Patent ID: 8544404

Claim:
A mono-column floating production, storage and offloading (FPSO) structure of symmetrical polygonal or cylindrical form in relation to a vertical central axis, with an upper portion standing above sea level and a lower portion that is submerged below sea level when in use for offshore petroleum exploitation, the upper portion and the lower portion being joined in a transition zone that is inclined downwards and outwards with respect to the vertical central axis, and terminating in a bilge keel with a flat bottom at a lower end of the lower portion, wherein the FPSO structure comprises a hull ( 11 ) of circular or polygonal horizontal cross-section, including at least one load tank ( 12 ) having the vertical central axis passing therethrough, and surrounded in a radial direction outboard by permanent ballast tanks ( 13 ) and moonpools ( 14 ), wherein the permanent ballast tanks and the moonpools are positioned alternately with each other, and disposed symmetrically around the vertical central axis.