Motion Response Analysis of FPSO’s CALM Buoy Offloading System

2015 ◽  
Author(s):  
Liping Sun ◽  
Xu Zhang ◽  
Youwei Kang ◽  
Shuhong Chai
Keyword(s):  
Oil And Gas ◽  
Numerical Models ◽  
Response Analysis ◽  
Floating Bodies ◽  
Mooring Lines ◽  
Motion Response ◽  
Operation Conditions ◽  
Practical Engineering ◽  
Offshore Oil And Gas ◽  
Motion Characteristics

Catenary anchor legs mooring (CALM) buoy offloading system is widely used in offshore oil and gas exploitation engineering. Proper prediction of the motion response of CALM systems is very important to the fatigue analysis of offloading pipelines and the design of mooring lines. Numerical models of a CALM system in survival and operation conditions will be established in this paper, and motion characteristics of the buoy and its sensibility to environmental factors, as well as performance of slender bodies are derived. More importantly, the shuttle tanker’s stability in plane and the risk of its collision with other floating bodies are focused on in this paper. All of the conclusions will provide recommendation for designing in practical engineering.

Physical Component Testing to Simulate Dynamic Marine Load Conditions

2013 ◽  
Author(s):  
Philipp R. Thies ◽  
Lars Johanning ◽  
Tessa Gordelier ◽  
Andrew Vickers ◽  
Sam Weller
Keyword(s):  
Oil And Gas ◽  
Fatigue Tests ◽  
Test Rig ◽  
Mooring Lines ◽  
Energy Devices ◽  
Component Testing ◽  
Component Test ◽  
Operational Load ◽  
Offshore Oil And Gas ◽  
Load Conditions

The reliability and integrity of components used in the marine offshore environment is paramount for the safety and viability of offshore installations. The engineering challenge is to design components that are robust enough to meet reliability targets whilst lean enough to minimise cost. This is particularly the case for offshore marine renewable installations which operate in the same, possibly harsher, environment as offshore oil and gas installations, and are subjected to highly cyclic and dynamic wave, wind and operational load conditions. The cost of electricity produced has to compete with other means of electricity generation and does thus not offer the same profit margins available as oil and gas commodities. As a result, components for marine renewable installations have to meet the target reliability, without the application of costly safety factors to account for load and environmental uncertainties. Industries with similar design tasks such as the aviation or automotive industry have successfully used a service simulation test approach to develop robust yet lean designs. This paper builds on an approach to establish and validate the reliability of floating renewable energy devices in which dedicated component testing using the purpose built Dynamic Marine Component test rig (DMaC) plays a pivotal role to assess, validate and predict the reliability of components in the marine environment. This paper presents a test rig for both static and fatigue tests of marine components such as mooring lines and mooring shackles under simulated or measured load conditions and provides two case studies from recently conducted mooring component tests. This includes an investigation into the load behaviour of synthetic mooring ropes and the ageing of mooring shackles.

A Fundamental Study on Motion Characteristics and Cargo Handling Efficiency of the Large-Scale Floating Coal Transshipment Station

2018 ◽  
Author(s):  
Hiroaki Eto ◽  
Yoh Shikita ◽  
Tomoki Ikoma ◽  
Koichi Masuda ◽  
Hiroaki Kihara
Keyword(s):  
Large Scale ◽  
Mutual Interference ◽  
Response Analysis ◽  
Bulk Carrier ◽  
Motion Response ◽  
Cargo Handling ◽  
Wave Drift ◽  
Bulk Carriers ◽  
Drift Force ◽  
Motion Characteristics

This paper describes the motion characteristics and cargo handling efficiency of the Large-Scale Floating Coal Transshipment Station (LFTS). Indonesia is a main country supplying coal in the Asia-Pacific region, it is important to ensure a stable coal supply to Japan. Because the topography of the seabed near East Kalimantan Island, Indonesia’s main coal production area, is shallow, it is difficult for bulk carriers to reach the coast. Therefore, LFTS is proposed, which will be used as a relay base between coal-barging barges from land and bulk carriers offshore. By installing LFTS, improvement of coal transport efficiency is expected. In considering feasibility of the LFTS system, it is important to know the cargo handling operation rate in the target area, LFTS can load 500,000 tons of coal and the draft will fluctuate greatly depending on the loading condition of coal. Therefore, when the draft is shallow, the freeboard becomes large and resonates with long-term component of the wind load and when the draft is deep, the wave force and fluid force including the slowly varying wave drift force affect the fluctuation. Also, LFTS and bulk carrier are large-scale structures, the fluid forces acting on both affect each other, so the influence of hydrodynamic mutual interference between two floating bodies cannot be ignored. In this study, fluid analysis in consideration of the hydrodynamic mutual interference of LFTS system is conducted. And, response analysis of LFTS and a bulk carrier in irregular wave which considered compound external forces such as wave load and slow varying wave drift force, wind load, tidal current was performed. As a result, it was confirmed that the motion response of LFTS was not upset because LFTS was large. Therefore, without considering the motion response of the LFTS, the cargo handling efficiency is calculated from the response analysis results of the bulk carrier and the oceanic condition of the setting sea area. As a result, the cargo handling efficiency is satisfied in the state where bulk carrier is installed leeward of LFTS, and it was confirmed that the LFTS system could be operated satisfactorily if the installation was appropriate.

Development of Dual-Lifting Technique for Installation of Topside Mega-Modules

2016 ◽  
Author(s):  
Dong Woo Jung ◽  
Hyun Joe Kim ◽  
Hae Sung Ji ◽  
Hyoen Su Jeong ◽  
Mihee Nam ◽  
...  
Keyword(s):  
Production Efficiency ◽  
Oil And Gas ◽  
Ocean Basin ◽  
Structural Safety ◽  
Integration Time ◽  
Project Schedule ◽  
Construction Time ◽  
Mooring Lines ◽  
Central Process ◽  
Operation Conditions

As many deep-sea oil and gas fields are being developed, floating platforms becomes larger with more complicated topsides. However, the construction time is demanded to be shorter to meet the overall project schedule. The use of very large topside modules is one of the effective ways to reduce the integration time and decrease the possibility of fabrication defects. The Ichthys Project’s CPF (Central Process Facility) is currently being constructed at Samsung Heavy Industries (SHI). The CPF will be the world’s largest production semi-submersible platform. The hull is constructed on the Offshore Floating Dock and most of the topside modules are prepared at workshops and integrated by floating cranes on the hull. To maximize production efficiency in terms of reduced integration time and reworks, several topside modules are assembled into a larger module weighing up to 7,400 tonne spanning 150m long. Such large module cannot be handled by a single 8,000 tonne F/C, the largest crane that SHI owns. This fact initiated the idea of dual-lifting with a combination of the two F/Cs (8,000 tonne and 3,600 tonne) which enables lifting, transportation and integration of the mega-modules properly and safely without building a larger capacity F/C. Using different sized F/Cs increases the flexibility of the operation of the F/Cs. To ensure safety during the dual-lifting, the two F/Cs are synchronized to be controlled as a single crane unit. During hoisting, all the measured data such as loads and positions of the hooks, and rotation of the module, are monitored in real time basis and used to hoist the module automatically. All the systems are designed to be redundant. Additional engineering works are performed to check the safety such as 1) structural analysis to investigate the structural safety with out-of-phased motions at boom-tip 2) time-domain analysis and 3) model test in ocean basin with the operation scenarios in real environments to obtain the dynamic load factors and the guidance on the operation limits in terms of wave heights. The two crane barges are moored side-by-side using fenders and mooring lines, and tug operation conditions are planned not only to move but also to push the two barges from sideways to be moored tightly, which minimizes the possibility of relative motions between the two barges. The developed system had been applied to the integration of all the modules successfully weighing from 4600 to 7400 tonne. It is expected to be applied to many other offshore projects to keep the construction schedule on time. This paper will address and share the technical experiences obtained during the dual lifting of the mega-modules for the Ichthys Project’s CPF.

Rationale of Riser System Selection for an FPSO Application

2007 ◽  
Author(s):  
Liping Sun ◽  
Xiongliang Yao ◽  
Zhenghong Hu
Keyword(s):  
Oil And Gas ◽  
Reservoir Properties ◽  
Technical Feasibility ◽  
Field Development ◽  
Deepwater Riser ◽  
To Come ◽  
Offshore Oil And Gas ◽  
Motion Characteristics ◽  
Deepwater Risers ◽  
System Selection

Floating Production, Storage and Offloading (FPSO) system has been used widely in the offshore oil and gas industries worldwide. In recent years, FPSO concept has been deployed in deep and ultra-deepwater field development including West of Africa, Offshore Brazil, and Offshore China. Meanwhile, more and more deepwater risers have been deployed from concept to offshore installation. Compared to other type deepwater floaters (e.g. Spar, TLP, Semisubmersible), the severe motion characteristics of an FPSO makes the riser concept selection and design much more challenges. Other constraints imposed by field reservoir properties (e.g. high temperature\high pressure), disconnection requirements for early production FPSO system, and significant increase in water depth even exclude some riser concepts. This paper presents detailed evaluation of potential deepwater riser concepts applicable for an FPSO. Among the deepwater concepts, steel catenary risers (SCR), flexible risers, hybrid risers have been successfully deployed to FPSO application. In addition, there are also other viable riser concepts for FPSO application including lazy wave SCR, Tension Leg Riser (TLR), Hybrid ‘S’ Riser System (HySR), Hybrid Catenary Riser (HCR), and more to come. The evaluation of deepwater riser concepts for FPSO application is conducted in terms of technical feasibility, design constraints, track records, fabrication, offshore construction, and cost with focus on the existing and field proven riser concepts. Technical challenges and technology gaps are highlighted. The technical feasibility of some of the riser concepts for certain FPSO application has been demonstrated through analysis and calculation. Novel ideas have been generated for particular requirements. Particular attention is paid to the discussion with the application to offshore China. This paper shows the steel riser and hybrid riser are the most viable ones for deep and ultra-deepwater FPSO. Flexible riser and hybrid riser are the preferred solution for FPSO in China.

NOVEL PRODUCTION CONCEPTS FOR DEEP WATER AND ASSOCIATED HYDRODYNAMIC PROBLEMS

1998 ◽  
Vol 38 (1) ◽  
pp. 855
Author(s):  
K.P. Thiagarajan
Keyword(s):  
Deep Water ◽  
Oil And Gas ◽  
Production Systems ◽  
Gas Production ◽  
Oil And Gas Production ◽  
Cylindrical Structures ◽  
Campos Basin ◽  
Offshore Oil And Gas ◽  
Motion Characteristics ◽  
Offshore Oil

Offshore oil and gas production is now reaching to great depths, in excess of 1000 m, in the Gulf of Mexico and the Campos Basin, offshore Brazil. It will not be long before Australian companies look towards probable reserves in deeper waters that still remain within the Australian exclusive economic zone. Production concepts for deep and ultra deep water thus need to be studied and researched, and a constant watch should be maintained on developments around the world in this area.This paper presents two popular, and constantly evolving, concepts for deep water, namely: tension leg platforms (TLP) and spars. Tension leg platforms have been in existence for about 14 years, and are actively sought for deep water by worldwide operating companies. They are vertically moored by means of taut tethers which present interesting motion characteristics and unique hydrodynamic problems. Spar platforms are currently being installed for production purposes. These are large deep draft cylindrical structures moored by catenary or taut spread mooring systems. Physical details, advantages and limitations of both systems are discussed.While many aspects of these production systems are now understood, there are still several unknowns. Deeper waters translate to newer problems. Potential problems of the future are discussed in this paper, and research needs are highlighted.

ANCHORING OF STRUCTURES IN DEEP WATER

1982 ◽  
Vol 22 (1) ◽  
pp. 112 ◽  
Author(s):  
Einar Tore Moe ◽  
Odd A. Olsen
Keyword(s):  
Deep Water ◽  
Oil And Gas ◽  
Wind Waves ◽  
Gas Production ◽  
Mooring Lines ◽  
Oil And Gas Production ◽  
Oil And Gas Exploration ◽  
Anchoring System ◽  
Offshore Oil And Gas ◽  
Global And Local

The oil and gas exploration industry continually discovers energy resources at greater water depths, and in many of the structures now being designed for offshore oil and gas production the anchoring system is one of the key components, having significant influence on operational characteristics as well as safety.The best possible understanding of the problems involved in anchoring is therefore essential, and an evaluation of a design for deep-water long-term anchoring should include:evaluation of possible excitation sources at actual site (wind, waves, current)dynamic analysis of the structure and mooring linesevaluation of soil properties and anchor behaviourevaluation of fatigue strength of mooring linesevaluation of conditions for corrosion and corrosion protection.In this paper 'the state of the art' within these problem areas is discussed. Sample calculations of global and local dynamics of the mooring lines are compared with results from conventional quasistatic analysis to demonstrate the importance of taking into account dynamic phenomena and oscillations caused by wind, waves and current action. Areas for further research are also discussed.

scholarly journals A Comprehensive Study on the Serbuoys Offshore Wind Tension Leg Platform Coupling Dynamic Response under Typical Operational Conditions

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2067
Author(s):  
Zhe Ma ◽  
Nianxin Ren ◽  
Yin Wang ◽  
Shaoxiong Wang ◽  
Wei Shi ◽  
...  
Keyword(s):  
Modal Analysis ◽  
Coupling Effect ◽  
Suppressive Effect ◽  
Wave Period ◽  
Offshore Wind ◽  
Tension Leg Platform ◽  
Mooring Lines ◽  
Motion Response ◽  
Operational Conditions ◽  
Motion Characteristics

A new type of offshore wind tension leg platform (TLP) connected with a series of buoys (Serbuoys-TLP) is proposed. With the consideration of coupling effect, derivations on the stiffness of the Serbuoys-TLP mooring lines are given. The complicated coupling motion characteristics of the TLP with buoys system are investigated by means of experiments and numerical analysis. The suppressive efficiency on the surge under some condition is nearly 68%, when the wave period is the common wave period of the East China Sea (6 s). Namely, the suppressive effect of series buoys on surge motion response of TLP is analyzed. Through several aspects of suppressive effect on the surge including wave properties, submerge volume and position of buoys are investigated. The modal analysis method is also adopted to interpret the coupled motion response. In the end, the responses of TLP and Serbuoys-TLP are simulated under actual sea conditions with the consideration of wind, wave and current. Based on the parametric study using the modal analysis combined with hydrodynamic analysis, the conclusion can be drawn that the surge of TLP can be effectively suppressed by the addition of a series of buoys in the Serbuoys-TLP.

scholarly journals Kicking the OPEC Habit

2000 ◽  
Vol 122 (05) ◽  
pp. 44-51
Author(s):  
Michael Valenti
Keyword(s):  
Oil And Gas ◽  
Oil Prices ◽  
Floating Platform ◽  
Mooring Lines ◽  
Sea Bed ◽  
Floating System ◽  
Heating Oil ◽  
Offshore Oil And Gas ◽  
Offshore Oil ◽  
And Storage

This article highlights that major offshore oil and gas projects may help North America reduce its dependence on the oil cartel. When members of the Organization of Petroleum Exporting Countries (OPEC) cut their production by 4 million barrels per day from March 1999 to March 2000, they tripled oil prices, from $11 to $33 per barrel. The combination of higher gasoline, diesel, and heating oil prices led President Clinton and Congress to pressure the OPEC countries to increase their production. Spar technology has been used for 25 years for loading buoys and storage vessels. The spar is a floating system, basically a cylinder on end that maintains its position with mooring lines sunk into the seabed. Many offshore oilfields are beyond the reach of underwater pipelines. This is an opportunity seized by SOFEC Inc. in Houston. Since 1972, the company, a subsidiary of the FMC Corp., has designed equipment to support floating production storage and offloading systems. These systems consist of a floating platform, basically a moored ship-shaped vessel, equipped to accept oil and gas from a drilling system on the sea bed.

SCR Fatigue Feasibility Prediction for Deepwater FPSO Applications

2012 ◽  
Author(s):  
Sherry Xiang ◽  
Peimin Cao
Keyword(s):  
Oil And Gas ◽  
Early Stage ◽  
Design Flow ◽  
Response Analysis ◽  
Field Development ◽  
Steel Catenary Risers ◽  
Fluid Transfer ◽  
Offshore Oil And Gas ◽  
System Selection ◽  
Prediction Approach

Many of the recent offshore oil and gas discoveries in the world have occurred in deep waters, at locations far away from the existing subsea infrastructure. Floating Production Storage and Offloading systems (FPSOs) are the preferred field development solutions for those locations with mild and moderate environments. The simplest fluid transfer system between the seabed and the FPSO is a simple catenary configuration, with Steel Catenary Risers (SCRs) as the preferred solution for deep water, high pressure and high temperature applications. This paper introduces an effective engineering SCR fatigue screening methodology for FPSO applications. The focus of this study is to better understand SCR fatigue performance at Touch Down Point (TDP) and develop a simple but reasonable correlation between FPSO porch motion and the riser dynamic stress response at TDP. This methodology enables one to perform the porch motion statistics analysis and the riser dynamic response analysis independently. By using the wave screening approach, SCR fatigue feasible map can be effectively developed. The paper presents an example performing the fatigue screening evaluation. SCR feasibility design flow chart for FPSO application is also addressed. Particular for FPSO application in a new development, the fatigue feasibility prediction approach along with the strength feasibility check can help the project make the informative decision on the overall FPSO and riser system selection at the early stage of the development.

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