Wave slamming load test and structural analysis on deep water FPSO hull

Author of the article:XU Tiantian1, ZHANG Meirong2

Author's Workplace：1. CNOOC China Ltd., Tianjin Branch, Tianjin, 300459, China; 2. China Offshore Oil Engineering Company, Tianjin, 300451, China

Key Words：Floating production storage and offloading; Sea keeping performance; Wave slamming; Model test; Hull strength

Abstract：A deep water floating production storage and offloading (FPSO) hull is designed as super fat, simple angular lines shape. It is necessary to check the FPSO hull structural strength against wave slamming. The environmental conditions and load cases for FPSO ocean towing design is determined based on Germanischer Lloyd Noble Denton GL0030/ND Guidelines for Marine Transportations and environmental condition of the towing route. The sea keeping performance tank model test is carried out to study wave slamming load at FPSO bow and stern under on-site operation extreme environmental conditions and ocean towing survival condition, focusing on the analysis of wave slamming load characteristics and load distribution for different peak period of wave spectrum and wave direction under ocean towing, so that the design requirements for FPSO hull wave slamming that exceed Bureau Veritas Classification Society NR445 Rules for the calssification of offshore units & NR467 Rules for the classification of steel ship are determined. The main results reveal that no green water on FPSO main deck at the stern is found, which verifies the feasibility of the design of lines shape at the stern. FPSO bow and stern structure is specially strengthened, and hull strength is analyzed by PATRAN/NASTRAN software, which meets Bureau Veritas Classification Society rules requirements. This paper can be used as a reference for the hull structure design of deep water FPSO.