Parameter Optimization Method for FPSO Docking Mooring Lines Under Typhoon Conditions Based on Improved Genetic Algorithms

doi:10.16183/j.cnki.jsjtu.2024.295

Abstract

Abstract:

Floating production storage and offloading (FPSO) units are critical equipment in offshore oil development. When mooring at a dock in harsh environmental conditions such as typhoons, their large main dimensions and simultaneous exposure to combined wind, wave, and current forces impose high demands on the load-bearing capacity of the mooring system. Additionally, the mooring lines are arranged in a complex manner, with nearly 60 lines, making it almost infeasible to use a comparative method to find the optimal parameter combination for all mooring lines due to the extensive computational workload. Therefore, this paper comprehensively considers multi-directional wind, wave, and current loads and develops an iterative optimization method for FPSO typhoon-resistant mooring line system parameters based on an improved genetic algorithm. The method takes line lengths as variable parameters, with different combinations of line lengths regarded as individuals in the genetic iteration. By checking the line load of each combination under typical conditions, the fitness of each combination is evaluated for iterative optimization, ultimately yielding an optimized mooring line system. The comparison of mooring schemes before and after optimization reveals that the optimized mooring line length parameters show a trend to tighten longer lines and relax shorter lines, thereby improving the utilization of lines that previously had lower loads. The optimized mooring scheme reduces the maximum mooring line load under all conditions by 12.2% without significantly affecting FPSO motion amplitudes. By merely adjusting the tension of the mooring lines, the optimized scheme meets safety standard checks without altering other parameters. This optimization method can enhance the safety of mooring systems within the constraints of limited dock resources and provide a reference for docking mooring operations.

Key words: docking mooring, mooring lines force, genetic algorithm, parameter optimization, time domain method

CLC Number:

P751

CHEN Xinhao, JIANG Jijiang, XU Yuwang, FU Shixiao, LIU Chenglong, SONG Bin. Parameter Optimization Method for FPSO Docking Mooring Lines Under Typhoon Conditions Based on Improved Genetic Algorithms[J]. Journal of Shanghai Jiao Tong University, 2026, 60(6): 985-995.

Figures/Tables 18

Fig.1

Fig.2

Fig.3

Fig.4

Tab.1

Fig.5

Fig.6

Tab.2

Tab.3

Tab.4

Fig.7

Fig.8

Fig.9

Fig.10

Fig.11

Fig.12

Fig.13

Tab.5

References 20

[1]	高明俊. 张力腿平台码头系泊水动力性能研究及系泊形式分析[D]. 天津: 天津大学, 2020.
	GAO Mingjun. Research on mooring performance and analysis of mooring forms of tension leg platform wharf[D]. Tianjin: Tianjin University, 2020.
[2]	赵笑辉. 基于AQWA的大型矿砂船舶码头系泊特性及稳泊安全研究[D]. 厦门: 集美大学, 2022.
	ZHAO Xiaohui. AQWA-based mooring characteristics of Very Large Ore Carrier and stable berthing safety study[D]. Xiamen: Jimei University, 2022.
[3]	CHERNJAWSKI M. Mooring of surface vessels to piers[J]. Marine Technology and SNAME News, 1980, 17(1): 1-7. doi: 10.5957/mt1.1980.17.1.1 URL
[4]	NATARAJAN R, GANAPATHY C. Analysis of moorings of a berthed ship[J]. Marine Structures, 1995, 8(5): 481-499. doi: 10.1016/0951-8339(95)97305-R URL
[5]	邹志利, 张日向, 张宁川, 等. 风浪流作用下系泊船系缆力和碰撞力的数值模拟[J]. 中国海洋平台, 2002, 17(2): 22-27.
	ZOU Zhili, ZHANG Rixiang, ZHANG Ningchuan, et al. The numerical simulation of mooring force & impact force of ship moored to offshore platform[J]. China Offshore Platform, 2002, 17(2): 22-27.
[6]	刘俊红, 赵魏, 崔秀达. 30万t FPSO船体码头抗台系泊设计[J]. 船海工程, 2021, 50(2): 37-40.
	LIU Junhong, ZHAO Wei, CUI Xiuda. Anti-typhoon quay mooring of 300 000 t FPSO hull[J]. Ship & Ocean Engineering, 2021, 50(2): 37-40.
[7]	BOLSHEV A, FROLOV S, SHONINA E. Optimization of mooring systems for an anchored floating structure in survival and normal-operation modes[J]. Power Technology and Engineering, 2024, 57(5): 710-715. doi: 10.1007/s10749-024-01723-z
[8]	PILLAI A C, THIES P R, JOHANNING L. Mooring system design optimization using a surrogate assisted multi-objective genetic algorithm[J]. Engineering Optimization, 2018, 51(8): 1370-1392. doi: 10.1080/0305215X.2018.1519559 URL
[9]	郭强. 基于遗传算法的系泊优化分析与应用[D]. 哈尔滨: 哈尔滨工程大学, 2016.
	GUO Qiang. Optimization analysis and application of mooring system based on genetic algorithm[D]. Harbin: Harbin Engineering University, 2016.
[10]	BOLSHEV A, FROLOV S, SHONINA E. Mooring system optimization for marine floating hydrotechnical structures[J]. Magazine of Civil Engineering, 2022, 111(3): 11112.
[11]	ALI M O A, YENDURI A, et al. Optimization of mooring line design parameters using Mooring Optimization Tool for FPSO (MooOpT4FPSO) with the consideration of integrated design methodology[J]. Ocean Engineering, 2022, 264: 112499. doi: 10.1016/j.oceaneng.2022.112499 URL
[12]	YU Y, ZHAO M, LI Z, et al. Optimal design of asymmetrically arranged moorings in a floating production system based on improved particle swarm optimization and RBF surrogate model[J]. Marine Structures, 2024, 94: 103576. doi: 10.1016/j.marstruc.2024.103576 URL
[13]	LAZZERINI G, COIRO D, TROISE G. Optimization of a floating offshore wind turbine platform and mooring lines according to an innovative wind farm wake control technique[J]. The Institution of Engineering and Technology, 2023, 7: 365-375.
[14]	MA G, DU Z, WANG H, et al. Design and analysis of grid mooring system for gravity net cage with a comprehensive optimization method[J]. Ocean Engineering, 2024, 309: 118524. doi: 10.1016/j.oceaneng.2024.118524 URL
[15]	杨昆. 风浪流耦合作用下的系泊船舶与码头动力学分析[D]. 哈尔滨: 哈尔滨工程大学, 2023.
	YANG Kun. Dynamics analysis of mooring ship and wharf under wind wave and current coupling[D]. Harbin: Harbin Engineering University, 2023.
[16]	许峰. 自升式钻井平台码头抗台风系泊工程研究[D]. 上海: 上海交通大学, 2016.
	XU Feng. A research of on-quay anti-typhoon mooring engineering for a jack-up drilling platform[D]. Shanghai: Shanghai Jiao Tong University, 2016.
[17]	中国船级社. 海上移动平台入级规范[S]. 北京: 人民交通出版社股份有限公司, 2023.
	China Classification Society. Rules for classification of mobile offshore units[S]. Beijing: China Communications Press Co., Ltd., 2023.
[18]	OCIMF. Mooring equipment guidelines[M]. 4th ed. London, UK: OCIMF, 2018: 7-10.
[19]	张鼎, 何夏茵. FSRU码头系泊系统特性影响因素分析[J]. 船舶工程, 2022, 44(Sup.1): 609-612.
	ZHANG Ding, HE Xiayin. Analysis of factors affecting the characteristics of FSRU docking mooring system[J]. Ship Engineering, 2022, 44(Sup.1): 609-612.
[20]	ZHANG D, LIU S, CHEN Y, et al. Influence of different mooring factors on characteristics of docking mooring system for large container vessel[C]// Proceedings of the International Offshore and Polar Engineering Conference. Ottawa, Canada: ISOPE, 2023: 3634-3639.

序号	类型	产品名称	直径/ mm	干重/ (kg·m^-1)	结构	破断载荷/kN
1	主缆	超高分子量聚乙烯缆绳	58	1.885	12股	2 058
2	尾缆	尼龙66缆绳	120	9.3	12股	2 058

参数	设计值
吃水/m	7.549
排水量/t	141 696
垂线间长/m	345.3
垂向重心位置(距基线)/m	24.049
纵向重心位置(距艉垂线)/m	155.04

方向	角度/(°)	有义波高/m	谱峰周期/s
W	0	1.13	3.92
WSW	22.5	1.27	4.28
SW	45	0.83	3.51
SSW	67.5	1.01	3.85
S	90	1.23	4.27
SSE	112.5	1.66	4.72
SE	135	1.90	8.12
ESE	157.5	2.31	8.95
E	180	2.33	8.23
ENW	202.5	0.10	8.23
NE	225	0.10	8.23
NNE	247.5	0.10	8.23
N	270	0.10	8.23
NNW	292.5	0.10	4.72
NW	315	0.10	8.12
WNW	337.5	0.10	8.95

环境参数	取值
水深/m	9.1~16.24
波浪谱	JONSWAP谱
流速/(m·s^-1)	2.24
风速/(m·s^-1)	36.9

自由度	优化前幅值	优化后幅值	幅值变化
纵荡/m	1.273	1.231	-0.042
横荡/m	0.572	0.580	0.008
垂荡/m	0.359	0.360	0.001
横摇/(°)	0.961	1.021	0.060
纵摇/(°)	0.093	0.094	0.001
艏摇/(°)	0.268	0.275	0.007