• Journal of the Korean Society of Industry Convergence
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• v.24 no.6_2
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• pp.763-772
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• 2021

Drilling Mud Treatment Systems are widely used for Oil Gas drilling mud circulation, horizontal directional drilling mud recycling, geothermal drilling, mining, coal exploration drilling, water well drilling. Degasser is a device used in drilling to remove gasses from drilling fluid which could otherwise form bubbles. For small amounts of entrained gas in a drilling fluid, the degasser can play a major role of removing small bubbles that a liquid film has enveloped and entrapped. As with the desander, its purpose is to remove unwanted solids from the mud system. The smaller cones allow the desilter to efficiently remove smaller diameter drill solids. In this study, a simulation study is conducted on the degasser of the facility in the Mud Treatment System to conduct a performance review on the gas separation in the mud.

• Transactions of the KSME C: Technology and Education
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• v.4 no.2
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• pp.85-92
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• 2016

During ballast of a LNG carrier, the mud at the sea floor can enter the tanks together with the ballast water if the LNG terminal is located at shallow water region. In order to remove the mud deposited on the tank floor during deballasting, the mud flushing system in the ballast tanks is applied. In this study, various analyses to conform the efficiency in the mud removal are performed. In order to design the mud flushing system, the particle size of the mud is measured by particle size analyzer. Flushing performance is evaluated by numerical analysis. From the results of numerical analysis including flow field and piping system network, the optimized flushing system is determined.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.463-470
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• 1999

The railroad transportation system has more advantages over other transportation systems in terms of low cost, safety and mass transportation The development in economy and social environments lead to the increase of the transportation between cities. As a result, the increased capacity of transportation system is required and maintenance of transportation facilities becomes more important, In the railroad system mud-pumping is one of the troubles to cause distortion of rails and progressive disrupture of subgrade. h this study, SASW measurements were performed to investigate stiffness structures at the sites with mud-pumping and without mud-pumping, Comparison of the stiffness structures revealed the mechanism of mud-pumping and provided information to choose measures for the mud-pumping.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.2C
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• pp.91-99
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• 2003

In this paper, We analyze performance of ZFE MUD receiver in DSSS unidirectional wireless transceiver operating in 2.4㎓ ISM band and indoor environment. This system has the shortcomings that many burst error is occurred because of long term deep fade experienced by some user and impossibility of power control. Therefore, the solution to this problem is important because the performance of DS-CDMA system is guaranteed under, the perfect power control. MUD receive. which improves the performance of this system is not required to perform rigorous power control and is able to remove MAI using linear equalization. From the result of performance comparison, we show that ZFE MUD receiver is more adequate for this system than other receivers.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.404-406
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• 2016

Due to the localization process of offshore drilling system, ensuring safety has emerged as an important. Therefore, step by stem safety analysis about each development process of offshore drilling system is becoming compulsory. Hazard and operability analysis is a method that was successfully used for system safety analysis in industries such as chemical plants. Through this hazard and operability analysis study, to conduct step by step safety analysis accorsing to process, the study conducted hazard and operability analysis in Lp mud system, an area of offshore drilling system.

• Journal of the Korean Society for Marine Environment & Energy
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• v.20 no.2
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• pp.107-116
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• 2017

When drilling operation is being performed, many physical and chemical changes are occurred near wellbore. To handle various changes of well condition and keep drilling process safe, additives of bulk, such as bentonite for increasing density of drilling mud, barite for increasing viscosity of drilling mud, polymer for chemical control, or surfactant, are added into drilling mud through a mud shear mixer. Because the achievement of the required material property through mud mixing system is essential to stabilize drilling system, it is of importance to analyze multi-phase flow during mud mixing process, which is directly related to increase mixing performance of the system and guarantee the safety of the whole drilling system. In this study, a series of liquid-solid flow simulation based on a computational fluid dynamics (CFD) are performed with comparing to solid concentration in experiment by Gilles et al. [2004] to understand the characteristics of liquid-solid mixing in a mud shear mixer. And then, the simulation-based design of shear mixer are carried out to improve mixing performance in a mud handling system.

• Fisheries and Aquatic Sciences
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• v.20 no.12
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• pp.31.1-31.11
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• 2017

Background: Liver-expressed antimicrobial peptide-2 (LEAP-2) is an important component of innate immune system in teleosts. In order to understand isoform-specific involvement and regulation of LEAP-2 genes in mud loach (Misgurnus mizolepis, Cypriniformes), a commercially important food fish, this study was aimed to characterize gene structure and expression characteristics of two paralog LEAP-2 isoforms. Results: Mud loach LEAP-2 isoforms (LEAP-2A and LEAP-2B) showed conserved features in the core structure of mature peptides characterized by four Cys residues to form two disulfide bonds. The two paralog isoforms represented a tripartite genomic organization, known as a common structure of vertebrate LEAP-2 genes. Bioinformatic analysis predicted various transcription factor binding motifs in the 5'-flanking regions of mud loach LEAP-2 genes with regard to development and immune response. Mud loach LEAP-2A and LEAP-2B isoforms exhibited different tissue expression patterns and were developmentally regulated. Both isoforms are rapidly modulated toward upregulation during bacterial challenge in an isoform and/or tissue-dependent fashion. Conclusion: Both LEAP-2 isoforms play protective roles not only in embryonic and larval development but also in early immune response to bacterial invasion in mud loach. The regulation pattern of the two isoform genes under basal and stimulated conditions would be isoform-specific, suggestive of a certain degree of functional divergence between isoforms in innate immune system in this species.

• Journal of Ocean Engineering and Technology
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• v.35 no.2
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• pp.121-130
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• 2021

In this study, a computational fluid dynamics (CFD) simulation based on an Eulerian-Eulerian approach was used to evaluate the mixing performance of a mud agitator through the distribution of bulk particles. Firstly, the commercial CFD software Star-CCM+ was verified by performing numerical simulations of single-phase water mixing problems in an agitator with various turbulence models, and the simulation results were compared with an experiment. The standard model was selected as an appropriate turbulence model, and a grid convergence test was performed. Then, a simulation of the liquid-solid multi-phase mixing in an agitator was simulated with different multi-phase interaction models, and lift and drag models were selected. In the case of the lift model, the results were not significantly affected, but Syamlal and O'Brien's drag model showed more reasonable results with respect to the experiment. Finally, with the properly determined simulation conditions, a multi-phase flow simulation of a mud agitator was performed to predict the mixing time and spatial distribution of solid particles. The applicability of the CFD multi-phase simulation for the practical design of a mud agitator was confirmed.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.509-512
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• 2000

In this paper, the RBF-based multiuser detector (MUD) is proposed for a multirate DS/CDMA system. The performance of RBF-based MUD is compared with that of many suboptimal multiuser detectors in terms of bit error probability. From the simulation results, it is confirmed that the RBF-based multiuser detector outperforms decorrelating detector, and achieves near-optimum performance in several situations. The results in this paper can be applied to design of MUD fur a multirate DS/CDMA system.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.4_2
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• pp.617-626
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• 2020

The drilling mud is essentially used in oil and gas development. There are several roles of using the drilling mud, such as cleaning the bottomhole, cooling and lubricating the drill bit and string, transporting the cuttings to the surface, keeping and adjusting the wellbore pressure, and preventing the collapse of the wellbore. The fragments from rocks and micro-sized bubbles generated by the high pressure are mixed in the drilling mud. The systems to separate those mixtures and to keep the uniformly maintained quality of drilling mud are required. In this study, the simulation is conducted to verify the performance of the mud tank's agitation capacity. The primary role of the mud tank is the mixing of mud at the surface with controlling the mud condition. The container type is chosen as a mud tank pursuing efficient transport and better management of equipment. The single- and two-phase simulations about the agitation in the mud tank are performed to analyze and identify the inner flow behavior. The convergence of results is obtained for the vertical- and axis-direction velocity vector fields based on the grid-dependency tests. The mixing time analysis depending on the multiphase flow conditions indicates that the utilization of a two-stepped impeller with a smaller size provides less time for mixing. This study's results are expected to be utilized as the preliminary data to develop the mixing and integrating equipment of the onshore drilling mud system.