Fractal column offset tension leg platform (COTLP)

Abstract

A Fractal Column Offset Tension Leg Platform (COTLP) consists of a semi-submersible hull type, tension moored to the seabed. The Fractal COTLP advances the state of technology by utilizing fractal arrangements of repeated, similar structural units, consisting of continuous pontoons and intermittent columns, to provide better construction, operation, stability, payload and service life advantages over existing Tension Leg Platform (TLP) types. Varying, fractal-like geometric arrangements also provide for sizing and configuration advantages and the capability to work in greater water depths than existing TLP technology. Furthermore, fractal arrangements and inter-column spacing can also be optimized to minimize platform hydrodynamic response to waves, thereby reducing mooring and hydrodynamic loads and consequently achieving an optimal and safer platform structure with a longer fatigue life.

1 . A tension leg platform structure for an offshore platform in which at least three buoyant, structurally continuous pontoons and structurally intermittent support columns are arranged in a fractal manner about a vertical, central axis to arrive at a semi-submersible, tendon moored floating platform. 
     
     
         2 . The substructure of  claim 1  such that buoyant pontoons are continuous structural members. 
     
     
         3 . The substructure of  claim 1  such that the connections between buoyant columns and pontoons is such that only one column is structurally integral to one pontoon. 
     
     
         4 . The substructure of  claim 1  that the connections of the tendons to the pontoons does not result in a radial mooring arrangement and platform symmetry, but rather a spiral mooring geometry and spiral platform symmetry. 
     
     
         5 . The substructure of  claim 3  such that the columns rest upon or are connected on top of the pontoons. 
     
     
         6 . The substructure of  claims 2  and  3  allow for more optimal structural design and construction technology/methodology. 
     
     
         7 . The substructure of  claims 1  and  4  that the spiral arrangement allows for more than three (3) columns to be supported, in increments of one (1): that is, three (3) columns, four (4) columns, five (5) columns, and so forth. 
     
     
         8 . The substructure of  claims 1  and  6  that the spiral arrangement allows for greater dispersion of the mooring foundations on the sea floor, which in turn provide mooring performance advantages. 
     
     
         9 . The substructure of  claims 1  and  6  that the spiral mooring arrangement allows for of one (1), two (2), three (3), and so forth, as many tendons per pontoon as required.