Buckling and Ultimate Strength Assessment of FPSO Structures

2005 ◽  
Author(s):  
Haihong Sun ◽  
Xiaozhi Wang
Keyword(s):  
Ultimate Strength ◽  
Oil And Gas ◽  
Element Analysis ◽  
Strength Criteria ◽  
Strength Assessment ◽  
Stiffened Panels ◽  
Oil And Gas Fields ◽  
Extensive Test ◽  
Offshore Oil And Gas ◽  
Classification Society

Floating production, storage and offloading systems (FPSOs) have been widely used for the development of offshore oil and gas fields because of their attractive features. They are mostly ship- shaped, either converted from existing tankers or purposely built, and the hull structural scantling design for tankers may be applicable to FPSOs. However, FPSOs have their unique characteristics. FPSOs are sited at specific locations with a dynamic loading that is quite different from those arising from unrestricted service conditions. The structures are to be assessed to satisfy the requirements of all in-service and pre-service loading conditions. The fundamental aspects in the structural assessment of FPSOs are the buckling and ultimate strength behaviors of the plate panels, stiffened panels and hull girders. The focus of this paper is to address the buckling and ultimate strength criteria for FPSO structures. Various aspects of the criteria have been widely investigated, and the results of the design formulae proposed in this paper have been compared to a very extensive test database and numerical results from nonlinear finite element analysis and other available methods. The procedures presented in this paper are based on the outcomes of a series of classification society projects in the development of buckling and ultimate strength criteria and referred to the corresponding classification society publications.

Methodologies on Hull Girder Ultimate Strength Assessment of FPSOS

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Xiaozhi Wang ◽  
Haihong Sun ◽  
Tetsuya Yao ◽  
Masahiko Fujikubo ◽  
Roger Basu
Keyword(s):  
Ultimate Strength ◽  
Structural Design ◽  
Oil And Gas ◽  
Economic Aspects ◽  
Strength Assessment ◽  
Hull Girder ◽  
Oil And Gas Fields ◽  
Offshore Oil And Gas ◽  
Gas Fields ◽  
Offshore Oil

Floating production, storage, and offloading systems (FPSOs) have been widely used for the development of offshore oil and gas fields because of their many attractive features. They are mostly ship-shaped and either converted from existing tankers or purpose-built. However, FPSOs have their own unique characteristics, including various operational requirements. In addition to that, the expectation of safety and economic aspects of FPSOs require an optimized structure to be designed. This calls for reliable structural assessment methodologies. One of the most important aspects of FPSO structural design and assessment is the hull girder ultimate strength. In this paper, different methodologies of hull girder ultimate strength assessment will be introduced and numerical calculations of hull girder ultimate strength will be presented based on six different FPSO designs. The results will then be analyzed in terms of their differences, and conclusions will be made based upon reliable methodologies for hull girder ultimate strength assessment of FPSOs.

Methodologies on Hull Girder Ultimate Strength Assessment of FPSOs

2008 ◽  
Author(s):  
Xiaozhi Wang ◽  
Haihong Sun ◽  
Tetsuya Yao ◽  
Masahiko Fujikubo ◽  
Roger Basu
Keyword(s):  
Ultimate Strength ◽  
Structural Design ◽  
Oil And Gas ◽  
Economic Aspects ◽  
Strength Assessment ◽  
Hull Girder ◽  
Oil And Gas Fields ◽  
Offshore Oil And Gas ◽  
Gas Fields ◽  
Offshore Oil

Floating production, storage and offloading systems (FPSOs) have been widely used for the development of offshore oil and gas fields because of their many attractive features. They are mostly ship-shaped, and either converted from existing tankers or purpose-built. The hull structural scantling design for tankers may be generally applicable to FPSOs. However, FPSOs have their own unique characteristics, including various operational requirements. In addition to that, the expectation of safety and economic aspects of FPSOs require an optimized structure to be designed. This calls for reliable structural assessment methodologies. One of the most important aspects of FPSO structural design and assessment is the hull girder ultimate strength. In this paper, different methodologies of hull girder ultimate strength assessment will be introduced and numerical calculations of hull girder ultimate strength will be presented based on six different FPSO designs. The results will then be analyzed in terms of their differences, and conclusions will be made based upon reliable methodologies for hull girder ultimate strength assessment of FPSOs.

Buckling and Ultimate Strength Assessments of Ship Structures

2013 ◽  
Author(s):  
Shengming Zhang
Keyword(s):  
Ultimate Strength ◽  
Fe Analysis ◽  
Development Work ◽  
Ship Structures ◽  
Element Analysis ◽  
Strength Assessment ◽  
Stiffened Panels ◽  
Development History ◽  
Bulk Carriers ◽  
Oil Tankers

This paper presents buckling and ultimate strength assessment methods for ship structures. Buckling and collapsing analysis approaches for plates, stiffened panels and hull girders are described and their development history and employments in ship design assessments are reviewed and discussed. Examples using non-linear finite (FE) element analysis are given and comparisons between results obtained by formulae and FE analysis are carried out. Lloyd’s Register’s recent research and development work on ultimate strength and its applications to existing oil tankers and bulk carriers are also presented.

Comparison Study of Various Buckling and Ultimate Strength Assessment Methodologies for Stiffened Panels in Offshore Structures

2010 ◽  
Author(s):  
Xiaozhi Wang ◽  
Haihong Sun ◽  
Xiaohong Wang ◽  
Zhinong Wang ◽  
Anil Thayamballi
Keyword(s):  
Ultimate Strength ◽  
Offshore Structures ◽  
Design Analysis ◽  
Plastic Behavior ◽  
Comparison Study ◽  
Element Analysis ◽  
Strength Assessment ◽  
Stiffened Panels ◽  
Linear Elastic ◽  
Local Strength

Strength of offshore structures including FPSOs consists broadly of three aspects which are global intact and damaged strength, and local strength. Any of these strength aspects can be assessed by either prescriptive rule or finite element analysis (FEA). While many considerations relate to behavior in the linear elastic regime, the buckling and ultimate strength of both structural components (plate and stiffened panels) and structural systems can involve material and geometric nonlinearity behavior beyond the elastic region. With the development of computers and robust methods for nonlinear FEA, there has been a tremendous increase in the number of studies of structures under plastic or elasto-plastic behavior. However, even with today’s computers and software, nonlinear FEA of offshore structures remains complex and is not routinely applied in design analysis. Considerable effort therefore continues to be devoted to the development of simplified methods for rapid structural assessment and design analysis, instead of lengthy and complex nonlinear FEA. In this paper, various bucking and ultimate strength methodologies for plate and stiffener panels are first introduced. Each method is then compared with collected test data for buckling and ultimate strength of plate panels and stiffeners. Finally, conclusions are summarized based on the comparison study.

A review of treatment technologies for produced water in offshore oil and gas fields

2021 ◽  
Vol 775 ◽  
pp. 145485
Author(s):  
Yiqian Liu ◽  
Hao Lu ◽  
Yudong Li ◽  
Hong Xu ◽  
Zhicheng Pan ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Produced Water ◽  
Oil And Gas Fields ◽  
Treatment Technologies ◽  
Offshore Oil And Gas ◽  
Gas Fields ◽  
Offshore Oil

Environmental Effect on Fatigue Life of FPSO Hull Structures

2009 ◽  
Author(s):  
Xiaozhi Wang ◽  
Booki Kim ◽  
Yanming Zhang ◽  
Ping Liao
Keyword(s):  
Oil And Gas ◽  
Low Cycle Fatigue ◽  
Oil And Gas Fields ◽  
Analysis Methodology ◽  
Work Area ◽  
Wave Conditions ◽  
Offshore Oil And Gas ◽  
Gas Fields ◽  
Offshore Oil ◽  
And Storage

Floating production, storage and offloading systems (FPSOs) have been widely used in the development of offshore oil and gas fields because of their many attractive features. These features include a large work area and storage capacity, mobility (if desired), relatively low construction cost and good stability. They are mostly ship shaped, either converted from existing tankers or purpose built. The hull structural scantling design for tankers may be applicable to FPSOs; however, FPSOs have their own unique characteristics. FPSOs are located at specific locations with a dynamic loading that is quite different from that arising from unrestricted ocean service conditions for tankers. It is also noted that the wave conditions in recent FPSO applications may be very complicated when operating in areas such as those offshore West Africa and offshore Brazil where both seas and swells exist and propagate in different directions. In this paper, the unique FPSO operational aspects, especially the load assessment due to on-site environments will be described. The methodology of handling complicated wave conditions in fatigue assessment will be addressed. Special considerations for converted FPSOs, which need to take into account their operational history as a trading tanker and low cycle fatigue due to FPSO operations, will also be introduced. Case studies will be presented and appropriate analysis methodology will be summarized. The methodology has also been adopted by ABS Guide, see ABS [1].

PHOTOGRAMMETRY MEASUREMENTS OF INITIAL IMPERFECTIONS FOR THE ULTIMATE STRENGTH ASSESSMENT OF PLATES

2021 ◽  
Vol 156 (A4) ◽  
Author(s):  
A Cubells ◽  
Y Garbatov ◽  
C Guedes Soares
Keyword(s):  
Finite Element ◽  
Ultimate Strength ◽  
Compressive Load ◽  
Initial Imperfection ◽  
Maximum Load ◽  
Surface Shape ◽  
Element Analysis ◽  
Strength Assessment ◽  
Load Carrying ◽  
Geometrical Imperfections

The objective of the present study is to develop a new approach to model the initial geometrical imperfections of ship plates by using Photogrammetry. Based on images, Photogrammetry is able to take measurements of the distortions of plates and to catch the dominant surface shape, including the deformations of the edges. Having this data, it is possible to generate faithful models of plate surface based on third order polynomial functions. Finally, the maximum load- carrying capacity of the plates is analysed by performing a nonlinear finite element analysis using a commercial finite element code. Three un-stiffened and four stiffened plates have been modelled and analysed. For each plate, two initial imperfection models have been generated one, based on photogrammetric measurements and the other, based on the trigonometric Fourier functions. Both models are subjected to the same uniaxial compressive load and boundary conditions in order to study the ultimate strength.

SUBSEA PRODUCTION FOR WELLS DRILLED FROM JACKUP DRILLING UNITS

1987 ◽  
Vol 27 (1) ◽  
pp. 357
Author(s):  
M. Thatcher ◽  
D.B. Marietta
Keyword(s):  
Oil And Gas ◽  
Production Systems ◽  
Oil And Gas Fields ◽  
Offshore Oil And Gas ◽  
The Cost ◽  
Gas Fields ◽  
Offshore Oil

Subsea production systems have been an accepted method of developing offshore oil and gas fields since the installation of the first subsea trees in the early 1960s offshore California. Generally subsea completions have been done from floating drilling vessels on wells with subsea wellhead equipment. A number of wells have been completed subsea by bottom supported jackup rigs on wells drilled using mudline suspension equipment. The subsea completion equipment and methods utilised to adapt mudline suspension wells for a subsea production tree are described. This method of completion offers important benefits as it allows completion of wildcat or delineation wells, it can be used in areas of small, scattered reservoirs, and it can be used in conjunction with floating production systems. The cost associated with these subsea completions is roughly equivalent to those of standard subsea completions from floating vessels. An overview of a typical completion system is presented and compared.

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