TORPEDO PILES AND SUCTION PILES: GEOTECHNICAL ANALYSIS AND INSTALLATION EXPERIENCES IN SEEK FOR OPTIMAL ANCHORING SYSTEM IN DEEPWATER CLAY SOILS

Torpedo piles have emerged as a compelling alternative to conventional suction piles for anchoring floating facilities in deepwater developments. Gaining momentum in the offshore industry over the last decade, their design has been enhanced through specialised laboratory tests and the application of analytical and numerical tools. However, compared to suction piles, there is limited field data on torpedo piles, as their primary use has been in offshore Brazil. This study is the first step of a series of analysis on torpedo piles aiming at further developing design and installation. Various aspects of the torpedo pile solution need to be thoroughly studied, should this concept prove pivotal in competing with conventional suction piles in offshore frontier acreage. Elements such as anchor dimensions and thus holding capacity, fabrication, transportation and installation costs need to be evaluated in search of the most optimal solution. Leveraging recent installation feedback from Subsea7 on torpedo piles T-120 and existing literature, this paper presents an interdisciplinary assessment and comparison of suction and torpedo piles. It also includes an analysis of the novel finned pile design, currently applied in an ongoing Subsea7 project in Brazil. The paper comprises finite element analysis (FEA) to compare holding capacities and offers insights into installation, transportation and fabrication costs of both anchoring systems.