• 한국산업융합학회 논문집
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• 제26권5호
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• pp.895-905
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• 2023

Mud tanks used for storing and supplying mud in mud supply systems are essential to secure structural stability according to the mud loads inside the tank. In terms of structural stability of the mud tank can be ensured by increasing the thickness of the structure. However, increasing the thickness may cause a problem of increasing production costs. In addition, this increases the weight of the tank, which can cause problems with the trailer loading weight limitation during transportation. To satisfy both these problems and structural stability, the mud tank should be optimally designed. Therefore, this study conducted an optimum design in consideration of the load of the mud tank through the structural analysis and response surface optimization method in ANSYS.

• 한국산업융합학회 논문집
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• 제23권4_2호
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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.

• 대한기계학회논문집 C: 기술과 교육
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• 제4권2호
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• pp.85-92
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• 2016

LNG선의 발라스트 탱크에 해수를 유입할 때 해수에 부유하고 있는 해저면의 머드 입자가 탱크 안으로 유입되고 탱크내에 침전되는 문제가 발생한다. 탱크에서 해수를 배출 할 때에 침전된 머드를 함께 제거할 수 있도록 발라스트 탱크 내에 머드 플러싱 시스템을 적용하였다. 본 연구에서는 플러싱 시스템의 머드 제거 효과를 평가하기 위해 입자 크기 분석기를 통해 머드의 입자 크기를 측정 하였으며, 입자 크기와 전단 응력의 관계를 바탕으로 수치해석을 통해 머드의 부유 성능을 평가하였다. 탱크내 머드 플러싱 배관 시스템을 최적화하여 탱크내 머드 부유 성능을 극대화하였다.

• 한국해양공학회지
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• 제28권2호
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• pp.111-118
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• 2014

In drilling process of oil wells, the drilling fluid such as mud keeps the drill bit cool and clean during drilling, with suspending drill cuttings and lubricating a drill bit. In this paper, a commercial CFD package(ANSYS Fluent 15.0) was used to solve the hydrodynamic force and evaluate mud mixing time in the mud mixing tank on offshore drilling platforms. Prediction of power consumption in co-rotating and counter-rotating models has been compared with results of Nagata's correlation equation. This research shows the hydrodynamic effect inside the two phase mud mixing tank according to rotating directions(co-rotating and counter-rotating). These results, we can conclude that the co-rotating direction of the two shafts with mixing blade in the mud mixing tank can be a preferable in power consumption and mixing time reduction.

• 한국유체기계학회 논문집
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• 제17권6호
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• pp.29-37
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• 2014

Non-Newtonian fluid mechanics takes charge of an important role in the oil industries. Especially in the oil well drilling process, the drilling fluid such as mud keeps the drill bit cool and clean during drilling, with suspending drill cuttings and lubricating a drill bit. The purpose of this study is to examine the effect of fluid mud rheological properties to predict different characteristics of non-Newtonian fluid in the mud mixing tank on offshore drilling platforms. In this paper, ANSYS fluent package was used for the simulation to solve the hydrodynamic force and to evaluate mud mixing time. Prediction of the power consumption and the pumping effectiveness has been presented with different operating fluid models as Newtonian and non-Newtonian fluid. The comparison between Newtonain mud model and non-Newtonian mud model is confirmed by the CFD simulation method of drilling mud mixing tank. The results present useful information for the design of the drilling mud mixing tanks and provide some guidance on the use of CFD tool for such non-Newtonian fluid flow.

• 한국해양환경ㆍ에너지학회지
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• 제8권3호
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• pp.158-163
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• 2005

본 연구의 목적은 적조구제에 사용하기 위해 개발된 Nano-S를 해양에 이용함에 있어 Nano-S가 해양환경에 미치는 영향을 조사하는데 있다. 실험은 용적이 180L인 원형의 유수식 수조에서 이루어 졌다. 각각의 수조에는 $14{\pm}1cm$의 니질의 퇴적물을 수조의 바닥에 깔고 해수가 수조를 흘러 넘치도록 채웠다. 수조에 공급되는 해수의 양은 ]밀 1회 환수 되도록 하였으며, 일주일동안 수조를 안정화 시켰다. 다섯 개의 수조에 Nano-S 및 적토를 각각 0 kg(대조구), 1 kg(수조 A), 2 kg(수조 B), 5 kg(수조 C) and 10 kg(수조 D)채웠으며 이러한 양은 저질의 단위면적($m^2$)당 각각 0 kg(대조구), 2.75 kg(수조 A), 5.51 kg(수조 B), 13.77 kg(수조 C) and 27.55 kg(수조 D)을 차지하였다. 실험은 총 30일 동안 진행했으며, 수질과 저질의 시료는 Nano-S 및 적토의 투입 1시간 전과투입 후 1시간, 3시간, 6시간, 12시간후와 1일, 3일, 5일, 7일, 10일, 15일, 30일후에 각각 채취하여 Nano-S의 투입전후의 수질과 저질의 변동을 분석하였다.

• 한국해양공학회지
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• 제33권1호
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• pp.42-49
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• 2019

Drilling mud was used once in the step of separating the gas and powder they were transported to a surge tank. At that time, the fine powder, such as dust that is not separated from the gas, is included in the gas that was separated from the mud. The fine particles of the powder are collected to increase the density of the powder and prevent air pollution. To remove particles from air or another gas, a cyclone-type separator generally can be used with the principles of vortex separation without using a filter system. In this study, we conducted numerical simulations of air-particle flow consisting of two components in a cyclone separator in a mud handling system to investigate the characteristics of turbulent vortical flow and to evaluate the collection efficiency using the commercial software, STAR-CCM+. First, the single-phase air flow was simulated and validated through the comparison with experiments (Boysan et al., 1983) and other CFD simulation results (Slack et al., 2000). Then, based on one-way coupling simulation for air and powder particles, the multi-phase flow was simulated, and the collection efficiency for various sizes of particles was compared with the experimental and theoretical results.

• 한국농공학회논문집
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• 제55권1호
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• pp.49-57
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• 2013

The present study was conducted to investigate phosphate removal from aqueous solution using industrial wastes, red mud (RM), acid treated red mud (ATRM) and converter furnace steel slag (CFSS). The chemical composition of adsorbents was analyzed using X-ray fluorescence (XRF). Batch experiments and elution experiments using water tank were performed to examine environmental factors that influences on phosphate removal. Kinetic sorption data of RM, ATRM, and CFSS were described well by the pseudo second-order kinetic sorption model, and equilibrium sorption data of all adsorbents obeyed Freundlich isotherm model. The adsorption capacities of adsorbents followed order: ATRM (7.06 mg/g)>RM (4.34 mg/g)>CFSS (1.88 mg/g). Increasing pH from 3 to 11, the amount of adsorbed phosphate on all RM, ATRM, and CFSS were decreased. The presence of sulfate and carbonate decreased the phosphate removal of RM and ATRM but did not influence on the performance of CFSS. The phosphate removal of RM, ATRM, and CFSS was greater in seawater than deionized water, resulting from the presence of cations in seawater. The water tank elution experiments showed that RM capping blocked the elution of phosphate effectively. It was concluded that the adsorbents can be successfully used for the removal of the phosphate from the aqueous solutions.

• 한국음향학회지
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• 제22권1호
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• pp.78-87
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• 2003

고주파 (126-㎑) 음향 신호를 이용하여 퇴적층의 구성 매질 및 표면 형태에 따른 산란 신호 변화를 측정하였다. 퇴적층은 구성 매질에 따라 사니질 (sandy mud), 사질 (sand), 자갈 (gravel)의 세가지 경우와 이를 혼합한 경우로 하였으며, 표층 연흔 (ripple) 형태에 따라 연흔과 음파 진행방향이 직각을 이루는 경우 및 평행한 경우를 모의하였다. 평면입사각 변화 및 연흔 구성 형태에 따른 후방산란 강도는 평면입사각에 비례하여 증가하였으며, 연흔 형성 방향과 음파 진행 방향이 이루는 각이 작을수록 삼차원적인 측방산란이 강하게 나타났다. 연흔과 음파가 이루는 각이 증가할수록 후방산란은 증가하였으며, 지음향적 요소 외에도 연흔 형성과 방향에 음파 산란이 강하게 의존함을 알 수 있었다.

• 한국양식학회지
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• 제16권1호
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• pp.44-50
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• 2003

가시파래의 자연 서식지에서 자연채묘 방법과 실내에서 포자방출에 의한 인공종묘생산 기술을 개발하고, 양성시험에 의한 완전한 양식방법을 개발하여 대량생산 가능성을 조사하였다. 가시파래 자연채묘는 자연 서식지의 사니질로 조성된 해역이 적합하였으며, 하계의 착생밀도는 채묘틀이 지면에서 20cm 높이에 시설하는 것이 높았고, 추계에는 40cm 높이에 시설하는 것이 효과적이었다. 가시파래 인공종묘 생산은 성숙한 모조를 12~24시간 음건하여 포자를 방출하고, 포자액이 들어있는 수조에 채묘망을 넣고 24시간 암흑처리하면 포자 착생률이 높게 나타났다. 가시파래 양성은 수심이 낮고 저질이 니질 또는 사니질로 조성된 해역은 지주식으로 시설하며, 수심이 깊고 유속이 빠른 해역은 부류식으로 시설하는 것이 좋았다. 양성장소는 영양염이 풍부하고 파랑에 의한 엽체의 탈락과 시설물 파손이 적은 해역이 양호하였으며, 광합성률을 높이기 위하여 표층노출식으로 시설하는 것이 생산량이 많았다.