Marine riser system

A marine riser system for transferring fluid between a plurality of mutually separated locations on the seabed and a vessel floating on the surface of the sea, the riser system comprising:

• (a) a submerged buoy,
• (b) a like plurality of risers each suspended from the buoy and extending from the buoy in mutually different directions to a respective one of the locations on the sea bed whereby differently acting directions of riser-weight-applied pull on the buoy tend to keep the buoy horizontally between the locations, the vessel floating substantially above the submerged buoy,
• (c) a like plurality of flexible conduits extending from the vessel to the submerged buoy,
• (d) a respective connector carried by the submerged buoy and connecting the lower end of the respective flexible conduit to the upper end of one of the risers;
• and
• (e) wherein the vessel in use is stationed above the buoy such that the buoy is substantially directly below the center of yaw of the vessel.

A marine riser system for transferring fluid between a plurality of mutually separated locations on the seabed and a vessel floating on the surface of the sea, the riser system comprising:

• (a) a submerged buoy,
• (b) a like plurality of risers each suspended from the buoy and extending from the buoy in mutually different directions to a respective one of the locations on the sea bed whereby differently acting directions of riser-weight-applied pull on the buoy tend to keep the buoy horizontally between the locations, the vessel floating substantially above the submerged buoy,
• (c) a like plurality of flexible conduits extending from the vessel to the submerged buoy,
• (d) a respective connector carried by the submerged buoy and connecting the lower end of the respective flexible conduit to the upper end of one of the risers;
• and
• (e) wherein the submerged buoy is tethered substantially vertically to an anchor in the sea bed.

A marine riser system for transferring fluid between a plurality of mutually separated locations on the seabed and a vessel floating on the surface of the sea, the riser system comprising:

• (a) a submerged buoy,
• (b) a like plurality of risers each suspended from the buoy and extending from the buoy in mutually different directions to a respective one of the locations on the sea bed whereby differently acting directions of riser-weight-applied pull on the buoy tend to keep the buoy horizontally between the locations, the vessel floating substantially above the submerged buoy,
• (c) a like plurality of flexible conduits extending from the vessel to the submerged buoy,
• (d) a respective connector carried by the submerged buoy and connecting the lower end of the respective flexible conduit to the upper end of one of the risers;
• and
• (e) wherein the buoy is fitted with roll motion damping means.

A marine riser system for transferring fluid between a plurality of mutually separated locations on the seabed and a vessel floating on the surface of the sea, the riser system comprising:

• (a) a submerged buoy,
• (b) a like plurality of risers each suspended from the buoy and extending from the buoy in mutually different directions to a respective one of the locations on the sea bed whereby differently acting directions of riser-weight-applied pull on the buoy tend to keep the buoy horizontally between the locations, the vessel floating substantially above the submerged buoy,
• (c) a like plurality of flexible conduits extending from the vessel to the submerged buoy,
• (d) a respective connector carried by the submerged buoy and connecting the lower end of the respective flexible conduit to the upper end of one of the risers;
• and
• (e) wherein at least one riser comprises steel pipe disposed in a catenary.

A marine riser system for transferring fluid between a plurality of mutually separated locations on the seabed and a vessel floating on the surface of the sea, the riser system comprising:

• (a) a submerged buoy,
• (b) a like plurality of risers each suspended from the buoy and extending from the buoy in mutually different directions to a respective one of the locations on the sea bed whereby differently acting directions of riser-weight-applied pull on the buoy tend to keep the buoy horizontally between the locations, the vessel floating substantially above the submerged buoy,
• (c) a like plurality of flexible conduits extending from the vessel to the submerged buoy,
• (d) a respective connector carried by the submerged buoy and connecting the lower end of the respective flexible conduit to the upper end of one of the risers;
• and
• (e) wherein the end of at least one riser adjacent the sea bed is disposed in a wave formation.

A marine riser system for transferring fluid between a plurality of mutually separated locations on the seabed and a vessel floating on the surface of the sea, the riser system comprising:

• (a) a submerged buoy,
• (b) a like plurality of risers each suspended from the buoy and extending from the buoy in mutually different directions to a respective one of the locations on the sea bed whereby differently acting directions of riser-weight-applied pull on the buoy tend to keep the buoy horizontally between the locations, the vessel floating substantially above the submerged buoy,
• (c) a like plurality of flexible conduits extending from the vessel to the submerged buoy,
• (d) a respective connector carried by the submerged buoy and connecting the lower end of the respective flexible conduit to the upper end of one of the risers;
• and
• (e) wherein the plurality of flexible conduits extending from the vessel each to a respective connector are collectively disposed in an array resembling a “Chinese lantern”).