ABSTRACT Nowadays, due to continuous growth of the computational capacity, there is tendency to perform complex numerical simulations, which are highly interesting to compare with analytical estimations and experimental investigations. The analysis of the evaporation rate of liquefied natural gas (LNG) from the closed cargo tank with valve has been studied by means of numerical simulation based on the finite volume method. The numerical models have developed for a different environment conditions for the case of real gas. Additionally, the heat transfer mechanisms within the closed cargo tank are considered the calculation results are presented and compared with known experimental data in this work. INTRODUCTION AND STATEMENT OF THE PROBLEM During the sea passage the evaporation of the LNG from the tank is taking place. That happens due to particularity of energy transport within the tank's isolation. Liquefied methane is transported at a temperature about the boiling point T CH4 = − 163 ◦ C; however the temperature outside of the tank is equal to the ambient temperature. During the transportation the ambient temperature changes according to the region when the cargo moves (Amid, 2016). According to the different data sources the average ambient temperature is defined as: For the whole world, excluding Alaska the air temperature is given in the range (at 5 knot) from −18 ° to +40 ◦ C; For Alaska the air temperature is given in the range (at 5 knot) form - 29 ◦ to + 10 ◦ C. The ambient temperature in this work is taken in the range from − 20 ◦ C to +40 ◦ C, (Amid, 2016). The transported system should sustain the total vapor pressure of cargo or to hold on the pressure within the cargo below the specified pressure. The vessels for the methane transporting must keep this condition as least 21 days. There are several ways to provide a stable work of this system: liquefaction of steam combustion in a boiler or catalytic preheater, the use of steam as a fuel, a combination of these methods.

ABSTRACT Sloshing impact loads have been reported repeatedly throughout the lifetime of the ship. However, a study on the mechanical performance of polyurethane foam with repetitive impact load has not been conducted despite the necessity of evaluation. Therefore, in this study, the effect of repetitive impact loading on mechanical behavior of LNG insulation panel was investigated. To do this, a series of drop impact test was performed on two types of LNG insulation panels with polyurethane foam and glass fiber reinforced polyurethane foam. After the impact test, evaluation of cryogenic mechanical behavior was conducted. INTRODUCTION As the global demand for liquefied natural gas to pursue clean energy increases, the capacity of the LNG carrier is increasing, which can cause serious damage on the membrane insulation system. Sloshing is a violent resonance motion of a free surface inside a moving CCS. Moving liquid will force the containment system wall. Severe and violent sloshing typically occurs when the vessel moves with motion periods close to the highest sloshing resonance period for the liquid in the cargo. Failure of LNG CCS can lead to massive loss of human and material resources, so robust design and production of LNG CCS is essential. In this reason, various types of insulation systems have been proposed to store LNG. The structures consist of a primary barrier of metallic material to prevent leakage of cryogenic fluids and a composite material insulation panel to control the vaporization due to the temperature rise. Insulation panel is made of plywood and polyurethane foam as main materials and also undergoes fluid impact such as sloshing. Polymeric foam such as polyurethane foam (PUF) and glass reinforced polyurethane foam (RPUF) has been widely employed as insulator in industry because of its low thermal conductivity, low permeability and light weigh. Furthermore, the volume of polymeric foam does no change due to temperature gradient. PUF is fabricated from the isocyanates and polyols which RPUF is the mixture of high density polyurethane foam and chopped glass fiber.

ABSTRACT For the conceptual design of Floating LNG Bunkering Terminal (FLBT), three vessels with different LNG cargo capacity can be side by side moored to FLBT. For the purpose of designing the mooring line and dynamic positioning (DP) system for FLBT, the environmental load must be taken into account during the initial design phase. In order to obtain the wind and current load coefficients, wind tunnel tests for vessels in multi-body arrangement were carried out at FORCE Technology. In case of current load, additional model tests were performed in the ocean engineering basin at the Korean Research Institute of Ships & Ocean Engineering (KRISO). Furthermore, the wave drift force was measured in the basin tests by simulating the regular wave conditions. Overall results were compared and contrasted with CFD results to analyze the validity of obtained results. Finally, total environmental loads acting on the FLBT were calculated from the loads acting on each of the floating bodies to evaluate the DP capability and mooring line analysis. INTRODUCTION Enactment of the regulation on sulfur emissions set by IMO has emphasized the need of the liquefied natural gas, LNG as a fuel for offshore vessels, and this has soared up the demand for the LNG fueled vessel. To supply the LNG fuel to vessel, bunkering terminal process needs to be carried out, where it can either be performed at land and offshore. Regarding the offshore bunkering process, a national R&D project funded by the Korean government, is being carried out by Korea Research Institute of Ships and Ocean Engineering, KRISO to allow operating vessels to receive a vast amount of fuel at once without risking the onshore living from the potential LNG explosion. Such offshore bunkering process involves the number of vessels to operate simultaneously with the 220k FLBT, namely a 170k LNG carrier, 30k and 5k LNG bunkering shuttles. The operating procedure of LNG bunkering is as follows. As the 170k LNGC delivers the LNG fuel to the FLBT, moored with the turret mooring system near shore, it can load and store the fuel for a certain period of time at the same time as unloading it to 30k and 5k LNGBS, where those bunkering shuttle can deliver the fuel to the LNG fueled vessel.

ABSTRACT With the increase of human activities at sea, it is inevitable that anchors drop into the water due to operating errors, which may lead to failure of pipelines and cause economic damage and environmental pollution. Previous methods of related analysis are mostly based on the DNV-RP-F107 recommended method (hereinafter referred as DNV method). DNV method hardly considers the variation of anchor's size and weight. And it is insensitive to the pipeline geometry and material properties. Based on reliability theory, DNV method is improved to calculate failure probability under the consideration of the above relevant factors. The efficiency of the proposed method is verified by a practical case. Besides, analysis of the influence of various factors on pipeline failure probability is completed in this paper, including anchor weight, size, pipeline geometry and material properties, the distance from the anchor drop point. Meanwhile, considering the variability, the sensitivities of variables to the failure probability are discussed. Study results indicate that the failure probability calculated by DNV method is underestimated in some situations, which can probably cause a loss for pipeline projects. Whereas the proposed method is able to consider much more influences and leads to reasonable results consistent with the actual situation. INTRODUCTION Submarine pipeline is seen as the ‘lifeline’ for offshore oil and gas industry. Pipeline safety is one of the most important problems for engineering practice. Recently, anchors dropping into the sea becomes more frequent due to the increasing human activities at sea. The dropped anchors are likely to impact on pipelines and lead to pipeline failures, which can cause economic damage and environmental pollution. In order to reduce the risk and provide safe design, considerable research efforts have been devoted to risk assessment and reliability analysis of pipelines. In general, methods of the relevant research mainly consist of two categories: one is qualitative analysis, which can study the main influence factors on pipeline failures. Among them, fault tree analysis (FTA) is the most popular methodology and has been extensively applied to pipeline failure analysis. (Wang et al., 2007; Dong et al., 2005; Lavasani et al., 2011). The other one is quantitative analysis, which can determine pipeline failure probability and provide reliable reference for safe design. Katteland et al. (1995) developed a model for risk calculation, and applied it to evaluate the risk of all the installations in the North Sea. Det Norske Veritas (2010) proposed a ubiquitously used method for pipeline risk assessment and failure probability calculation (DNV method). Based on statistics of crane accidents, Det Norske Veritas (2013) also gave the falling probability for typical loads and various objects, which provided abundant references for pipeline risk assessment. On the basic of the above research, Liu et al. (2005) proposed a model to calculate the probability of pipeline being impacted under various anchorage conditions. Ding et al. (2010) modified DNV method and made a risk assessment of pipelines due to third-party activities. Yan et al. (2014) proposed a procedure to estimate the pipeline failure probability caused by anchoring activities. Up to now, to the best of the author's knowledge, quantitative analysis methods are mainly based on DNV method. In some situations, this method is hardly to consider the effect of anchor size and weight on pipeline failure probability. What's more, it is insensitive to the effect of pipeline geometry and material properties, which is not consistent with practice and may cause errors. In order to give an insight into those effects, a method based on reliability theory to calculate pipeline failure probability is proposed.

ABSTRACT DSME has recently developed a new membrane type cargo containment system, SOLIDUS, and launched it to the LNG market. The system has double metallic membrane barriers to increase safety and adopted a newly developed reinforced polyurethane foam as insulation material. The integrity of the system in terms of ultimate strength has been proved by comparing the calculated minimum safety factors with the required values while the obtained minimum fatigue life of primary and secondary membranes has shown that the system has enough fatigue strength. The system's sloshing resistance has also been verified by the obtained utilization factors smaller than the requirement. INTRODUCTION With the effort during the past few years together with its experience and technology in LNG industry, DSME recently has developed its new membrane type cargo containment system (CCS), SOLIDUS, and officially launched the new system into the LNG market claiming to a safe and economic membrane type CCS. SOLIDUS is a market driven product following the demand of less cost and less boil off gas but higher safety. Those requests have been fulfilled by lowering the product loyalty, by employing the newly developed reinforced poly-urethane foam (R-PUF) of high performance and by utilizing the double independent metallic barriers, respectively. In this paper, it is focused on the technical excellence of SOLIDUS by explaining the engineering works involved in the development of the system leaving behind the symbolical value it has brought into the LNG market. SYSTEM OVERVIEW OF SOLIDUS SOLIDUS is a next-generation membrane type cargo containment system which consists of two layers of insulation panels (sandwich type made of plywood, R-PUF and plywood) and has double metallic barriers satisfying the International Gas Carrier (IGC) code. The primary membrane is 1.2 mm of SUS 304L and the secondary membrane is 0.7 mm of invar. Both membranes have corrugations to alleviate burdens from the thermal contraction due to cryogenic cargo. The insulation panels with primary of 100 mm and secondary of 300 mm thickness are installed to meet the market need for low Boil-Off Rate (BOR). An eco-friendly and high-performance insulation material, R-PUF, that has been developed in cooperation with the German chemical company, BASF, is utilized to lower BOR and satisfy strength requirements. The system is designed to be secured to inner hull via mastic bonding on the bottom of the secondary panel and a mechanical securing module is devised for securing of the primary panel with the secondary panel. The basic characteristics of the SOLIDUS system are shown in Fig. 1.

ABSTRACT The impact of dropped objects and trawl board on submarine pipelines are simulated by a non-explicit finite element method. The new method works in three mechanics. The impact process is simulated by adjusting the material properties. The damage of the pipeline is solved using Cowper-Symonds equation. Drucker-Prager model is used to analyze the elastic-plastic properties of soil under impact. Then the present work can take into account the interactions among the dropped objects, pipelines and soil. Furthermore, the effects of the weight, shape, impact velocity and seabed flexibility are discussed in detail. INTRODUCTION Submarine pipelines are the "lifeline" of offshore oil and gas production system and are used as one of the primary ways to transport oil and gas for offshore development. The risk of pipeline leakage is increasing with the rapid expansion of submarine pipeline networks. Statistically, more than 50 percent of submarine rupture accidents are caused by third-party damage such as ship anchoring and trawl fishing (Famiyesin et al., 2002; Cao et al., 2010; Ivanovic et al., 2011). In order to reduce the damnification to submarine pipelines caused by third-party damage, the pipelines need to be buried into sea floor reasonably. It is necessary to investigate the deformation of the submarine pipelines for designers. DNV-RP-F107 (Det Norske Veritas, 2002) gives an empirical formula for the dent depth of the pipelines impacted by dropped objects (Alexander, 2007). However, this specification does not consider the absorption of the impact energy by seabed and soil covered on the pipelines, resulting in a conservative assessment. Some scholars have explored the response of submarine pipelines to the impact of dropped objects. The interaction between pipe and soil is a complex process which contains complex mechanism and thus evaluating the damage on submarine pipelines caused by dropped objects is quite complicated. Alsos et al. (2012) discussed the importance of impact velocity and mass during impact, and found that global deformations would be triggered, which implied that the dissipated energy going into local denting is reduced to a fractional value. Yu et al.used a three-dimensional numerical method to study pipeline deformations due to transverse impacts of dropped anchors and the dent depth of the pipe was estimated by the local Galerkin discretization method. The results showed good consistency with experiment. Zeinoddini et al. (2013) carried out a parametric study to examine the effect of bed flexibility and the results showed that the flexibility of seabed plays an important role in impact energy dissipation. Ryu et al. (2015) investigated pipe-soil interaction using finite element technology in which the soil was simulated using the Mohr-Coulomb failure criterion. Robert (2017) used a modified Mohr- Coulomb model to simulate the behavior of pipelines in unsaturated soil. The model was developed considering microscopic and macroscopic suction hardening mechanisms and was implemented into a commercial finite program.

Abstract In bad weather conditions, manoeuvring of a liquefied natural gas (LNG) carrier in open sea at floating LNG (FLNG) terminals can be associated with operational risks of potential consequences to human safety, environment and economy. Due to limited knowledge and experience with the FLNG technology, it is difficult to perform risk evaluations. Expert judgments are often employed to analyse and assess LNG risks using the risk matrix technique. However, human behaviour may influence the outcome of risk analyses resulting in an uncertain risk level. To deal with the uncertainty of expert opinions, two fuzzy set approaches are introduced in this paper. The first is a rule-based fuzzy model using Sugeno method for fuzzy inference. The second is a trapezoidal fuzzy set approach " simplified approach". Risk parameters were translated into a number of fuzzy sets, and a fuzzy risk value was calculated for several hazardous scenarios at different phases during ship berthing operations. The calculated fuzzy risk values were found to be consistent with the results of risk matrix technique. Introduction The development of Floating Liquefied Natural Gas (FLNG) terminals is one of the practical and cost-effective solutions to the current challenges in the export of offshore natural gas. However, hazards during manoeuvring LNG carriers in the vicinity of these terminals can have severe impacts on the safety of life, environment and installations, particularly in bad weather. For instance, during berthing tug assistance may be insufficient to pull the LNG carrier into a desired position during such conditions thereby the scenario of collision between the LNG and FLNG vessels is highly expected due to a small proximity between the two vessels (Antao and Soares, 2012).

Abstract This paper introduces the Shenzhen-Hong Kong submarine pipeline of West to East Gas Pipeline II Project. In specific environmental conditions and submarine pipeline's situation, we carried on the risk identification for pipeline suspending, drop anchor impacting and ship aground impacting. Consequence of failure is given out relating to pipeline suspending, drop anchor impacting and ship aground impacting. Pipeline risk probability is determined. Some specific measures are put forward to guard against submarine pipeline risks take place.

Abstract Development of transport and logistics infrastructure is one of the key factors of the economic growth and natural resources development in the regions of the Russian Arctic. Marine transport system and first of all the Northern Sea Route (NSR) are import parts of Arctic transport complex. The authors underline the growing role and the significance of the NSR. Arctic ports provide the life and activity of the population of the Arctic zone of the Russian Federation (AZRF), transfer coasting freights and foreign trade freights. The most important Russian Arctic ports and perspectives of their development are studied. The authors present the main directions of the transport and logistics development in Arctic basin according to the new Russian Port Infrastructure Development Strategy for 2030. Forecasts of port capacities which take into account prospective projects in the Russian Arctic regions are given. In Russia the share of the Arctic ports in transfer of freights by 2030 can attain 13%. The most perspective directions of development of coastal port infrastructure of the AZRF are shown. Modernization and development of the port and technical fleet including service and auxiliary vessels of different functions could provide effective work of sea transport on approaches to ports and in ports. Development of transport and logistics infrastructure in Russian Arctic basin could provide high level of cargo operations in the region, ecological safety and safety of marine navigation in Arctic.

Abstract For the safety design requirement, analysis of the airflow field within LNG ship engine room is necessary. The CFD analysis for equipment within the engine room is a complex calculation problem due to quality and efficiency. This paper provides an easier method to check the design of ventilation system. Species transport model is adopted to simulate methane-air mixture. Several conclusions are given including velocity maps. CFD simulation of ventilation test is proposed here to give out a clearer view of airflow distribution.

ABSTRACT: The phenomenon of statistically significant decrease in static limit of fluidity (normalized to background temperature) of heavy oil product М-100 is found in near-wall layer of rotating pipe. This effect is induced by shear ultrasonic oscillations of the pipe with the frequency of 25 kHz. The phenomenon is revealed by means of modeling laboratory installation where temperatures were in a range from -13oC up to -17.5oC. The value of the effect is about 19% under acoustic power of ultrasonic oscillations of an order 0.002 W/cm2. This effect represents practical interest in decreasing extreme starting loads on pumps of technological pipelines especially in polar or pre-polar winter conditions. The result may be also important for crude mineral oil pipeline transportation from polar and pre-polar fields. INTRODUCTION Heavy oil products, in particular, furnace fuel oil, are transported in the technological pipelines of tank farms and thermal power stations. A problem is the weak fluidity of heavy oil products, especially at low ambient temperatures, when they become jelly-like. Special problems arise at starting modes when heavy oil products, at least, in a near-wall pipe layer undergo transition from elastic to fluid status. Usually a steam heating is applied to increase fluidity, however this technology is very energy consuming and ineffective owing to high insulating properties of heavy oil products. A number of studies were devoted to investigation of mechanical oscillations influence on oil fluidity. Lionetto et al. (2007) observed decreasing oil gelation under increase in intensity of ultrasonic oscillations. Mironov et al. (2002) showed an effect of double decrease in flow resistance in oil at temperatures nearby -7oC by means of creation of shear ultrasonic oscillations in wall of pipeline. Thus, the effect of acoustic influence on fluidity of mineral oil with a temperature of fusion up to 29оC was confirmed experimentally.

ABSTRACT: Green ship using LNG for fuel has emerged as new trend recently due to increasing environmental regulations in the world. This is the reason for continuous active research of LNG Tank. IMO type " B" independent LNG cargo tank has received attention in order to get over limitation of membrane type LNG cargo tank. In this paper, global FE analysis was carried out in order to find out structural considerations of IMO type ‘B’ LNG cargo tank. INTRODUCTION The demands for natural gas as clean energy are rapidly increasing worldwide. Such demand is due to the increase in the construction of large LNG Carrier and LNG Floater. The demands of natural gas in energy market have been growing for last severe years, and the growth continues for next few decades. For the reason, the construction orders for large LNG Carrier and Floater are continued. Since the medium to long-term forecasts predict a shortage of LNG in onshore production base, offshore LNG production has been emerging as alternative for the future. Market of membrane type cargo containments system (CCS) is strong for LNG Carriers. However, constraints of NO96 Type CCS have been reported like filling limit caused by sloshing impact and vulnerableness to external impact. For the reason, many concerns are focused on IMO type " B" independent cargo tank for LNG FPSO, arctic LNG Carrier and fuel tank of LNG fueled vessels. As IMO type " B" tank can be filled partially and strong on sloshing impact and external impact, the tank is especially taken into account appropriate for LNG FPSO and arctic LNG Carrier. In this study, strength and buckling assessment for STX's own IMO type " B" Tank (ITS: Independent Tank of STX) was carried out by global FE analysis using Floating Offshore Liquefied Gas Terminals Program (FLGT) of ABS.

ABSTRACT: With worldwide LNG demand increasing rapidly, LNG liquefaction plants and liquefaction processes are a highly valued industry. Recently, there has been an increase in research and development of LNG-FPSO technologies for offshore liquefied natural gas (LNG) service instead of land-based LNG plants. While onshore LNG facilities have traditionally focused on power efficiency as a key criterion for process design and equipment selection, offshore LNG would require not only power efficiency but also safety and compactness. A new natural gas liquefaction cycle is proposed in this paper. The structure of the new cycle is based on the SMR (Single Mixed Refrigerant) liquefaction cycle which has a very simple structure, and butane and/or pentane have been added to the refrigerant to increase the efficiency of the cycle. In the proposed cycle, a distillation column is used to separate mixed refrigerant into HK (Heavy Key) and LK (Light Key) components. HK refrigerant is used for pre-cooling the natural gas, and the natural gas is liquefied and partially sub-cooled by LK refrigerant in the cryogenic range of the heat exchanger. Since the proposed liquefaction cycle has a simple structure with high compactness and power efficiency, the proposed cycle could be suitable for the LNG-FPSO liquefaction process. INTRODUCTION Thermodynamic process for the liquefaction of natural gas has evolved since 1970's (Barron, 1985; Roberts, 2002; Andress, 2004; Flynn, 2005; Venkatarathnam, 2008; Chang, 2009) in order to meet a number of challenges, including the demand of greater efficiency and larger capacity. Natural gas is cooled-down to LNG temperature in thermal contact with closed-cycle refrigerant(s). In order to reduce the input power for liquefaction, it is crucial to reduce entropy generation due to the temperature difference between hot stream (including feed gas and hot refrigerants) and cold refrigerants in the heat exchangers.

ABSTRACT: FPSO (Floating Production Storage and Offloading) for LNG industry is a promising efficient method compared to onshore NG (Natural Gas) treatment facility when the well is located in offshore ocean. The heat exchangers in FPSO should be compact and effective due to limited topside area. PCHE (Printed Circuit Heat Exchanger) is considered for application for MCHE (Main Cryogenic Heat Exchanger) in FPSO due to its compactness and high effectiveness. This paper present the idea of utilizing PCHE for LNG-FPSO facility. The design issue of cryogenic PCHE has been discussed and the detailed performance factors of the preliminary designed PCHE have been experimentally examined. INTRODUCTION LNG (Liquefied Natural Gas) implies the liquid state of natural gas, which is liquefied at temperature around -161 °C (112 K) (Waldmann, Bettina., (2008)). The composition of NG (natural Gas) depends on the well where it is extracted, but most of NG consists of methane (CH4). LNG has advantages for transportation and energy density. South Korea's LNG demand is currently increasing like the world's LNG demand. LNG was the source of 25% of world energy consumption at 2005, but this demand will be increased up to 50% in next ten years. Because 20% of natural gas wells are under the sea, the offshore gas plant development is revaluated as one of the promising energy industries. FPSO (Floating Production Storage & Offloading refines, liquefies and stores natural gas from the sea. This LNG production method has a big advantage in that it does not need to transfer natural gas from offshore place to onshore plant to liquefy it. FPSO can also transport LNG to another ship, which is cost effective. The compactness and lightness can be achieved by using proper equipments. One of the large equipments in LNG plant is a heat exchanger.

ABSTRACT: This study aims the investigation of depth effects in the motion response of floating structures. To this end, a Rankine panel method adopting higher-order B-spline basis function is applied in time domain. The topology of sea bottom is assumed to be either constant or varied. Taking the advantage of the Rankine panel method, any bottom topology near floating structures can be considered by distributing the solution panels on the bottom surface. The numerical analysis includes the radiation, diffraction problems and floating motion responses for typical hull forms, e. g. LNG carrier and barge. The result is compared with other numerical solution for validation purpose. The motion RAOs are observed for different water depth and varying bottom topology. INTRODUCTION Recently moving inland facilities into coastal area is seriously considered. In coastal area, water waves and floating-body motion have different property by restricted water depth. Therefore considering bottom effect is important to predict the motion responses of such coastal platforms. The motion responses of floating bodies in constant depth have been considered as one of classical problems in marine hydrodynamics, and several methods have been introduced. For instant, strip method has been utilized by Tuck (1970), Tasis et al. (1978), Andersen (1979), Perunovic and Jensen (2003). This method is still used nowadays for practical purpose, however it has limitation as a two-dimensional theory. To complement such limitation, Kim (1999) introduced a new unified theory for the finite-depth effect, showing much improved accuracy. Nowadays, three dimensional panel method programs such as WAMIT (Lee, 1995), which contains solution procedure for constant depth, are available. For an offshore structure, Teigen (2005) has showed motion responses of floating barge over constant and sloped bottom. Ship motion over sloping bottom has been considered by Buchner (2006), Ferreira and Newman (2008) and Hauteclocque et al. (2009).

ABSTRACT: Risk assessment is a relatively new technical field and dissimilar from traditional divisions of engineering such as civil, mechanical, chemical, and aeronautical. It applies to all of them and belongs to none. Nowadays, in offshore area, risk assessment became an important item (tool) to check the rule & regulation and to verify a new design, construction way and operation activity, etc. This paper presents the severity of major hazards at initial design stage of LNG-FSRU. First of all, we did HAZID study to get every possible hazardous event that we can imagine from structural lay-out and operational activity of LNG-FSRU. Second, we tried to find major accidents and its scenarios which can cover serious or typical events (accidents) identified from HAZID study and offshore accident records. Third, a numerical analysis (consequence analysis) was carried out to evaluate the severity of each scenario including major accidents. Finally, we suggested several prevention and mitigation methods to decrease the present risk. INTRODUCTION LNG-FSRU (Floating Storage and Re-gasification Unit) is a new concept to supply a natural gas from offshore re-gasification plant to onshore consumer. It has been proposed as alternatives to traditional onshore re-gasification plants. The concept of LNG-FSRU has been studied and developed as a new LNG supply facility for a long time, caused by the FSRU concept having several benefits over the land based re-gasification facility. One great advantage is the flexibility for location with minimum or no construction at onshore. It means that the obstacles in public acceptance are less than the onshore re-gasification plant. Another advantage is the easiness of LNG-FSRU construction in the modern major shipyards, covering all key functions such as procurement, material supply, construction, mechanical completion and testing. Also the LNG-FSRU will have the benefit of being able to move other places.

ABSTRACT: Dynamic load acting on side-by-side mooring system is one of key factors to estimate the offloading operability of the LNG FPSO. In this paper, a numerical mooring analysis for the side-by-side moored LNG FPSO is carried out. As input data for mooring analysis, two-body motion responses are computed using a three-dimensional diffraction/radiation program. Wind and current loads including shielding effects are also applied to the mooring analysis. Results of the mooring analysis are validated by a comparison with another numerical program. In order to estimate the STS(ship to ship) offloading operability, dynamic loads acting on the side-by-side mooring system are calculated for two different mooring system configurations. Through the present study, it is found that the calculation results of two numerical programs are almost similar. INTRODUCTION As the demand of natural gas is increasing, a LNG-related offshore plant such as LNG FPSO(Floating Production Storage and offloading) and LNG FSRU(Floating Storage and Re-Gasification Unit) is receiving much attention these days. In case of the LNG-related offshore plant, a side-by-side offloading system is applied instead of a typical tandem offloading system. The side-by-side moored vessels show different characteristics from the tandem moored vessels. Hydrodynamic interaction between the vessels is highly increased and it gives an effect on relative motion and drift forces due to their close proximity (Kim and Ha, 2002, 2003, Ha and Kim, 2004). The shielding effect on current and wind load is another important consideration (Yuck et al. 2007). This paper presents a numerical investigation on the STS (ship-to-ship) offloading operability for the side-by-side moored LNG FPSO and LNG carrier. A two-body motion analysis is carried out by a threedimensional hydrodynamic analysis program. In order to estimate the accurate offloading operability, dynamic load acting on the mooring system is computed considering motion responses of vessels and environmental load.

ABSTRACT: Liquefied natural gas has the unique distinction of being the only flammable or hazardous material. Inspection effectiveness may be introduced into the probability of failure calculation by using Bayesian analysis or more directly by modifying the model for the independent variables, the distribution function and parameters, such as mean and coefficient of variation, changed based on the NDE method and coverage used during an inspection. Available failure data from the LNG industry are often statistically unreliable. Therefore, we need to improve more accurate information data. NDE reliability matrix is to apply optimization method of the NDE method. Environment parameters consist of inspector qualification and experience, test condition and inspection reliability parameters are composed of the inspection method and process method, such as UT, ET, RT and s/n ratio, signal processing method, etc. Finally, this paper purposes that the Reliability matrix is a powerful tool for risk assessment of not only the LNG industry but also in other industry. INTRODUCTION Liquefied natural gas is simply a convenient form of natural gas, a cryogenic liquid condensed in volume to make storage economically feasible. LNG is made at a liquefaction plant is restored to a gas at a regasification plant. In a liquefaction plant, there are several steps. The main steps, starting at the natural gas feed, include CO2 removal, dehydration and mercury removal, initial chilling, liquefaction, nitrogen rejection, finally, product LNG storage. LNG is a liquid mixture of light hydrocarbons. The main component is methane C1. And there have a other minority components such as nitrogen N2, ethane C2, propane C3, and traces of i-butane iC4, nbutane nC4, i-pentane iC5, n-pentane nC5(Mario and Rafael, 2010). The largest amount of LNG imported in 2005 was 58.6million tons to Japan, or 30% of the world trade in LNG.

ABSTRACT: This study focuses on the comparisons of liquefaction technologies in LNG plant. And study findings suggest a strategy for effective liquefaction process design. The best process requires less power and handles larger capacity. One of the key challenges in LNG plant is to get the optimal design of liquefaction process according to the costbenefit analysis for each process. To design the liquefaction process, our team changed main equipment conditions. Our team made models of various commercial liquefaction processes. In this paper, both modeling and optimization in liquefaction process were carried out to obtain liquefaction process efficiency improvement. INTRODUCTION Despite numerous attempts to develop alternative energy, oil is the most dominant source of energy in the global energy market. But, the global energy market structure has been changing sharply because of environmental restrictions. The natural gas is growing rapidly in the global energy market. Natural gas is a clean source of energy and is preferred because it offers a number of significant environmental benefits over other fossil fuels such as oil and coal. The global use of LNG is increasing sharply. World LNG demands expand from 159 million ton in 2006 to 500 million ton in 2030, achieving 3.6- fold growth. Because much of the gas reserves in the world are found in offshore fields, gas found offshore is brought onshore to be processed and liquefied at about -160°C for export. Traditionally, natural gas trapped offshore is transported to the land by the local seabed pipelines, which become economically challenging in remote or deep water locations. FPSO is a floating vessel that is designed to receive oil or gas produced from nearby platforms or subsea template, to process it, and to store it until oil or gas can be offloaded onto a tanker or transported through a pipeline.

ABSTRACT: The Samcheok LNG receiving terminal of Korea Gas Corporation is the fifth LNG terminal in Korea which is located in east coastal area of Korea. According to long-term gas demand in Korea, KOGAS decided to construct the Samcheok LNG terminal to provide gas to North-East of Korea. This terminal has a storage capacity of 2,400,000 m3 in 12x200,000 m3 9% nickel containment LNG storage tanks and a gasification capacity of 2,340 ton/h. This terminal will have a berth capacity for 270,000 m3 LNG carriers. The start-up of the terminal is targeted for 2013. The first phase of construction for 9 LNG storage tanks of 200,000 m3 with gasification process of 780 ton/h will take place from 2013 to 2014. The send-out process can be extended to a capacity of 2,340 ton/h. This project will be developed in phases with consideration being given to future expansion. This paper describes the key aspects of design and features of Samchuck LNG terminal whose construction was initiated in early 2010. We also show the unique engineering aspects associated with the facility's process design and storage tank design. INTRODUCTION The Samcheok LNG receiving terminal of KOGAS which is currently undergoing construction is located in the vicinity of Samcheok city, Korea. The Samcheok LNG receiving terminal is the fifth LNG terminal in Korea which is located east coastal area of Korea. According to long-term gas demand in Korea, KOGAS decided to construct the Samcheok LNG terminal to provide gas to North-East of Korea. This terminal has a storage capacity of 2,400,000 m3 in 12x200,000 m3 9% nickel containment LNG storage tanks and a gasification capacity of 2,340 ton/h. This terminal will have a berth capacity for 270,000 m3 LNG carriers. The start-up of the terminal is targeted for 2013.