Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics最新文献_第3页

Elasto-Plastic Beam Afloat on Water Subjected to Waves 受波浪作用的水上弹塑性梁

Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics Pub Date : 2018-06-17 DOI: 10.1115/OMAE2018-78646

K. Iijima, Akira Tatsumi, M. Fujikubo

引用次数: 3

Undrained Uniaxial Capacities of Suction Bucket Foundations in Rows 排吸斗式基础不排水单轴承载力

Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics Pub Date : 2018-06-17 DOI: 10.1115/OMAE2018-77205

Zhong Xiao, Yumin Lu, Y. Liu

引用次数: 0

Benchmark of Erosion Criteria in a Deepwater Development 深水开发中侵蚀标准的基准

Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics Pub Date : 2018-06-17 DOI: 10.1115/OMAE2018-77477

S. Gómez-Álvarez, Fernando García Ruíz, D. Merino‐Garcia

{"title":"Benchmark of Erosion Criteria in a Deepwater Development","authors":"S. Gómez-Álvarez, Fernando García Ruíz, D. Merino‐Garcia","doi":"10.1115/OMAE2018-77477","DOIUrl":"https://doi.org/10.1115/OMAE2018-77477","url":null,"abstract":"Ultra-Deep water projects worldwide and particularly in Brazil are characterized by high capital investment costs. This fact generated the need to explore opportunities to improve project value, even though the project was still during visualization phase.\u0000 One of the identified opportunities was related to API 14E erosion standard application, as it is considered to be conservative for estimating the erosional limits in oil and gas applications. There are additional industry practices that are widely used in industry that provide more accurate estimations of erosional velocity limits. If these values are increased, there is an opportunity to enhance project value as it would allow a reduction of the required number of wells and production line / riser diameters. If the API erosional limit is considered in the project, the wells would produce at lower rate than reservoir potential, which would lead to an increase in the number of development wells. Based on the significant perforation cost of deepwater wells, the increase on this number would be reflected in the total development Capex, eroding the project value.\u0000 This paper describes the work performed in order to better understand the possible erosion phenomena in the production system due to the high fluid velocities in a gas condensate field and to determine the maximum allowable gas rate with different erosional models (API 14E and Tulsa SPPS).\u0000 The proposed methodology provides the opportunity to enhance project value by predicting erosional rate limits via SPPS, as the current applied standard was considered to be conservative in erosional rate prediction. If confirmed as feasible, significant cost reduction could be achieved in the project as the individual gas well production could be increased by the reduction of the number of wells; estimated well cost reduction is around 400 MMUSD per well, plus associated subsea production system.","PeriodicalId":106551,"journal":{"name":"Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117058585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental Study of Muddy Soil Inside Suction Bucket Foundation by Vacuum Electro-Osmosis 吸力桶基础内泥质土真空电渗透试验研究

Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics Pub Date : 2018-06-17 DOI: 10.1115/OMAE2018-77371

Zhang Pu-yang, Zhai Hanbo, Ding Hongyan, Le Conghuan

{"title":"Experimental Study of Muddy Soil Inside Suction Bucket Foundation by Vacuum Electro-Osmosis","authors":"Zhang Pu-yang, Zhai Hanbo, Ding Hongyan, Le Conghuan","doi":"10.1115/OMAE2018-77371","DOIUrl":"https://doi.org/10.1115/OMAE2018-77371","url":null,"abstract":"The composite bucket foundation of offshore wind power is a new type of foundation, which has been applied in practical engineering because of its advantages of large-scale prefabrication on land, integrated installation at sea and zero residual recovery. In order to overcome the shaft friction and tip resistance of the suction bucket, great passive suction is often applied during the penetration of the suction bucket. However, the large hydraulic gradient usually leads to seepage failure of the soil on beneath the top plate of the bucket foundation. As a result, the bearing capacity of the top plate of the bucket is often ignored. In this paper, the construction and construction process of composite bucket foundation are introduced, and series of model tests were carried out to reinforce the soil inside of the bucket foundation by the method of the vacuum electro-osmosis. The results show that the combined method of negative pressure and electro-osmosis can effectively improve the undrained shear strength of the soil and reduce the water content of the soil in the bucket foundation. Finally, the reinforcement effect of soil inside bucket foundation is analyzed according to reinforcement of the prototype construction.","PeriodicalId":106551,"journal":{"name":"Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116253373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Resonant Steady-State Sloshing in Upright Tanks: Effect of Three-Dimensional Excitations and Viscosity 直立储罐的共振稳态晃动:三维激励和粘度的影响

Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics Pub Date : 2018-06-17 DOI: 10.1115/OMAE2018-77534

A. Timokha, I. Raynovskyy

{"title":"Resonant Steady-State Sloshing in Upright Tanks: Effect of Three-Dimensional Excitations and Viscosity","authors":"A. Timokha, I. Raynovskyy","doi":"10.1115/OMAE2018-77534","DOIUrl":"https://doi.org/10.1115/OMAE2018-77534","url":null,"abstract":"Bearing in mind recent experimental and theoretical results showing that viscous damping can qualitatively affect resonant sloshing in clean tanks, the Narimanov-Moiseev multimodal sloshing theory for an upright circular container is revised to analytically analyze steady-state surface waves when the container performs a small-amplitude sway/roll/pitch/surge prescribed periodic motion with the forcing frequency close to the lowest natural sloshing frequency. The revised theory is applicable for the radius-scaled mean liquid depths h > 1 providing the secondary resonance phenomenon does not occur at the primary resonance zone. A focus is on how the damping influences the phase lag as well as on the amplitude response curves versus the forcing type, which can in the lowest-order approximation be treated as if the container translatory moves along an elliptic orbit in the horizontal plane. The analytical results are compared with existing experiments for longitudinal and circular orbital tank excitations. Whereas a good agreement is found for longitudinal excitations, a discrepancy is detected for the circular orbital forcing. The discrepancy may, most probably, be explained by the wave breaking and mean angular mass-transport (Ludwig Prandtl, 1949) phenomena. Occurrence of the Prandtl phenomenon makes inapplicable the existing analytical inviscid sloshing theories, even if they are modified to account for damping.","PeriodicalId":106551,"journal":{"name":"Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127835399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Simulation of Working Posture of Deepwater Gravity Sampling Device Using OpenFOAM 基于OpenFOAM的深水重力取样装置工作姿态模拟

Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics Pub Date : 2018-06-17 DOI: 10.1115/OMAE2018-77442

Zhe Ma, Da-wei Kong, Yin Wang, Nian-xin Ren, G. Zhai

引用次数: 0

Anchor Sharing in Sands: Centrifuge Modelling and Soil Element Testing to Characterise Multi-Directional Loadings 砂中的锚共享:离心机建模和土壤元素测试以表征多向载荷

Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics Pub Date : 2018-06-17 DOI: 10.1115/OMAE2018-77419

M. Herduin, C. Gaudin, L. Johanning

引用次数: 3

Modelling Turbulent Flow in Deformable Highly Porous Seabed and Structures 可变形高多孔海床和结构中的湍流模拟

Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics Pub Date : 2018-06-17 DOI: 10.1115/OMAE2018-77318

H. Elsafti, H. Oumeraci

引用次数: 0

Numerical Analysis of Second-Order Mean Wave Forces by a Stabilized Higher Order Boundary Element Method 用稳定高阶边界元法数值分析二阶平均波浪力

Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics Pub Date : 2018-06-17 DOI: 10.1115/OMAE2018-78350

{"title":"Numerical Analysis of Second-Order Mean Wave Forces by a Stabilized Higher Order Boundary Element Method","authors":"","doi":"10.1115/OMAE2018-78350","DOIUrl":"https://doi.org/10.1115/OMAE2018-78350","url":null,"abstract":"A stabilized Higher-Order Boundary Element Method (HOBEM) based on cubic shape functions is presented to solve the linear wave-structure interaction with the presence of steady or slowly varying velocities. The m-terms which involves second derivatives of local steady flow are difficult to calculate accurately on structure surfaces with high curvatures. They are also not integrable at the sharp corners. A formulation of the Boundary Value Problem (BVP) in a body-fixed coordinate system is thus adopted, which avoids the calculation of the m-terms. The use of body-fixed coordinate system also avoid the inconsistency in the traditional perturbation method when 2nd order slowly-vary motions are larger than the linear motions.\u0000 The stabilized numerical method presented in this paper is based on streamline integration and biased differencing scheme along the streamlines. The presence of convective terms in the kinematic and dynamic free surface conditions will lead to instable solution if the explicit method is used. Thus a fully implicit scheme is used in this paper for the time integration of kinematic and dynamic free surface conditions. In an implicit scheme, solution of an additional matrix equation is normally required due to the fact that the presence of convective terms are approximated using the variables at current time step rather than the previous time steps only. A method that avoids solving such matrix equation is presented in this paper, which will reduce the computational efforts in the implicit method. The methodology is applicable on unstructured meshes. It can also be used in general second order wave-structure interaction analysis with presence of steady or slowly-varying velocities.","PeriodicalId":106551,"journal":{"name":"Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133351622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Decommissioning of Offshore Monopiles, Occuring Problems and Alternative Solutions 近海单桩的退役、出现的问题和替代解决方案

Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics Pub Date : 2018-06-17 DOI: 10.1115/OMAE2018-78577

Nils Hinzmann, P. Stein, J. Gattermann

{"title":"Decommissioning of Offshore Monopiles, Occuring Problems and Alternative Solutions","authors":"Nils Hinzmann, P. Stein, J. Gattermann","doi":"10.1115/OMAE2018-78577","DOIUrl":"https://doi.org/10.1115/OMAE2018-78577","url":null,"abstract":"The German offshore wind industry has historically grown since the first offshore wind farm (OWF) “alpha ventus” was completed in 2010. Since the end of 2017 a total number of 18 OWF with a capacity of about 5 GW have been operating in the German Exclusive Economic Zone (EEZ) [1]. While the majority of the population and the industry focus on new projects, it appears the life cycle observation and especially the decommissioning phase remain largely unattended. This narrow view can lead to unexpected and expensive consequences in the future. The decommissioning of a complex structure as an offshore wind turbine (OWT) needs to be planned well in advance. There are numerous aspects that make the decommissioning a challenge, such as the federal regulations, the marine environment and the technical limitations of offshore operations.\u0000 This article gives an overview of the problematic matter of dealing with monopiles after the predicted lifetime, the geotechnical condition, analyses of the current decommissioning options and identification of issues in regards to the decommissioning method. Furthermore, other promising decommissioning methods for a complete removal of offshore monopiles, such as vibratory extraction, internal dredging, external jet drilling and the use of buoyancy force, are presented and compared concerning a possible combination. Some of the presented methods are highly experimental, others are commonly used in other industries.","PeriodicalId":106551,"journal":{"name":"Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132584316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6