Experimental study on the hydrodynamic behaviour of an FPSO in a deepwater region of the Gulf of Mexico

• Published in: Ocean engineering Vol. 129; pp. 549 - 566
• Main Authors: Lopez, Jaime Torres, Tao, Longbin, Xiao, Longfei, Hu, Zhiqiang
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2017
• Subjects: Deep-water; FPSO; Hydrodynamics; Mooring lines; Non-collinear; Deep-water; Hydrodynamics; Non-collinear; Mooring lines; FPSO
• ISSN: 0029-8018; 1873-5258
• DOI: 10.1016/j.oceaneng.2016.10.036

As offshore oil and gas exploration moves progressively toward greater water depths, it becomes more challenging to predict the environmental forces and global responses of floating production storage and offloading (FPSO) systems and the dynamic behaviour of the mooring lines and risers. The validation of complex numerical models through scale model experimental testing is restricted by the physical limits of the test facilities. It is not feasible to install the equivalent full length mooring lines and riser systems and select an appropriate scale model for reducing the uncertainties in the experimental test programme for deepwater and ultra-deepwater conditions. The combination of an appropriate scale FPSO model with a suitable level of equivalent effect reduced depth using a hybrid passive truncated experimental methodology for the mooring lines and risers is a practical approach. Following recent discoveries, FPSO has been proposed for a portion of the planned development in the southern Gulf of Mexico (GOM) in water depth ranging from 1000 to 2000m. Based on a scale model and a hybrid passive truncated experimental method for mooring lines and risers, this paper investigates the global response of an FPSO, as well as the dynamics of mooring lines and risers in the context of prevailing environmental conditions for field development in a specific deepwater location in GOM. The experiments revealed that the main horizontal motion response of the FPSO (surge) under non-collinear loading condition is almost two-times that of the collinear loading condition. The mooring lines in the non-collinear condition are more sensitive to the dynamic response and risers appear to have an important influence on the low frequency damping. •Experiments are conducted in a DW offshore basin to study the coupled dynamics of a FPSO with mooring and riser systems.•It is revealed that the surge motion response of the FPSO is significantly higher under non-collinear environment.•Influence of risers on the extreme motion response of the FPSO system is examined.•Viscous damping contribution of the FPSO model and the truncated mooring lines and riser systems are obtained.•Experimental data obtained in this study can be used as benchmark for future numerical and experimental study.