Patent ID: 7934462

Claim:
A semi-submersible floating platform for use in offshore applications, comprising: a semi-submersible hull structure including support columns, a pontoon structure adjoined to said support columns at a lower end thereof, and a deck structure supported at an upper end of said columns for supporting said deck and equipment mounted thereon above the water surface; and passive damper weight means disposed below said hull for providing hydrodynamic mass, damping, and in-water weight, said damper weight means including at least one generally rectangular ring-shaped damper weight member having box-shaped sides of generally rectangular transverse cross section surrounding a central opening; a plurality of flexible connection members connected at upper ends to said hull structure and at lower ends to said at least one damper weight member for suspending said at least one damper weight member at a distance beneath said hull structure to provide hydrodynamic mass, damping, and in-water weight to said platform during operation, and said flexible connection members being maintained in tension by said at least one damper weight member during operation; and riser guide means disposed in said at least one damper weight member central opening for receiving and guiding through said damper weight member a portion of at least one riser attached at a lower end to a wellhead on the seabed and supported at an upper end by said deck structure for connection with hydrocarbon production equipment on said deck structure.