Optimization of Mooring Systems for Floating Offshore Platforms Considering Seabed Obstacles

2017 ◽  
Author(s):  
Bruno da Fonseca Monteiro ◽  
Carl Horst Albrecht ◽  
Beatriz Souza L. Pires de Lima ◽  
Breno Pinheiro Jacob
Keyword(s):  
Production Systems ◽  
Element Model ◽  
Optimization Methods ◽  
Offshore Platforms ◽  
Mooring Lines ◽  
Oil Reserves ◽  
Offshore Production ◽  
Deep Waters ◽  
Candidate Solution

With the constant increase of known oil reserves in deep and ultra-deep waters, floating production systems (FPS) have been established as the main option for offshore production activities. This work presents recent advances regarding an innovative application of evolutionary optimization methods to the design of mooring systems for FPS. Here the focus in in the consideration of actual scenarios with seabed obstacles and other restricted areas where anchors cannot be positioned. The optimization tool employs the Particle Swarm Optimization (PSO) method. The constraints are treated by specialized constraint-handling techniques, and each candidate solution is evaluated through nonlinear analyses coupling the hydrodynamic model of the platform hull with a Finite Element model of the mooring lines and risers. A case study illustrates the application of the optimization for a real-world scenario.

Optimal Design Methodology for Multi-Component Mooring Systems in Deep Water

2010 ◽  
Author(s):  
Long Yu ◽  
Jiahua Tan
Keyword(s):  
Optimal Design ◽  
Deep Water ◽  
Design Methodology ◽  
Element Model ◽  
Gas Production ◽  
Mooring Line ◽  
Mooring System ◽  
Offshore Platforms ◽  
Mooring Lines ◽  
Restoring Force

Multi-component mooring systems, one of the crucial equipments of offshore platforms, play an important role in deep water oil&gas production because of relative low cost and light weight. A single mooring line can be constructed by combination of wire ropes, chains, fiber ropes, buoys and connectors etc. and provide adequate restoring force at fairlead point of platforms. Although the static and dynamic analyzing approaches for a determined multi-component system have been studied already, it is still hard to design and predetermine an appropriate mooring system that can satisfy the codes with multi-component lines. Referred to the conventional mooring system design method, this paper brings out an optimal design methodology for multi-component mooring systems. According to quasi-static method, at extreme offset position of the platform, an optimization model for designing the multi-component mooring line with biggest tension in deep water has been provided. Then, with the aid of design wave method and morison equation, a finite element model has been used to calculate mooring line dynamics at each fairlead point in time domain. The nonlinear interaction of mooring lines and seabed has also been investigated. Heave and surge of the platform have also been considered. Both 2D and 3D mooring system models have been built to search the interference of the lines and directional influence of environment loads like current and wave. The paper applied this set of analyzing methods and processes into a deep water semisubmersible serving at South China Sea. Compared with the results calculated by other software, the methodology mentioned in the paper got similar result with less weight and bigger restoring force.

HSE Consequences of FPSO Mooring Lines Pretension Uncertainty in Deep Waters Applications

2020 ◽  
Author(s):  
Jairo B. Araújo ◽  
Joel S. Sales ◽  
Antonio C. Fernandes ◽  
Ana C. S. Thurler
Keyword(s):  
Mooring Lines ◽  
Indirect Measurements ◽  
Extreme Loads ◽  
Deep Waters ◽  
Integrity Management ◽  
Precision System ◽  
Anchor Points ◽  
Design Requirements ◽  
Safety And Environment

Abstract The purpose of FPSO (Floating Production Storage and Offloading) mooring system is to keep the unit operating in site in order to attend the Health, Safety and Environment (HSE) requirements and to meet the production risers design requirements. The pretension specification is a design task and it is a key activity due to its influence on extreme loads and fatigue life for both the mooring lines and risers. It is surprising that the project pretension specifications are not always actually implemented in practice and followed during all the unit life. Some inaccurate methods are used to get the actual pretension and may cause significant errors, and this may cause pretensions values outside design allowable tolerances. A contemporary uncertainty analysis method that uses numerical simulations to estimate the consequences and propagation of the uncertainties in pretensions is applied. A case study is presented for the case of an operating FPSO moored by a spread system, offshore Brazil. A second investigation compares the uncertainty of pretensions measured by means of sensors with the uncertainties that arise from indirect measurements by top angles and as built data for mooring segments and anchor points. The paper finally shows the need of a Mooring Integrity Management (MIM) implementation of at least annual pretension measurements with a robust and higher precision system.

Metocean Design Criteria for Deep Water Offshore Systems

2015 ◽  
Author(s):  
Michele Drago ◽  
Matteo Mattioli ◽  
Federico Quondamatteo
Keyword(s):  
Multivariate Analysis ◽  
Water Column ◽  
Production Systems ◽  
Wind Waves ◽  
Practical Case ◽  
Current Profile ◽  
Design Data ◽  
Deep Waters ◽  
Surface Development

In the last decades the off-shore hydrocarbon extraction industry has extended its field of activities in very deep waters up to more than 2000 m. Extraction and production systems can vary between complete subsea development with export pipelines to on-shore treatment plants and surface development by means of surface units (SSFU) connected to subsea wells by risers and anchored by mooring systems which extend through the whole water column. For exclusively subsea developments, including sealines, the metocean design data and criteria to be developed and the applicable methodologies to derive them are well established. Univariate theory is usually applied in order to quantify the risk of failure due to (extreme) sea conditions. The surface developments and the connections through the water column (e.g. risers, moorings) are newly challenging aspects. They could suffer from severe damages due to the occurrence of critical combinations of different variables during a single sea storm:: thus, it may be important to consider the joint occurrence of different forcing conditions (i.e. multivariate analysis). The present manuscript provides a simplified methodology in order to carry out a sensible multivariate analysis of the contemporary data such as wind, waves and current. Three different cases are analyzed: i) the correlation of extremes of different variables (wind, wave and current), ii) the extreme profiles of current and iii) the current profile climate. A practical case study is illustrated throughout the paper.

scholarly journals Swarm-Inspired Algorithms to Optimize a Nonlinear Gaussian Adaptive PID Controller

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3385
Author(s):  
Erickson Puchta ◽  
Priscilla Bassetto ◽  
Lucas Biuk ◽  
Marco Itaborahy Filho ◽  
Attilio Converti ◽  
...  
Keyword(s):  
Pid Controller ◽  
Optimization Algorithms ◽  
Optimization Methods ◽  
Buck Converter ◽  
Algebraic Solution ◽  
Nonlinear Load ◽  
Bee Colony ◽  
Arduous Task ◽  
Whale Optimization

This work deals with metaheuristic optimization algorithms to derive the best parameters for the Gaussian Adaptive PID controller. This controller represents a multimodal problem, where several distinct solutions can achieve similar best performances, and metaheuristics optimization algorithms can behave differently during the optimization process. Finding the correct proportionality between the parameters is an arduous task that often does not have an algebraic solution. The Gaussian functions of each control action have three parameters, resulting in a total of nine parameters to be defined. In this work, we investigate three bio-inspired optimization methods dealing with this problem: Particle Swarm Optimization (PSO), the Artificial Bee Colony (ABC) algorithm, and the Whale Optimization Algorithm (WOA). The computational results considering the Buck converter with a resistive and a nonlinear load as a case study demonstrated that the methods were capable of solving the task. The results are presented and compared, and PSO achieved the best results.

scholarly journals MODEL-BASED DESIGN OF AM COMPONENTS TO ENABLE DECENTRALIZED DIGITAL MANUFACTURING SYSTEMS

2021 ◽  
Vol 1 ◽  
pp. 2127-2136
Author(s):  
Olivia Borgue ◽  
John Stavridis ◽  
Tomas Vannucci ◽  
Panagiotis Stavropoulos ◽  
Harry Bikas ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Systems ◽  
Production Systems ◽  
Data Generation ◽  
Production Networks ◽  
Model Based ◽  
Manufacturing Technologies ◽  
Am Processes ◽  
Final Consumer

AbstractAdditive manufacturing (AM) is a versatile technology that could add flexibility in manufacturing processes, whether implemented alone or along other technologies. This technology enables on-demand production and decentralized production networks, as production facilities can be located around the world to manufacture products closer to the final consumer (decentralized manufacturing). However, the wide adoption of additive manufacturing technologies is hindered by the lack of experience on its implementation, the lack of repeatability among different manufacturers and a lack of integrated production systems. The later, hinders the traceability and quality assurance of printed components and limits the understanding and data generation of the AM processes and parameters. In this article, a design strategy is proposed to integrate the different phases of the development process into a model-based design platform for decentralized manufacturing. This platform is aimed at facilitating data traceability and product repeatability among different AM machines. The strategy is illustrated with a case study where a car steering knuckle is manufactured in three different facilities in Sweden and Italy.

RURAL WOMEN AND ENTREPRENEURSHIP: A CASE STUDY IN HERAKLION CRETE PREFECTURE, GREECE

2011 ◽  
Vol 16 (02) ◽  
pp. 269-284 ◽  
Author(s):  
AIKATERINI LASSITHIOTAKI
Keyword(s):  
Rural Women ◽  
Production Systems ◽  
Traditional Food ◽  
Enterprise Risk ◽  
Enterprise Model ◽  
Control Production ◽  
Modern Business ◽  
Domestic Roles ◽  
Entrepreneurial Beliefs

This article investigates the entrepreneurial beliefs/attitudes, ambitions, expectations, goals and visions of rural women who choose to cooperate and found Women's Rural cooperatives in the Prefecture of Heraklion on the island of Crete. The results of a qualitative study involving a sample of eight chairwomen of rural women's established Traditional Food Production cooperatives indicated that the traditional domestic roles (housewife, mother), the low level of education, the lack of professional skills, enterprise experience and mostly the unwillingness of rural women to undertake enterprise risk, have turned them toward an enterprise model that lacks modern business methods in the use of quality control production systems, in the production of Protected Geographical Identification Goods and/or Certified Local Traditional Food and/or Organic Products, in the use of new organizing and managing technologies, in advertising and promoting products and in administrative renewal.

Urban Vehicle Emissions Management under Uncertainty - A Traffic Planning Model with Interval-Parameter Programming

2013 ◽  
Vol 864-867 ◽  
pp. 1586-1591
Author(s):  
Hong Liang Zhang
Keyword(s):  
Vehicle Emissions ◽  
Optimization Methods ◽  
Transportation System ◽  
Programming Method ◽  
Planning Model ◽  
Traffic Planning ◽  
Interval Parameter ◽  
Interval Linear ◽  
Virtual City

In this study, an interval-parameter programming method has been used for urban vehicle emissions management under uncertainty. The model improves upon the existing optimization methods with advantages in uncertainty reflection, system costs and limitation of emission. Moreover, the model is applied to a case study of urban vehicle emissions management in a virtual city. The results indicate that the interval linear traffic planning model can effectively reduce the vehicles emission and provide strategies for authorities to deal with problems of transportation system.

Integrity Assessment of Damaged Flexible Pipe Cross-Sections

2014 ◽  
Author(s):  
Guomin Ji ◽  
Bernt J. Leira ◽  
Svein Sævik ◽  
Frank Klæbo ◽  
Gunnar Axelsson ◽  
...  
Keyword(s):  
Cross Sections ◽  
Three Dimensional ◽  
Element Model ◽  
Computer Code ◽  
Flexible Pipe ◽  
Dynamic Stresses ◽  
Integrity Assessment ◽  
Residual Capacity ◽  
Nonlinear Finite Element Model

This paper presents results from a case study performed to evaluate the residual capacity of a 6″ flexible pipe when exposed to corrosion damages in the tensile armour. A three-dimensional nonlinear finite element model was developed using the computer code MARC to evaluate the increase in mean and dynamic stresses for a given number of damaged inner tensile armor wires. The study also includes the effect of these damages with respect to the associated stresses in the pressure spiral. Furthermore, the implications of a sequence of wire failures with respect to the accumulated time until cross-section failure in a probabilistic sense are addressed.

Blockage Remediation in Deep Water Pipelines

2002 ◽  
Author(s):  
Ca´ssio Kuchpil ◽  
Marcelo A. L. Gonc¸alves ◽  
Antoˆnio C. P. Ferreira ◽  
Roberto S. Albernaz ◽  
Cla´udio S. Camerini ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Production Systems ◽  
Operational Conditions ◽  
Deep Waters ◽  
Water Pipelines ◽  
Pros And Cons ◽  
High Production ◽  
Organic Deposit ◽  
Production Losses ◽  
Exothermal Chemical

Flow assurance is an important issue in the design and operation of production systems in deep waters. The implementation of prevention and remediation methods is necessary mainly due to the low temperatures, high production pressures, long tie-ins and oils prone to organic deposit formation. Despite the development and improvement of these prevention and remediation techniques, failures or exceptional operational conditions can lead to the complete blockage of the submarine flowlines, risers or equipment. Although the complete blockage is not frequent, the related production losses generally are high; furthermore, the technical difficulties and the costs involved in the removal of blockages can be high. The steps to the remediation of subsea blockages are the localization, identification and removal methods. Due to the variety of problems, the different subsea layouts and surface facilities, it is not possible to have a general recipe for all problems. This paper presents some blockage remediation cases, including the localization and blockage remediation methods. The blockage localization methods used for the blockage removal cases described in this paper are the following: a) the echo of pressure pulses reflected at the blockage and b) a tool that detects the pipeline diameter variation with the pipeline pressure variations. The field results for these methods and the pros and cons of the methods are discussed. The remediation methods described are the following: external heating, internal intervention and exothermal chemical reaction using gravity.

Optimal Design of Spatial Grid Structure Using Group Search Optimization

2011 ◽  
Vol 243-249 ◽  
pp. 6044-6048 ◽  
Author(s):  
Bing Yuan ◽  
Feng Ming Ren ◽  
Gen Quan Zhong ◽  
Jing Zhou
Keyword(s):  
Optimization Design ◽  
Element Model ◽  
Optimization Methods ◽  
Grid Structure ◽  
Optimization Analysis ◽  
Search Optimization ◽  
Spatial Grid ◽  
The One ◽  
Group Search ◽  
Design Proposal

An economic and safety design proposal of the spatial grid structure is very difficult to find according to traditional design method.The group search optimization and its improved algorithm are applied in optimization design of a spatial grid structure in this paper. In this paper the finite element model of the spatial grid structure is firstly built through the platform of ANSYS. Then based on the parameterized programme language ADPL of ANSYS ,the group search optimization (GSO) and the quick group search optimization(QGSO ) are compiled ,the optimization analysis of the spatial grid structure are carried out. Finally, the optimization results and the optimization one from ANSYS are compared. It show that the optimization methods hereinbefore are feasible and the design proposals of them are better than the one of ANSYS.

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