Parametric Trends of Arctic Gravity Based Structures Available to Purchase

Gravity Based Structures (GBS) have been used as hydrocarbon exploration or production structures in arctic regions to a water depth of about 30m and sub-arctic regions up to about 100m. The weight of the construction materials for the GBS and hence its cost depends on a large number of engineering parameters and constraints. For a particular location, the site-specific values would be used in the design. However, guidance can be obtained by performing a parametric analysis of GBS’s over a wide range of engineering requirements that may be required in future structures. We present the results of a parametric investigation into the minimum size of production GBS in ice-covered regions for the 50 to 150m water depth range and 0 to 4 million barrel product storage range. The trends in the size, cost and material construction weight of the GBS are described. In addition, aspects such as the solid ballast requirements and the floating draft of the structures are discussed. The applicability of the various designs is discussed with reference to the Chukchi, Beaufort and West Greenland Seas.