Mooring Characteristics Of The FLNG System

With the economic development and improvement of the industrial level, the demandfor energy has been increased dramatically, especially in the petrochemical resources.Onshore oil and gas resources have been depleted, therefore oil exploration graduallyshifted to near the coast, and even the deep-sea region, marginal small oil and gas fieldswill gradually be developed. FLNG will be widely used as one of effective miningprocessing equipments. The mooring security of the FLNG transporter unloading processis systematically studied in this paper, including the side by side mooring between theLNG-FPSO and LNG, and the LNG carrier moored to a wharf.Based on three-dimensional potential flow theory, FLNG system is calculated andanalyzed by using the multi-body hydrodynamic software-AQWA. Firstly, according tothe offsets table of LNG-the FPSO and LNG carriers, finite element models of the bothsides are created, and hydrodynamics characteristics of the multi-body is investigated inthe frequency domain, the hydrodynamic parameters of the two hull have been obtainedsuch as the RAO, and the influence of hydrodynamic interactions, transverse hull spacingparameters etc. on the hydrodynamic response. And then, suitable mooring lines andfenders models are selected, and added it to the finite element models, and quasi-staticanalysis of the FLNG mooring system is done in time domain with the relevant marineenvironmental load, time-varying curves of fenders pressure and mooring lines tension areobtained by the calculation. Finally, according to the provisions of the relevant norms,calculations of the LNG carrier moored to wharf are done, and the impact ofenvironmental factors on the moored LNG carrier is discussed, such as wave, wind etc.With the analysis of this paper, we understand the characteristics and key issues ofhydrodynamic response in multi-floating-body, and make a numerical prediction ofmooring characteristics of the side-by-side mooring system, and then provide a referencefor design, application and development of the FLNG mooring system.