Patent ID: 8256993
Filing Date: 2012-09-04
Classification: E21B,F16L

Abstract:
1. A riser tower structure comprising a plurality of elongate conduits arranged around a central core, and being provided with buoyancy and/or insulation blocks along at least part of its length, the buoyancy and/or insulation blocks being formed out of a plurality of main sections, which are attached together around the central core, to form a channel therefor and provide the riser tower structure with a substantially circular cross-sectional profile, wherein the main sections further comprise recesses around their periphery and along their length for the location of the elongate conduits, said blocks further comprising closing pieces for each recess to retain said elongate conduits when in place and thereby providing the riser tower structure with a substantially unbroken cylindrical cross section, and wherein one or more strakes are provided on the outside of said blocks.