Patent ID: 8251005

Claim:
A spar platform comprising: a deck; a buoyant tank assembly, comprising: a first buoyant section connected to the deck, the first buoyant section comprises an aspect ratio from 0.001 to 1, the first buoyant section aspect ratio defined as a vertical draft of the first buoyant section divided by a diameter of the first buoyant section; a second buoyant section disposed beneath the first buoyant section, the second buoyant section comprises an aspect ratio from 0.001 to 2, the second buoyant section aspect ratio defined as a vertical height of the second buoyant section divided by a diameter of the second buoyant section; and a rigid buoyant or non-buoyant section spacing structure connecting the first and second buoyant sections in manner providing a horizontally extending vertical gap there between, the gap comprises an aspect ratio from 0.15 to 2, the gap aspect ratio defined as a vertical height of the gap divided by a diameter of the first buoyant section; a counterweight; and a counterweight spacing structure connecting the counterweight to the buoyant tank assembly, the buoyant tank assembly further comprising: a third buoyant or non-buoyant section disposed beneath the first and second buoyant sections, the third buoyant section comprises an aspect ratio from 0.001 to 2, the third buoyant section aspect ratio defined as a vertical height of the third buoyant section divided by a diameter of the third buoyant section; and a second rigid buoyant or non-buoyant section spacing structure connecting the second and third sections in a manner providing a second horizontally extending vertical gap there between, the second gap comprises an aspect ratio from 0.15 to 2, the gap aspect ratio defined as a vertical height of the gap divided by a diameter of the second buoyant section.