Methodology for the Structural Analysis of Compliant Towers at Ultimate and Serviceability Limit States

The short service life of oil fields and limited oil deposits in shallow waters requires a constant search for new oil fields in deeper waters. Compliant towers are one of the most suitable structures for water depths between 300 m and 600 m, where fixed structures are economically unfeasible. The principal characteristics of compliant towers include a minimal number of cross sections in their main structural elements throughout their height, combined with significant flexibility and buoyancy. Due to their flexibility and buoyancy, gravitational loads at the deck do not significantly impact the foundation. Moreover, compliant towers do not need advanced building systems, installation processes or special maintenance. Additionally, the large height of compliant towers reduces their natural frequencies, which prevents them from being within the frequency range of environmental forces capable of producing structural resonance. For this reason, efforts are made to design compliant towers to be as flexible as possible. Hence, this research is focused on examining a methodology for the structural analysis of compliant towers at ultimate and serviceability limit states for a water depth of 550 m in the Mexican waters of the Gulf of Mexico.