• Corrosion Science and Technology
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• v.16 no.2
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• pp.76-84
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• 2017

In the construction of subsea oil and gas developments, it is increasingly common that subsea oil and gas equipment will be installed in subsea well before final hookup and production. Installation of wellheads, subsea hardware, pipelines, and surface facilities (platforms, FPSO, FLNG, connected terminals, or gas plants) are increasingly driven by independent cost and vessel availability schedules; this gives rise to requirements that the subsea facilities must be stored in the seabed for a specific time. In addition, schedule delays, particularly in the installation or startup of the connected platform, FPSO, FLNG, or onshore plant may cause unexpected extensions of the intended storage period. Currently, there are two methods commonly used for storage subsea facilities in the seabed: dry parking and wet parking. Each method has its own risks, challenges, and implications for the facility life and its integrity. The corrosion management and preservation method selection is a crucial factor to be considered in choosing the appropriate storage method and achieving a successful seabed storage. An overview of those factors is presented, along with a discussion on the internal corrosion threats and assessments.

• Bulletin of the Society of Naval Architects of Korea
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• v.49 no.1
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• pp.53-57
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• 2012

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.8 no.1
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• pp.81-86
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• 1996

Subsea pipelines have an important role in the overall tasks of offshore oil and gas production but arc exposed to various hazards with high potential risks of damage resulting in serious economic loss and impact on ocean environment. In this paper, the dynamic free span is analysed, which is one of main risk factors against the safety of subsea pipelines and the allowable length of dynamic free span which is important for the design of subsea pipelines is determined. The allowable free span length is examined by considering the relationship between vortex shedding frequency and natural frequency of pipeline free span, and the variation of the allowable length is analysed for different boundary conditions of pipe ends. The free span is regarded as a beam on elastic foundations and the boundary condition of the beam is generalized by modelling as restrained by linear and rotational spring at each end. A non-dimensionalized curve is obtained to facilitate the determination of exact allowable length of dynamic free span for subsea pipelines and is applied to the pipelines which is to be installed in the gas fields of the south of East Sea of Korea.

• Journal of Ocean Engineering and Technology
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• v.26 no.6
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• pp.86-92
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• 2012

An exploration well is drilled where oil or gas potential is shown by a seismic survey and interpretation. With the advance of drilling technology, most of the easily accessible oil had been developed by the end of the 20th century. To satisfy the ever increasing demand for oil, and bolstered by high oil prices, the major oil companies started to drill in deep water, which requires a deep offshore drilling unit. Offshore drilling units are generally classified by their maximum operating water depth. Many semi-submersible rigs have been purpose-designed for the drilling industry as the allowable drilling water depth has become deeper by the developed technics since the first semi-submersible was launched in 1963. Semi-submersible rigs are commonly used for shallow to deep water up to 3,000 m. Drilling equipment such as a top drive, blowout preventer, drawworks and power system, mud circulation system, and subsea wellhead system are explained to help with an understanding of offshore drilling procedures in the oil and gas fields. The objective of this paper is to introduce the main components of a semi-submersible rig and, by doing so, to raise the awareness of offshore drilling, which accounts for over 30% of the total oil production and will continue to increase.

• Journal of the KSME
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• v.54 no.11
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• pp.32-36
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• 2014

이 글은 기존 FPSO(부유식 원유 생산저장하역설비: Floating Production Storage and Offloading)방식과 Pipeline을 이용한 Subsea Tie-back방식의 단점과 한계점을 극복하기 위해, 대형 해저저장탱크를 이용한 신개념의 심해유전 개발 시스템에 대해 소개한다.

• Ocean Systems Engineering
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• v.6 no.3
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• pp.289-303
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• 2016

With more than 100 years exploration and development of offshore oil, more and more offshore oil fields will gradually lose the economic profit to operate. In this article, to take the target oil field for example, the procedure of decommissioning for FPSO, TCMS, subsea system and well abandonment have been analyzed. Meanwhile, the environment impact and mitigation measure have been proposed. The successful project experience will provide a guide line for the offshore facilities decommissioning and abandonment.

• Geophysics and Geophysical Exploration
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• v.17 no.1
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• pp.34-44
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• 2014

Because offshore plant industry needs to design, deploy and operate much of equipment especially, the latest trend shows the installation of production facilities is augmented in the subsea. The installed facilities are very difficult to be repaired or changed because they are located in the subsea. For solving these problems, both the directly related information of the production like the optimal number, position and depth of wells and the distribution for effective operation and safety of equipment of subsea should be considered at the preliminary stage of FEED (Front End Engineering Design). The marine exploration is introduced in this paper for providing the fundamental technology to answer the questions related to above considering points. First, some kinds of the offshore plant facilities are enumerated and aims of marine exploration for the offshore oil/gas development are summarized. In addition to it, the main roles of marine survey, in the step of designing and installing offshore oil-gas plant, development are briefly listed. And then foreign examples are shown to help the reader's understand. This paper is hoped to be helpful for understanding the marine exploration that can be applied to offshore oil/gas plant and to be contributed to developing the domestic techniques in this field for the future.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.6
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• pp.662-669
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• 2015

There has been an increased interest in the mitigation of wax deposition because wax, which usually accumulates in subsea oil-production systems, interrupts stable oil production and significantly increases the cost. To guarantee a required oil flow by mitigating wax deposition, we need to obtain a reliable estimation of the wax deposition. In this research, we perform simulations to understand the major mechanisms that lead to wax deposition, namely molecular diffusion, shear stripping reduction, and aging. While the model variables (shear reduction multiplier, wax porosity, wax thermal conductivity, and molecular diffusion multiplier) can be measured experimentally, they have high uncertainty. We perform an analysis of these variables and the amount of water and gas in the multiphase flow to determine these effects on the behavior of wax deposition. Based on the results obtained during this study for a higher wax porosity and molecular diffusion multiplier, we were able to confirm the presence of thicker wax deposits. As the shear reduction multiplier decreased, the thickness of the wax deposits increased. As the amount of water increased, there was also an increase in the amount of wax deposits until 40% water cut and decreased. As the amount of gas increased, the amount of wax deposits increased because of the loss of the light hydrocarbon component in the liquid phase. The results of this study can be utilized to estimate the wax deposition behavior by comparing the experiment (or field) and simulation data.

• Computational Structural Engineering
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• v.17 no.2
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• pp.50-59
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• 2004

The Thunder Horse semi-submersible intended for production of hydrocarbons at Thunder Horse field in the Gulf of Mexico(GOM), Mississippi Canyon Block 778. The field is located in water depth of 1850m, 240km SE of New Orleans.(ref. Fig.1) These areas have estimated 1.5billion barrels reported. Also there are world class subsea hardwares with 15ksi Guideline less Trees, High pressure 8-12" Flow lines, Insulated Steel Catenary Risers with Flexible Connectors, 150km of Flow lines, and 100km Control & Injection Umbilicals(ref. Fig.2). (omitted)

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2011.10a
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• pp.127-127
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• 2011