurality of intermediate pipe sections are mutually coupled end to end, and are coupled in series with the first rigid pipe section by means of a plurality of flexible couplings. The lower end of the last in the series of intermediate pipe sections is coupled to the subsea location. The flexible/rigid riser system reduces bending stresses transmitted along the riser by allowing angular displacement of the pipe sections with respect to one another.
Claims20
A riser for coupling an offshore platform to a subsea location on a seabed, said riser comprising:
- a first rigid riser section having a first end portion and a second end portion, said first end portion being coupled to said offshore platform;
- a last rigid riser section having a first end portion and a second end portion, said second end portion of said last rigid riser section being coupled to said subsea location;
- at least one intermediate rigid riser section;
- a first flexible elastomeric coupling joining the first rigid riser section to the at least one intermediate rigid riser section;
- a second flexible elastomeric coupling joining the at least one intermediate rigid riser section to the last rigid riser section;
- and
- wherein each of the flexible elastomeric couplings permits the adjacent rigid riser sections to be displaced angularly with respect to one another with a predetermined stiffness, so that said riser can be deployed in a catenary configuration.
A flexible/rigid riser system for coupling an offshore platform to a plurality of subsea locations on a seabed, said system comprising:
- a plurality of risers, each of said risers comprising:
- a first rigid riser section having a first end portion and a second end portion, said first end portion being coupled to said offshore platform;
- a last rigid riser section having a first end portion and a second end portion, said second end portion of said last rigid riser section being coupled to said respective subsea location;
- at least one intermediate rigid riser section;
- a first flexible elastomeric coupling joining the first rigid riser section to the at least one intermediate rigid riser section;
- a second flexible elastomeric coupling joining the at least one intermediate rigid riser section to the last rigid riser section;
- and
- wherein each of the flexible elastomeric couplings permits the adjacent rigid riser sections to be displaced angularly with respect to one another with a predetermined stiffness, so that said riser can be deployed in a catenary configuration.
A riser for coupling an offshore platform to a subsea location on a seabed, said riser comprising:
- a first rigid riser section having a first end portion and a second end portion, said first end portion being coupled to said offshore platform;
- a last rigid riser section having a first end portion and a second end portion, said second end portion of said last rigid riser section being coupled to said subsea location;
- at least one intermediate rigid riser section;
- a first flexible elastomeric coupling joining the first rigid riser section to the at least one intermediate rigid riser section;
- a second flexible elastomeric coupling joining the at least one intermediate rigid riser section to the last rigid riser section;
- and
- wherein each of the flexible elastomeric couplings comprises a body having a hollow inner portion and upper and lower flanges extending radially into said inner portion, upper and lower annular interface members disposed on said body within said hollow inner portion against said upper and lower flanges respectively, and upper and lower annular spherical elastomeric bearings disposed adjacent the upper and lower annular interface members respectively and abut opposite ends of respective adjacent rigid riser sections.
Dependencies are inferred from the claim text.