FPSO-H Preliminary Design Approach

Author(s):  
C. Ferraz ◽  
N. G. Oliveira ◽  
J. M. Vasconcellos

Brazil Campos Basin is under large offshore oil production activity. Many new giant oil fields are under development. In many oil fields Brazil has been using ship tankers converted as FPSO platform vessel. At this moment four FPSO are in final construction phase to be installed in Campos Basin (P-43, P-48, P-50 and P-54). Many oil cargo tankers are transformed to work as FPSO. Although they are showing good characteristics, some problems are rising. The turret design approach was used in the primary FPSO’s design phase but recently the spread mooring system is also under installation in Campos Basin. Two converted FPSO’s (P-43 and P-48) were installed recently using spreading mooring system. The P-43 was installed at 800 m of water depth in Barracuda field at Campos basin. It is brother P-48 is installed at Caratinga field. Both platforms are designed to produce 300.000 barril/day. New ideas about Floating Production Storage and Offloading (FPSO) system have been in focus since some projects started working in an appropriately FPSO design direction. The Naval Architecture and Marine Engineering Department at COPPE/UFRJ has been investigating a new FPSO design and many ideas are under evaluation. One of these ideas is implement a ballast tank system to improve the floating platform behavior in waves with less structure stress. This paper presents the FPSO-H preliminary design. The aim of this project is investigate a new conception where deck are is used to separate accommodation and production plant. Also, the design applied the idea that the number of tanks should be increased to allow better weight distribution and improve the tanks inspection plain. In addition the design includes ballast tanks to increase the operator ability to control stability and vessel motion. The paper presents a case study of FPSO-H design for a Campos basin field. Graphics and tables shown the main results and recommendations are highlights for future work.

2014 ◽  
Vol 567 ◽  
pp. 197-203
Author(s):  
Anurag Yenduri ◽  
Montasir Osman Ahmed ◽  
V. John Kurian

Moored systemsof floating platforms typically have mooring lines in groups,attached to hull of the platform in different configurations.Study on therestoring behaviour of these systemsfor variousparameters of mooring lines gives an insight to decide on the preliminary design of platforms.This paper includesparametric study on the behaviour of mooring systems for various symmetric, asymmetric configurations of the lines. To compute the restoring forces of the mooring system,quasi-static analysis has been adopted and a MATLAB code named QSAML has been developed, validated with experimental tests and used for the parametric study.It has been observed that, the restoring capability of mooring system reduces whenthe lines are placed away from the wave heading.For any wave heading, the variation in restoring behaviour of mooring system with symmetric configurations is insignificant up to relatively small excursions of the platform.


Author(s):  
Jose M. Vasconcellos ◽  
Antonio C. Fernandes ◽  
Alberto Santos ◽  
Marcos D. A. S. Ferreira

Brazil Campos Basin is under large offshore oil production activity. Many new giant oil fields are under development. Brazil has been using tankers ship converted as FPSO platform vessel. At this moment three FPSO are in final construction phase to be installed in Campos Basin. Many oil cargo tankers are transformed to work as FPSO. Although they are showing good characteristics, some problems are having been emerging. The turret design approach was used in the primary FPSO’s but recently the spread mooring system with rigid risers is also under installation in Campos Basin. New ideas about Floating Production Storage and Offloading (FPSO) system have been in focus since some projects started working in an appropriately FPSO design direction. This paper spotlights one of these ideas: the FPSO tankers arrangement as a possible optimization procedure. MARPOL rule is followed but an alternative procedure is suggested to consider vessel control under wave’s action and at the same time looking for stress minimization. The aim in this procedure is increase the operator capability. The idea is allow the FPSO operator change the load condition using ballast in segregated tanks assuring a more suitable vessel condition in waves. Stability, wave response, stresses and operation ability should be also merit functions in any optimization process. A box shape FPSO-BR is used to highlight the procedure application. Results are presented and conclusion pointed out.


2021 ◽  
Vol 9 (2) ◽  
pp. 103
Author(s):  
Dongsheng Qiao ◽  
Binbin Li ◽  
Jun Yan ◽  
Yu Qin ◽  
Haizhi Liang ◽  
...  

During the long-term service condition, the mooring line of the deep-water floating platform may fail due to various reasons, such as overloading caused by an accidental condition or performance deterioration. Therefore, the safety performance under the transient responses process should be evaluated in advance, during the design phase. A series of time-domain numerical simulations for evaluating the performance changes of a Floating Production Storage and Offloading (FPSO) with different broken modes of mooring lines was carried out. The broken conditions include the single mooring line or two mooring lines failure under ipsilateral, opposite, and adjacent sides. The resulting transient and following steady-state responses of the vessel and the mooring line tensions were analyzed, and the corresponding influence mechanism was investigated. The accidental failure of a single or two mooring lines changes the watch circle of the vessel and the tension redistribution of the remaining mooring lines. The results indicated that the failure of mooring lines mainly influences the responses of sway, surge, and yaw, and the change rule is closely related to the stiffness and symmetry of the mooring system. The simulation results could give a profound understanding of the transient-effects influence process of mooring line failure, and the suggestions are given to account for the transient effects in the design of the mooring system.


1982 ◽  
Vol 104 (1) ◽  
pp. 3-8 ◽  
Author(s):  
T. Kajikawa

An ocean-based, 1-MWe (gross) test plant has been planned to establish the feasibility of OTEC (ocean thermal energy conversion) power generation in the revised Sunshine Project. The preliminary design of the proposed test plant employs a closed-cycle power system using ammonia as the working fluid on a barge-type platform with a rigid-arm-type, detachable, single-buoy mooring system. Two types each of titanium evaporators and condensers are to be included. The steel, cold-water pipe is suspended from the buoy. The design value of the ocean temperature difference is 20 K. The paper presents an overview of the preliminary design of the test plant and the tests to be conducted.


Author(s):  
G D Gosain ◽  
R Sharma ◽  
Tae-wan Kim

In the modern era of design governed by economics and efficiency, the preliminary design of a semi-submersible is critically important because in an evolutionary design environment new designs evolve from the basic preliminary designs and the basic dimensions and configurations affect almost all the parameters related to the economics and efficiency (e.g. hydrodynamic response, stability, deck load and structural steel weight of the structure, etc.). The present paper is focused on exploring an optimum design method that aims not only at optimum motion characteristics but also optimum stability, manufacturing and operational efficiency. Our proposed method determines the most preferable optimum principal dimensions of a semi-submersible that satisfies the desired requirements for motion performance and stability at the preliminary stage of design. Our proposed design approach interlinks the mathematical design model with the global optimization techniques and this paper presents the preliminary design approach, the mathematical model of optimization. Finally, a real world design example of a semi-submersible is presented to show the applicability and efficiency of the proposed design optimization model at the preliminary stage of design.


Author(s):  
Jairo Bastos de Araujo ◽  
Roge´rio Diniz Machado ◽  
Cipriano Jose de Medeiros Junior

Petrobras developed a new kind of anchoring device known as Torpedo. This is a steel pile of appropriate weight and shape that is launched in a free fall procedure to be used as fixed anchoring point by any type of floating unit. There are two Torpedoes, T-43 and T-98 weighing 43 and 98 metric tons respectively. On October 2002 T-43 was tested offshore Brazil in Campos Basin. The successful results approved and certified by Bureau Veritas, and the need for a feasible anchoring system for new Petrobras Units in deep water fields of Campos Basin led to the development of a Torpedo with High Holding Power. Petrobras FPSO P-50, a VLCC that is being converted with a spread-mooring configuration will be installed in Albacora Leste field in the second semester of 2004. Its mooring analysis showed that the required holding power for the mooring system would be very high. Drag embedment anchors option would require four big Anchor Handling Vessels for anchor tensioning operations at 1400 m water depth. For this purpose T-98 was designed and its field tests were completed in April 2003. This paper discusses T-98 design, building, tests and ABS certification for FPSO P-50.


Author(s):  
Patrick N. Koch ◽  
Janet K. Allen ◽  
Farrokh Mistree ◽  
Dimitri Mavris

Abstract To facilitate the effective solution of multidisciplinary, multiobjective complex design problems, a departure from the traditional parametric design analysis and single objective optimization approaches is necessary in the preliminary stages of design. A necessary tradeoff becomes one of efficiency vs. accuracy as approximate models are sought to allow fast analysis and effective exploration of a preliminary design space. In this paper we apply a general robust design approach for efficient and comprehensive preliminary design to a large complex system: a high speed civil transport (HSCT) aircraft. Specifically, we investigate the HSCT wing configuration design, incorporating life cycle economic uncertainties to identify economically robust solutions. The approach is built on the foundation of statistical experimentation and modeling techniques and robust design principles, and is specialized through incorporation of the compromise Decision Support Problem for multiobjective design. For large problems however, as in the HSCT example, this robust design approach developed for efficient and comprehensive design breaks down with the problem of size — combinatorial explosion in experimentation and model building with number of variables — and both efficiency and accuracy are sacrificed. Our focus in this paper is on identifying and discussing the implications and open issues associated with the problem of size for the preliminary design of large complex systems.


Author(s):  
Richard David Schachter ◽  
Carlos Gomes Jordani ◽  
Antonio Carlos Fernandes

The objective of this work is to present a design approach for the Concept and Preliminary Design Phases of Storage SPAR Buoy Platforms and to describe how the design method was developed. The influence of a VIV porosity device on the design is taken into consideration. The inherent advantages of Spar concepts for Petrobras’ applications for 1250 m, are discussed and compared with other concepts. The Spar concept was chosen. The design method development was carried out by means of a brainstorming process, using sketches and the creation of interactive flowcharts of the design processes (similar to a design spiral) comprising the main design factors, their sequencing and interrelations, for both the Concept and Preliminary Design phases. The intent of the design approach is to provide the designer with means to define quick and efficiently the optimal hull dimensions for a pre-established scenario. For the Concept Design, the method includes the definition of the main dimensions, the Wellbay, the structural topology and compartmentation, general arrangement, weight control, stability (intact, damaged and flooded), motions and mooring. A discussion on the influence of the VIV porosity device on the dimensioning and mooring of the Spar Platform is provided. A concept design application example is presented.


Author(s):  
Francisco Edward Roveri ◽  
Clo´vis de Arruda Martins ◽  
Rosianita Balena

Lazy-wave steel risers appear as a possible solution for ultra deepwater oil fields in Campos Basin. The design of such a solution, however, is a very time consuming task as several configurations must be studied, including static, dynamic and fatigue analysis. In the first cycle of design, simplified models can be used to speed up the selection process of feasible configurations. This paper presents a parametric analysis that was implemented on a computer tool, aiming to select the feasible geometric configurations for a lazy-wave steel riser in the first cycle of design.


Author(s):  
Hannah Muchnick ◽  
Janet K. Allen ◽  
David L. McDowell ◽  
Farrokh Mistree

Multilevel design is a subset of engineering design in which design problems are defined and analyzed at various levels of model complexity or resolution. Due to the potential for propagated uncertainty in a multilevel design process, design goals for maximizing system robustness to uncertainty in noise and control factors are included in the Blast resistant panels (BRP) design process. Blast resistant panels (BRPs) are sandwich structures consisting of two solid panels surrounding a honeycomb core. Under impulse loading, BRPs experience less deflection than similarly loaded solid panels of equal mass due to core crushing. In order to manage complexity in BRP concurrent product and materials design, a multilevel design approach is proposed. Additionally, in order to collect and store BRP design information in a modular and reusable format, a template-based design approach is implemented in BRP multilevel design. In this paper, a generic multilevel design template based on existing design methods (the compromise Decision Support Problem and the Inductive Design Exploration Method) is presented. The multilevel design template is then particularized and applied to BRP preliminary design, highlighting the advantages of a templatebased approach to multilevel design.


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