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1.
As one of the key safety problems, the motion performance and touching sea bottom of a FPSO are paid much attention by the ocean oil companies when the FPSO is exposed to survival storms in the shallow-water working areas. In this paper, timedomain numerical simulations are carried out on a 160 kDWT FPSO with a Yoke mooring system moored in the BZ25-1 oilfield with a water depth of 16.7m. The results are compared with those of the corresponding model tests. Good agreement shows that the time-domain simulations can be used to predict the performance of the FPSO in shallow-water reasonably. It is found that the touch of seabed by a fully loaded FPSO occurred few times under survival storm conditions. Therefore, the FPSO should be less loaded than that in the fully loaded condition under the survival storms. 相似文献
2.
The load and corrosion caused by the harsh marine environment lead to the severe degradation of offshore equipment and to their compromised security and reliability. In the quantitative risk analysis, the failure models are difficult to establish through traditional statistical methods. Hence, the calculation of the occurrence probability of small sample events is often met with great uncertainty. In this study, the Bayesian statistical method is implemented to analyze the oil and gas leakages of FPSO internal turret, which is a typical small sample risk but could lead to severe losses.According to the corresponding failure mechanism, two Bayesian statistical models using the Weibull distribution and logarithmic normal distribution as the population distribution are established, and the posterior distribution of the corresponding parameters is calculated. The optimal Bayesian statistical model is determined according to the Bayesian information criterion and Akaike criterion. On the basis of the determined optimal model, the corresponding reliability index is solved to provide basic data for the subsequent risk assessments of FPSO systems. 相似文献
3.
As a popular solution for mooring an FPSO （Floating Production, Storage and Offloading） permanently in shallow water, the soft yoke mooring system has been widely used in ocean oil production activities in the Bohai Bay of China. In order to simulate the interaction mechanism and conduct dynamic analysis of the soft yoke mooring system, a theoretical model with basic dynamic equations is established. A numerical iteration algorithm based on error estimation is developed to solve the equations and calculate the dynanfic response of the mooring system due to FPSO motions. Validation is conducted by wave basin experimentation. It is shown that the numerical simulation takes only a few iteration times and the final errors are small. Furthermore, the calculated results of both the static and dynamic responses agree well with those ones obtained by the model test. It indicates that the efficiency, the precision, the reliability and the validity of the developed numerical algorithm and program are rather good. It is proposed to develop a real-time monitoring system to further monitor the dynamic performance of the FPSO with a soft yoke mooring system under various real sea environments. 相似文献
4.
浮式生产储油船振动噪声混合数值预报 总被引：4，自引：0，他引：4
建立了可覆盖全频域的浮式生产储油船(FPSO,floating production storage and offloading)工作环境下振动噪声混合数值预报技术流程。将声学计算基本理论方法(有限元/边界元方法与统计能量法)应用于宽频带多噪声源的海洋工程船舶设计中,为设计能保证人员正常进行生产、生活噪声环境下的FPSO提供指导,满足国内船舶设计部门对该技术的迫切需要。文中采用声学边界元求解了FPSO上层建筑低中频域振动噪声,采用统计能量分析方法求解了高频域振动噪声,通过两种方法接力运用和不同模型间的顺利转换,实现了FPSO声学问题全频域分析。并讨论了各类方法的适用范围。 相似文献
5.
FPSO系统在深海海洋油气资源开发中扮演着重要的角色,而深水FPSO系统水下立管管路较长,立管整体重量较大,立管在水流作用下产生的涡激振动也较强,这些将给FPSO主船体带来严重的稳性、强度及疲劳问题。鉴于此,深海FPSO系统在油气资源开发过程中,须在水下一定深度设置若干水下软管支撑浮体,用以支撑来自深海海底的管线,减轻深水立管对FPSO的负载作用。随着深海资源开发的深入发展,传统水下软管支撑浮体作为FPSO系统的关键装备已经无法满足深海开采的需求,寻求大型化、深海化、生命周期长久化的新型水下立管支撑平台迫在眉睫,设计简便快捷、低风险的安装方法成为其开发过程中的重点和难点。详细描述了水下软管支撑浮体的产生及其发展历程,针对深海开发的需求提出了新型立管支撑平台的新概念,着重对新概念下下水安装更便捷的耐压立管支撑平台设计原理及其下水安装方式展开了分析,最后对水下软管支撑浮体和新型立管支撑平台的关键技术进行了总结,并提出了需进一步解决的问题。 相似文献
6.
FPSO甲板上浪研究现状 总被引：3，自引：0，他引：3
浮式生产储油轮（FPSO）是当今海洋石油开发的主流设施。FPSO通常采用单点系泊系统,船首暴露在波浪作用下,定位于特定海域进行长达数年的长期作业,上浪的风险很大。甲板上浪及其产生的载荷已是当前国际FPSO工程和研究领域的热点之一。介绍了国内外在试验研究和理论研究两方面对FPSO甲板上浪研究的进展情况,并建议我国开展这方面的研究。 相似文献
7.
A model is given for the planning of the inspection and maintenance operations of a system: an application to an offshore structure is described. The objectiveis to minimize the total cost of inspections and consequences of failures, subject to an upper boundon the total failure probability of the system. An incremental algorithm is defined for the approximate solution of the problem, and a method is described for the evaluation of the quality of any feasible solution in terms of bounds of the optimal objective value. The incremental algorithm solves the problem parametrically for certain values of the system reliability. The model has been applied to obtain an optimal inspection plan against the consequences of gross errors, accidental events, fatigue and corrosion in terms of input describing element importance values, element reliability values, error detection probabilities, error detection costs and error repair costs for parametrical variations of the structural reliability. 相似文献
8.
Precisely predicting the fatigue life of taut-wire mooring systems has become an interesting and important problem for scientists and engineers since there are still difficulties in the inspection and maintenance of mooring lines in a rough sea environment especially in deep waters. In this paper, a comprehensive fatigue analysis is performed for a polyester taut-wire mooring system of an FPSO based on the time domain dynamic theory, rainflow cycle counting method and linear damage accumulation rule of Palmgren-Miner. Three influential factors in the fatigue analysis including the pre-tension, dynamic stiffness and T-N curve are investigated in detail. Two polyester T-N curves, one is from the DNV- OS-E301 and the other is from the API-RP-2SM, are adopted in the calculation. The fatigue analysis of the mooring system after one-line failure is also carried out. The calculation results indicate that the fatigue life is significantly affected by the T-N curve. The fatigue life decreases with increasing pre-tension, and is largely reduced if taking into account the dynamic stiffness caused by cyclic loading. The analysis also proves that one-line failure has remarkable effects on the fatigue lives of other mooring lines. The present parametric and comparative study is believed to be meaningful to further understanding of the taut-wire mooring system for deepwater applications. 相似文献
9.
Owing to high costs and unnecessary inspections necessitated by the traditional inspection planning for ship structures, the risk-based inspection and repair planning should be investigated for the most cost-effective inspection. This paper aims to propose a cost-benefit assessment model of risk-based inspection and repair planning for ship structures subjected to corrosion deterioration. Then, the benefit-cost ratio is taken to be an index for the selection of the optimal inspection and repair strategy. The planning problem is formulated as an optimization problem where the benefit-cost ratio for the expected lifetime is maximized with a constraint on the minimum acceptalbe reliability index. To account for the effect of corrosion model uncertainty on the cost-benefit assessment, two corrosion models, namgly, Paik＇ s model and Guedes Soares＇ model, are adopted for analysis. A numerical example is presented to illustrate the proposed method. Sensitivity studies are also providet. The results indicate that the proposed method of risk-based cost-benefit analysis can effectively integrate the economy with reliability of the inspection and repair planning. A balance can be achieved between the risk cost and total expected inspection and repair costs with the proposed method, which is very. effective in selecting the optimal inspection and repair strategy. It is pointed out that the corrosion model uncertainty and parametric uncertaintg have a significant impact on the cost-benefit assessment of inspection and repair planning. 相似文献
10.
建立了基于风险的船体结构腐蚀优化检测规划的成本-效益分析模型。以费效比作为选择最优检测策略的标准,最优的检测策略是在保证结构设计工作寿命期内的可靠指标大于最低可靠指标的基础上,使得结构生命周期内总的费效比最大。在此基础上,以受点腐蚀损伤的船体构件为例,对其检测策略进行了成本-效益评估,并对计算结果进行了敏感性分析。结果表明,基于风险的成本及效益分析方法可以将检测规划的经济性和可靠性有效地结合起来,能够在风险与成本之间达到一种平衡,它在优化检测策略时是有效的。 相似文献
11.
FPSO水动力研究与进展 总被引：4，自引：2，他引：2
浮式生产储油轮(FPSO)是当今海洋石油天然气开发的主流工程设施。就目前国际上最为关注的FPSO水动力问题,包括深水FPSO与系泊、立管系统的耦合水动力预报、甲板上浪、FPSO与穿梭油轮组成的多浮体系统水动力、横摇运动与减摇措施、单点系泊FPSO的运动稳定性等进行了阐述,介绍了我国在浅水FPSO水动力问题上的研究进展,提出加强相关研究的建议。 相似文献
12.
Risk Based Optimal Inspection and Repair Planning for Ship Structures Subjected to Corrosion Deterioration 总被引：1，自引：1，他引：1
A framework of risk based inspection and repair planning was presented to optimize for the ship structures subjected to corrosion deterioration. The planning problem was formulated as an optimization problem where the expected lifetime costs were minimized with a eonstraint on the minimum aceeptable rehability index. The safety margins were established for the inspection events, the repair events and the failure events for ship struetures. Moreover, the formulae were derived to calculate failure probabihties and repair probabilities. Based on them, a component subjected to corrosion is investigated for illustration of the process of selecting the optimal inspection and repair strategy. Furthermore, some sensitivity studies were provided. The results show that the optimal inspection instants should take place before the reliability index reaches the minimum acceptable reliability index. The optimal target failure probability is 10^-3. In addition, a balance can be achieved between the risk cost and total expected inspection and repair costs by means of the risk-based optimal inspection and repair method, which is very effective in selecting the optimal inspection and repair strategy. 相似文献
13.
渤海油田浅水软刚臂系泊FPSO触底分析 总被引：9，自引：3，他引：6
在线性三维势流理论的基础上,采用时域计算方法对BZ25—1油田16万吨级FPSO不同吃水条件下的碰底情况作了分析研究。数值计算结果与模型试验进行了比较,两者吻合较好,说明应用时域计算方法可以从理论上预报FPSO在浅水中的触底情况。这对我国渤海等浅水海域油田应用FPSO系统进行开发具有一定的意义。 相似文献
14.
The floating production storage and offloading unit (FPSO) is an offshore vessel that produces and stores crude oil prior to tanker transport. Robust prediction of extreme hawser tensions during the FPSO offloading operation is an important safety concern. Excessive hawser tension may occur during certain sea conditions, posing an operational risk. In this paper, the finite element method (FEM) software ANSYS AQWA has been employed to analyze vessel response due to hydrodynamic wave loads, acting on a specific FPSO vessel under actual sea conditions.In some practical situations, it would be useful to improve the accuracy of some statistical predictions based on a certain stochastic random process, given another synchronous highly correlated stochastic process that has been measured for a longer time, than the process of interest. In this paper, the issue of improving extreme value prediction has been addressed. In other words, an efficient transfer of information is necessary between two synchronous, highly correlated stochastic processes. Two such highly correlated FPSO hawser tension processes were simulated in order to test the efficiency of the proposed technique. 相似文献
15.
远洋运输系统人因可靠性定量分析 总被引：2，自引：0，他引：2
远洋运输中可能发生的灾害性事故,如船舶碰撞、搁浅、腐蚀疲劳破坏、火灾、爆炸等,大多与人为失误和组织失误（HOE）有关.因此,进行远洋运输系统人因可靠性定量分析,对于运输系统的安全非常重要.针对此问题,文章结合操作风险管理（ORM）技术,对远洋运输系统进行人因可靠性定量分析.为远洋船舶提供了一套预测人为误操作的分析方法,可以降低HOE风险的发生概率,以减小事故的发生. 相似文献
16.
Artificial neural networks and their application to assessment of ultimate strength of plates with pitting corrosion 总被引：1，自引：0，他引：1
The potential for the structural capability degrading effects of both corrosion and fatigue induced cracks are of profound importance and must be both fully understood and reflected in vessel's inspection and maintenance programme. Corrosion has been studied and quantified by many researchers, however its effect on structural integrity is still subject to uncertainty, particularly with regards to localized corrosion. The present study is focused on assessing the effects of localized pitting corrosion on the ultimate strength of unstiffened plates. Over 265 non-linear finite-element analyses of panels with various locations and sizes of pitting corrosion have been carried out. The results indicate that the length, breadth and depth of pit corrosion have weakening effects on the ultimate strength of the plates while plate slenderness has only marginal effect on strength reduction. Transverse location of pit corrosion is also an important factor determining the amount of strength reduction. When corrosion spreads transversely on both edges, it has the most deteriorating effect on strength. In addition, artificial neural network (ANN) method is applied to derive a formula to predict ultimate strength reduction of locally corroded plates. It is found out that the proposed formulae can accurately predict the ultimate strength of locally corroded plates under uniaxial in-plane compression. 相似文献
17.
八角形FPSO串靠外输系统耦合动力响应分析 总被引：1，自引：0，他引：1
针对100 m作业水深的八角形FPSO,提出采用穿梭油轮串靠的外输方案,研究串靠外输在南海的适用性。建立由八角形FPSO及其系泊系统、穿梭油轮及FPSO与穿梭油轮之间的系泊大缆等组成的浮式多体动力学模型,根据多浮体动力学理论进行耦合时域模拟。在外输海况条件下,分析了串靠连接的环境适应性及研究大缆载荷的响应特性,对连接大缆的长度、刚度等关键参数进行了敏感性分析。研究表明,串靠外输的形式对于八角FPSO具有足够的安全性和可靠性,系泊大缆受到明显的冲击张力,张力的幅值受大缆的长度和刚度影响较大。 相似文献
18.
针对传统圆筒型FPSO垂荡运动剧烈的特点,提出一种带有垂荡抑制结构的圆筒型FPSO。采用1∶77.8的缩尺比制作模型,进行垂荡纵摇衰减试验,得到带有不同垂荡抑制结构模型的固有周期和无因次阻尼系数,进而选取最优的垂荡抑制结构型式。之后计算并对比传统圆筒型FPSO和新型圆筒型FPSO垂荡纵摇运动的固有周期和幅频响应函数。在此基础上,结合我国南海海洋环境条件,设计新型圆筒型FPSO的系泊系统,计算分析自存工况下的耦合动力响应,并与传统圆筒型FPSO进行对比。结果表明,文中提出的垂荡抑制结构可以有效增大系统垂荡纵摇运动的固有周期,改善运动性能,提高系泊的安全性。 相似文献
19.
Much attention should be paid to a large FPSO moored permanently in an oil field with water depth of only about 20 m, since shallow water effects on the hydrodynamics may bring about collision and damage. A 160kDWT FPSO with a permanent soft yoke mooring system is investigated with various shallow water depths and focuses are the low frequency surge motion and mooring load. Computation for the FPSO system is made based on linear 3-D potential fluid theory and time-domain numerical simulation method. Corresponding model test is carried out in the ocean engineering basin of Shanghai Jiao Tong University. It is shown that, in the surge natural period, low frequency surge motion and mooring force increase remarkably with the decrease of water depth. Especially, the smaller the ratio of water depth and draught is, the quicker the increase is. The shallow water effects should be taken into account carefully for determining the design load of a single point mooring system. 相似文献
20.
Large-scale fitting on ships of modern radiocommunication devices such as satellite, selective calling, and other equipment for communication and radionavigation, requires an assurance of availability for real-time continuous operation under the wide range of physical stresses encountered by maritime mobile units in the hostile ocean environment. Availability is a function of the reliability/maintainability of such apparatus. Since 100-percent reliability cannot be assured at this state of the technological art, the maintainability side of the formula must necessarily provide that the availability will be 100 percent, before the large capital-intensive vessels that constitute present-day merchant marine units, can depend on these modern sophisticated devices for their safety, navigation, and business telecommunications. Maintainability, in turn, results from the application of many resources (spares, test instruments, tools, technical documentation, technician personnel, etc.) for at-sea maintenance, both preventive and corrective. The key resource for the application of all the other is the technician, the skilled radio officer who must possess training and ability for in-depth analysis of malfunctions that arise, and practical maintenance and repair skills that are broad and adaptable enough to service the wide variety of new radio-electronic devices, as they are fitted. The development of such a technician-seafarer type, known as the radio-electronic officer, is discussed both historically and functionally; international actions that have been taken are delineated, and implications considered. 相似文献