bluuebunny/crossref_metadata_2025_split huggingface dataset:
Installation of the Residual Curvature Method for Reeled Pipe in Pipe
Authors: Barnes Ross , McRae Angus , Rai Jitender , Abdelmageed Gareer 
Published: October 2017

Current lateral buckling (LB) methodologies can be very expensive to implement and in some cases can have unsatisfactory trigger reliability. Imposing a designed Residual Curvature (RC) to provide an initiation point for lateral buckling, by appropriate modification to the straightener settings during reel-lay installation, is a relatively new and efficient method for LB initiation and has been applied in the field to single pipelines to date. The logical progression for this is to apply the RC methodology to the installation of reeled pipe in pipe (PiP).
PiP systems which are laid by reel-lay require detailed finite element analysis to determine vessel pipelay settings which ensure that the product is straightened as it leaves the vessel. In addition, imposing an RC section has further technical requirements over standard pipeline installation, i.e. meeting residual strain requirements over a specified length to deliver the required in-situ curvature needed for LB initiation. It is important to identify and optimise the solution to ensure that both installation and in-service requirements can be met and are practically achievable. Therefore, justification for use of the RC methodology for reeled PiP requires a portfolio of in-depth reeling and installation analyses to understand the application of this method for a complex reeled system, and how vessel and environmental influences may impact on the final solution.
To justify the implementation of the RC methodology for PiP, advanced non-linear FE analyses were used to assess vessel capabilities, the installation of PiP with RC and to determine the achievable in-situ RC for PiP. The effect and impact of reeling on the PiP is discussed in relation to both standard and RC pipelay. The paper discusses the technical challenges involved in the installation of an RC section for reeled PiP by presenting the methodologies employed in determining the achievable RC for PiP, the potential impact from environmental loading during installation and the resultant in-situ residual curvature that is expected.
Iceberg Impact Simulation on Offshore Structures
Authors: Cahay Marc , Roberts Brian A. , Pike Kenton , Béal Pierre-Antoine , Septseault Cyril , Mravak Zoran , Benoit Claudie 
Published: October 2017

In 2012 TechnipFMC, Cervval and Bureau Veritas initiated a common development program to offer a new tool for the design of offshore structures interacting with ice combining a variety of models and approaches.
This numerical tool called Ice-MAS (www.ice-mas.com) is using a multi-agent technology and has the possibility to combine in a common framework multiple phenomena from various natures and heterogeneous scales (i.e. drag, friction, ice-sheet bending failure, local crushing and rubble stack up). The current development phase consists of the determination of the forces generated by an iceberg during an impact on an offshore structure.
This paper will provide an overview of the latest Ice-MAS development. It will introduce the main functionalities of the simulation tool and the different options for modelling an offshore structure. It will then focus on the modelling approach used for an iceberg, the calculation of the different hydrodynamic coefficients and their variability according to the separation distance from the structure. The model used to compute the impact load will be detailed, including the local crushing behavior which is simulated by a pressure-area correlation.
Holistic Energy Mapping Methodology for Reduced Fuel Consumption and Emissions
Authors: Lim Serena , Pazouki Kayvan , Murphy Alan J. 
Published: October 2017

There are increasing concerns and regulations regarding the emission of pollutants from shipping. Therefore, regulations such as the Ship Energy Efficiency Management Plan (SEEMP) and Energy Efficiency Design Index (EEDI) have been made mandatory to cope with climate change concerns. To put these efforts into practice, the Energy Efficiency Operational Indicator (EEOI) was introduced in 2009 to account for the fuel consumption, distance travelled by the vessel and cargo mass. However, it is stated that these do not apply to ships that are not engaged in transport work such as research vessels and tugboats. These short sea shipping vessels have been neglected under current indexes and it is not possible for their properties to be quantified since current indices are for vessels carrying loads. The numbers of these specialised vessels are increasing in local waters, and are closer to coastal communities where concerns and impact from these pollutants would be more direct.
In the IMO greenhouse gas study, options for improving energy efficiency in terms of design includes the concept, design speed and capability, hull and superstructure, power and propulsion whilst the principle of energy efficiency in terms of operation includes fleet management, logistics and incentives, voyage optimisation and energy management. A reliable energy flow breakdown architecture and diagnostics for these smaller vessels is important and will contribute to an understanding of the energy production, distribution and consumption on-board. This feeds into the IMO plan to encourage energy management.
A systematic approach consisting of five distinct stages is recommended to accomplish a holistic approach for energy efficiency management. This includes understanding of energy flow breakdown architecture, vessel survey to understand operation and conduct, review existing sensors and new sensor installation, sensor communication and data processing, and finally data analysis. These stages are addressed in this paper to provide an overall understanding of a robust energy efficiency audit procedure and sensor matrix. This includes unifying the existing on-board sensors with the proposed new sensors for additional data collection where primary parameters are not readily available. Inferred secondary parameter calculations are also applied where direct data collection is not possible. This will allow information from the vessel to be transmitted to a common platform to enable detailed data analysis. The aim of this work is to improve energy management and monitoring, which leads to understanding and managing consumption of energy. A case study of this methodology has been carried out on the Princess Royal, a Newcastle University research vessel. Recommendations for further testing and optimisation of this methodology will be applied to tugboats and Offshore Supply Vessels (OSV).
Hydrodynamics and Capture Efficiency of Plastic Cleanup Booms: Part II — 2D Vertical Capture Efficiency and CFD Validation
Authors: Dommergues Bénédicte , Brambini Roberto , Mettler René , Abiza Zaki , Sainte-Rose Bruno 
Published: October 2017

To mitigate the growing impact of plastic pollution on marine ecosystems and global economy, The Ocean Cleanup (TOC) Foundation develops technologies to extract, prevent, and intercept plastic debris from coastal and oceanic environments. The core technology being optimized is the use of floating booms placed perpendicular to the main ocean plastic flow so it can concentrate plastic debris to a point where it can be extracted, shipped and processed in a cost-effective manner.
To investigate the capture efficiency of such a system, TOC conducted model scaled tests at the Dutch research institute MARIN. The objective of this paper is to present those tests along with the assessment of an hydrodynamic model and a CFD model to predict the dynamics of a rigid boom on one hand and the validation of this CFD model to predict the capture efficiency of such a boom.
Prevention of Alkali-Silica Reaction (ASR) in Light-Weight Wellbore Cement Comprising Silicate-Based Microspheres
Authors: Albers Dylan , Radonjic Mileva 
Published: October 2017

Drilling through low pressure formations, either offshore or through depleted formations, requires the use of low density fluids to prevent lost circulation and as well as to properly place cement during cementing applications. Achieving these densities in cements can be done through foaming the cement, increasing water content, or through the addition of silica based microspheres. Each of these methods have individual limitations, and in the case of silica based microspheres, their specific fallback is a chemical instability with the microsphere itself reacting with the cement pore fluid.
This chemical instability creates a hydrophilic gel that is expansive and creates fractures in the cement as it expands, which is more formally referred to as alkali-silica reactivity (ASR). Prevention of ASR involves the application of additives to the cement that acts as a sink for the alkalinity in which prevents the expansion of ASR. A specific application that this paper investigates for this prevention is the use of Lithium nitrate.
This study looks at the effects of a high alkalinity environment onto the microspheres by visualizing the reactions that are occurring using Scanning Electron Microscopy (SEM), and confirming the presence of ASR when silica based microspheres encounter a high pH environment. Then cement samples were created to compare the effects lithium nitrate has on cements created with silica based microspheres. SEM and micro indentation was conducted on these samples, which showed that lithium nitrate prevents reactions, but after 28-day hydration a loss of mechanical properties is present.
Development of a Simulator Training Platform for Fish Farm Operations
Authors: Holmen Ingunn Marie , Thorvaldsen Trine , Aarsæther Karl Gunnar 
Published: October 2017

The Norwegian aquaculture industry is accident prone compared to other industries and employees report a high number of near-accidents. Furthermore, escape of fish is a challenge for the industry. There is a potential for increased safety for both humans and fish if operators can practice operations in a safe environment. Existing simulators are not suited for this context.
This paper presents results from a research and development project aimed at developing a realistic simulator-based training platform for demanding fish farm operations. Three objectives guided the development process. First, a description of operations, aimed at identifying challenges and training needs, which formed the basis for selecting training scenarios well suited for aquaculture. Second, the development of mathematical models that could be used in the simulator were developed, and finally, a curriculum for training course modules to complete the platform. Platform thus points to the integration of the simulator and the practical and theoretical education of operators. In this article, the first and second part of the process are presented and discussed.
Experimental Investigation of Friction and Hydraulics in Circular and Non-Circular Wellbores With Oil Based Drilling Fluids
Authors: Taghipour Ali , Lund Bjørnar , Ytrehus Jan David 
Published: October 2017

Borehole hydraulics, hole cleaning and mechanical friction are important factors for well planning and drilling operations. Many studies aim to exploit and optimize the effect of different operational parameters. The effect of wellbore geometry on hole cleaning and mechanical friction has so far not received much attention. This paper presents results from experimental laboratory tests where hydraulics, hole cleaning and mechanical friction have been investigated for circular and non-circular wellbore geometries with a relevant oil-based field drilling fluid (OBM). The non-circular wellbore geometry was made by adding spiral grooves to the wellbore walls in order to investigate the effects on cuttings transport and mechanical friction. The study contributes to describe the function and ability of deliberately induced non-circular geometry in wellbores as means to achieve a more efficient drilling and well construction. Improving hole cleaning will improve drilling efficiency in general, and will in particular enable longer reach for ERD wells. Reduced mechanical friction may improve the drilling process and many operations during the completion phase.
The laboratory experiments were performed in an advanced flow loop setup reproducing field-relevant flow conditions. The flow loop consists of a 10 m long 4” inner diameter borehole made of concrete. A free whirling rotational string with 2” diameter provides a realistic down hole annular geometry. A field-relevant oil based drilling fluid (OBM) was circulated through the test section at different flow rates. To represent the effect of rate of penetration, synthetic drilling cuttings (quartz sand particles) were injected at different rates through the annulus in the horizontal test section. The test results show that borehole hydraulics and cutting transport properties are significantly improved in the non-circular wellbore relative to the circular wellbore. The effect of the mechanical friction is more complex, yet significantly different for the two geometries.
Parametric Sensitivity Study of Submarine Power Cable Design for Marine Renewable Energy Applications
Authors: Thies Philipp R. , Johanning Lars , Dobral Corentin 
Published: October 2017

An increasing use of submarine power cables is found in dynamic applications such as floating wind, floating wave and tidal generation technologies. These applications substantially differ from common applications, such as floating oil and gas installations in that they are more dynamic. Power cables that cross the water column, so-called umbilicals will be exposed to considerable extreme and fatigue loads mainly induced by the motion of the device, incident waves and tidal current. The actual loading regimes of dynamic submarine power cables in operation are not well understood for marine renewable energy (MRE) applications due to a lack of field experience. The cable design has to consider a combination of cable geometry, hydrodynamic parameters, suitable layout configuration, suitable ancillary systems (e.g. bend stiffeners) in relation to the environmental site conditions.
This paper evaluates the influence of the environmental conditions and the cable design parameters on the mechanical loads and potential failure modes of a dynamic submarine power cable attached to a dynamic floating body in form of a generic point absorber. One notable result is the large effect of the tidal direction, even in relatively moderate flow conditions. The full range of tidal flow conditions should be considered in the power cable design to ensure that the cable MBR is not exceeded in any conditions. The shown configurations also give some insight into the possible variations of the geometric cable configuration. A well balanced S-curve shape yields some of the best results and achieves a good load distribution along the cable and the transition points, whilst avoiding cable compression. The design challenge for the cable configuration is to maintain the S-shape for as many environmental and device response modes as possible in order to achieve high reliability. This paper will be useful for cable, device and site developers of floating MRE to inform the selection of the most suitable cable design.
Physics-Based Gearbox Failure Model for Multi-MW Offshore Wind Turbines
Authors: Sepulveda Marco , Shek Jonathan , Thies Philipp R. , Oterkus Erkan , Davies Peter , Spring Mark 
Published: October 2017

This study proposes an analytical methodology to assess the risk to the operation of an offshore wind turbine in order to identify critical assemblies. The gearbox is one of the critical assemblies regarding maintenance costs and downtime. Failure investigation shows that the high speed shaft bearings are one of the gearbox components with a higher probability of fatigue damage. A physics-based model is developed to calculate the accumulated damage and to estimate the remaining useful life. The model is created for a 3 stage gearbox with two planetary and one parallel helical gear.
This paper summarises the methodology and results of a damage accumulation calculation under a load spectrum derived from 1 year of SCADA data. The final results are consistent with the damage levels found in the failure investigation.
Revision of DNV GL Design Standard for Floating Wind Turbine Structures
Authors: Hopstad Anne Lene Haukanes , Ronold Knut O. , Argyriadis Kimon 
Published: October 2017

The first edition of the DNV Offshore Standard “Design of Floating Wind Turbine Structures”, DNV-OS-J103, was published in June 2013. The standard represented a condensation of all relevant requirements for floaters in existing DNV standards for the offshore oil and gas industry which were considered relevant also for offshore floating structures for support of wind turbines, supplemented by necessary adaptation to the wind turbine application.
As part of the harmonization of the DNV GL codes for the wind turbine industry after the merger between Det Norske Veritas (DNV) and Germanischer Lloyd (GL) in the autumn of 2013, DNV GL currently plans to publish a revision of DNV-OS-J103 in 2017, to become identified as DNVGL-ST-0119.
The new revision is intended to reflect the experience gained since 2013 as well as the current trends within the industry.
Frequency Domain Analysis of the Interactions Between Multiple Ships With Nonzero Speed in Waves or Current-Wave Interactions
Authors: Liu Yujie , Falzarano Jeffrey M. 
Published: October 2017

We study the multi-body problems with a nonzero speed or with current-wave interactions using the Green function method. The two problems are equivalent when the current is along the longitudinal direction of the ship.
The formulations of a single ship for the zero-speed and nonzero-speed cases are derived. The concepts, the motivations and the assumptions are explained. We also provide the derivations of the added mass and damping for the asymmetric ship profile. Then we extend the conclusions to the multiple ships and formulate the multi-body problems. The in-house program MDL Multi DYN is validated through the study of two Wigley hulls with zero speed in waves. After that, the results for two moving Wigley hulls are generated. The two ships are assumed to advance in parallel at the same speed. Finally, the effects of the separation distances and the different speeds are discussed.
Numerical Simulation of Motion of Rotating Drill Pipe due to Magnus Effect in Riserless Drilling
Authors: Inoue Tomoya , Suzuki Hiroyoshi , Tar Thaw , Senga Hidetaka , Wada Kazuyasu , Matsuo Miki Y. 
Published: October 2017

During riserless drilling operations, which are carried out in some scientific drillings and in the initial stages of all drilling operations in oil and gas exploration, a lifting force is generated in addition to a drag forces in ocean current environment owing to the ocean current and the rotation of the drill pipe. This is called the Magnus effect, and it is a critical phenomenon during such operations.
First, the lifting and drag forces are calculated using the computational fluid dynamic (CFD), and the lift and drag coefficients are calculated for several rotational velocities of the drill pipe and the velocities of the ocean current. It can be observed through the calculations that the lifting force increases as the rotational velocity of the drill pipe increases, and it reaches a level of approximately several times that of the drag force. The force reaches such a considerably high magnitude that it can induce the motions of the drill pipe, resulting in the generation of a high bending moment.
An analytical model of a drill pipe has been established by applying an absolute nodal coordinate formulation (ANCF), which can express a relatively flexible and long pipe, such as a drill pipe. ANCF is a finite element method, and was basically developed to analyze deformable linear objects such as the cable. With ANCF, the absolute slopes of elements are defined based on the absolute nodal coordinate. Finally, the drill pipe motions are simulated using the established model by applying the results of CFD simulations for sample cases and referencing the operation of the Chikyu.
A Numerical Model for Submarine Pipelines With Concrete Coating
Authors: Nguyen Ngoc , Fyrileiv Olav , Chia Chor Yew 
Published: October 2017

This paper presents a numerical model that is used to estimate the structural response of a submarine pipeline with concrete weight coating subjected to loadings commonly encountered in pipeline installation and operation phases. Findings from parametric studies performed with the numerical model are used to widen the applicable range of the simplified concrete crushing criterion in DNV-OS-F101 (2013) and formulate a rational approach for the design of pipeline concrete weight coating under typical installation and operation conditions. The rational design approach will allow for potential selection from a wider range of installation vessels and relaxation of the installation weather window criterion. The design method also provides insights into the strain concentration in the field joint at different strain levels, which is used to assess the field joint welding integrity for pipeline in free spans and in high strain conditions.
The numerical model considers nonlinearities in steel and concrete material stress and strain, as well as complex adhesive behaviour of the anti-corrosion coating. Good agreement is obtained between the numerical results and existing experimental data for all the sections along the pipeline model where comparisons are made on moment–strain global behaviour, sliding from the concrete coating, hot spot strain near the field joint and concrete strain.
The numerical program is performed within the scope of Phase 1 of the joint industry project called “Design of concrete coating for submarine pipelines”. Laboratory tests to check and improve the numerical model are planned for Phase 2.
Development of Fatigue Design Standards for Marine Structures
Authors: Lotsberg Inge 
Published: October 2017

Fatigue design standards for offshore structures became needed with development of offshore structures in harsh environments like the North Sea during the 1970s. The Ultimate Limit State had earlier been the most significant design requirement for similar platforms in the Mexican Gulf being less utilized with respect fatigue.
The need for fatigue design of ship structures became increased as more high strength steel was being used in these structures during the 1970s. The analysis method for long term loading and assessment of fatigue capacity has been improved over the years and this has also resulted in need for new and revised design standards.
New types of structures and structural components have been developed like tension leg platforms and support structures for wind turbines. These structures are subjected to significant dynamic loading such that fatigue design becomes the main issue and relevant fatigue design standards are needed.
Fatigue assessment of fixed offshore structures in the North Sea has been standard practice since the 1970s. Fatigue of floating platforms became a requirement after the accident with the Alexander Kielland platform in 1980. Later new types of structures have been installed in the North Sea such as tension leg platforms and floating production ships where fatigue has been an important part of the design. A further challenge with respect to fatigue came with the development of support structures for wind turbines to be installed in the sea.
This paper gives an overview of the development of fatigue design standards for marine structures over the last 40 years. This includes the significance of refined calculation of long term stress range distribution, calculation of hot spot stress, size effect and effect of mean stress effect on fatigue design of ship structures.