ABSTRACT
Gravity platforms have been used during the past in the harsh/ice-infested Arctic ocean environmental contexts for drilling/production/storage of offshore oil; recently, they have also been used for generating energy from strong offshore winds. A variety of configurations have been in use, as shown in Figure 9.1a through g [1-4], ranging from the North Sea gravity platforms (shown in Figure 9.1a through e), offshore wind farms (shown in Figure 9.1f), to the Arctic gravity structures (shown in Figure 9.1g). These structures have proved to be competitive alternatives to the commonly used steel jacket structures due to their large deck capacity, rapid construction/installation times, and the availability of stronger soils (in comparison with the soft Gulf of Mexico soils). In spite of these obvious advantages for gravity base structures (GBS), it must be remembered that both concrete gravity base and steel jacket structures have been used side by side in the northern North Sea as shown in Figure 9.2 [5]. The preference for a certain structure is based on the abundance and connectedness of oil in the field, preference of the owner, and the economy involved in the development of the field. While the North Sea gravity structures have been installed in water depths ranging from 70.0 to 320.0 m, the Arctic gravity structures have been installed in much shallower water depths ranging from 9.0 to 18.0 m [6].
