Advanced concept design and numerical study of suction bucket foundation in deep ocean

The commonly used bucket foundation for the tension leg platforms (TLPs) depends on pumping to generate negative pressure. The capacity of pump limits application of the bucket foundations to water depth around 350 m. To make TLPs applicable in deepwater field, an advanced design named integrated suction foundation for TLPs is proposed in this paper. The most important improvement is the design of a pressure-resistant storage module, which utilizes the high hydrostatic pressure in deep ocean to drive water into the module to generate negative pressure for suction, not to utilize pump to drive water. Another breakthrough in the design is that all buckets are connected using trusses to form an integrated foundation. Due to the integrity it is feasible for the bucket foundations penetrating together into soil so the installation time and cost can be reduced significantly. Finite element analysis (FEA) was performed for the integrated suction foundation with environmental data based on South China Sea. The analysis results show that the integrated suction foundation is applicable well to water depth of 1000 m. In all, the newly designed integrated suction foundation will be of a great benefit to the applications of TLPs in deep ocean.

► Advanced concept design is proposed for bucket foundations applied in deep ocean.
► Pressure-resistant storage module with two valves inside buckets is designed.
► Bucket foundations are connected together using truss structures.
► FEA results indicate applicability of the advanced design in water depth of 1000 m.