bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling Transient Circulating Mud Temperature in the Event of Lost Circulation and its Application in Locating Loss Zones
Authors: Chen Yuanhang , Yu Mengjiao , Miska Stefan , Ozbayoglu Evren , Kang Yongfeng , Zhou Shaohua , Al-Khanferi Nasser 
Published: September 2014

Lost circulation is one of the most persistent and costly drilling problems that drilling engineers have been struggling with for decades. The main reason why some of the remedial procedures are not working as planned is the lack of information, such as the location of the loss zone. The pinpointing of the zone of loss will allow the treatment to be applied directly to the point of loss rather than to the entire open hole.
This paper presents an approach to predict the location of loss zone from the transient mud circulation temperature profile altered by the mud loss. A numerical model in estimating the transient mud circulating temperature profile during a lost circulation event is developed. The temperature profile in both the flow conduits (drillpipe and annulus) are modeled using mass and energy balance. The flow rate of drilling mud decreases in the annulus above the loss zone as part of the fluids lost into the fractures, which in turn alters the heat transfer between the drillpipe, annulus, and formation. The wellbore is divided into two multiple sections, which account for single multiple loss circulation zones. Rigorous heat transfer in the formation is included. Case studies are performed and numerical solution results are presented and analyzed. According to the results, temperature alterations induced by mud loss include: 1) Declines in both bottom-hole temperature (BHT) and mud return temperature over time, and 2) Discontinuity in the first order derivative of annulus temperature with respect to depth at the location of loss zone; meanwhile, the temperature alterations are mainly controlled by the mud loss rate and location of loss. By matching the simulated results with the distributed temperature measurements at different times, the depth of the loss zone can be identified. This piece of information is important for the spotting of LCM (lost circulation material) pills, the optimization of overbalance squeezing pressure, as well as the consideration of setting the cement plug or additional casing.
Analysis of Sea Shock Encountered by a Ship in North East Japan
Authors: Shiotani Shigeaki , Sasa Kenji 
Published: September 2014

In general, earthquake motion experienced by a navigable vessel is called a sea shock (or seaquake). Sea shock is assumed that the vertical ground motion of the sea floor propagates as a compressional (longitudinal) wave in water.
Seaquakes are sudden, unexpected phenomena that are induced by undersea earthquakes. There are almost no examples of their systematic measurement and the phenomenon of seaquakes is said to not be thoroughly understood.
The effect of seaquakes was studied theoretically during the 1990s, during research on the wave response of structures for the construction of VLFS. However, There are a few experimental studies on the effect of seaquakes on floating bodies because of the problem of reproducibility.
We measured ship motion caused by sea shocks by examining seabed oscillation. Such measurements provided very valuable data. The conclusions obtained in the present study are that ship motion caused by sea shocks has high-frequency oscillation. In particular, the acceleration in the z direction is remarkable.
Upheaval Creep of Rock Dumped Flexible Flowline
Authors: Zhengmao Yang , Norland Kristian , Brown Neil , Karunakaran Daniel 
Published: September 2014

For the protection from dropped object/fishing trawl impact, flexible flowlines are normally trenched or rock-dumped. And hence, upheaval buckling and lateral buckling may be promoted by the elevated temperatures and high pressures. Due to the unique properties of un-bonded flexible flowline, the flexible flowline may creep in the trench or rock berm when it is subjected to cyclic pressure and temperature changes due to start-up and shut-down of flowline in service.
In this paper, a finite element analysis model for the global buckling and upheaval creep of flexible flowline is proposed. In this model the effect of bending stiffness hysteresis are considered in addition to the temperature and pressure changes in each start-up/ shut-down cycle. A case study of a 10″ water injection flowline is performed by using finite element analysis software package ANSYS. The nonlinear general beam section is used to simulate the specific flexible pipe behavior, nonlinear bending behavior but linear axial behavior.
Development of a Prediction Formula for Ship Resistance in Level Ice
Authors: Cho Seong-Rak , Jeong Seong-Yeop , Lee Sungsu , Kang Kook-Jin 
Published: September 2014

Icebreakers are mainly classified according to the breakable thickness of level ice, although they differ slightly according to each ship’s classification and by country. The breaking performance in level ice is a priority factor for icebreakers and is directly linked to ships’ safety and survival in extreme environments. In addition, some large cargo vessels with an icebreaking capability have recently been built, and various types of commercial icebreakers will appear when the Northern Sea Route is activated in the future.
In this paper, previous studies on ice resistance are reviewed and analyzed by arranging the merits and demerits of each study. We developed a new prediction equation of ice resistance by analyzing the resistance components, such as the breaking, buoyancy, and clearing resistance, and using dimensional and regression analyses on ice model tests. This procedure could be applied to large merchant vessels and is intended to contribute to the prediction of icebreakers’ ice performance.
Extreme Wave Condition at Doggerbank
Authors: Engebretsen Espen , Haver Sverre K. , Myrhaug Dag 
Published: September 2014

In design of offshore wind turbines, extreme wave conditions are of interest. Usually, the design wave condition is taken as the sea state corresponding to an annual exceedance probability of 2·10−2, i.e. a return period of 50 years. A possible location for a future wind farm, consisting of bottom fixed wind turbines, is the Doggerbank area, see Figure 1. The water depth in this area varies from about 60m in the north to about 20m in the south.
The hindcast database NORA10 provides sea state characteristics from 1957 to present over a domain covering Doggerbank. Regarding the deeper areas just north of Doggerbank, this hindcast model is found to be of good quality. Larger uncertainties are associated with the hindcast results as we approach shallower water further south. The purpose of the present study is to compare sea state evolution over Doggerbank as reflected by NORA10 with the results of commonly used shallow water hindcast model SWAN.
The adequacy of the default parameters of SWAN for reflecting changes in wave conditions over a sloping bottom is investigated by comparison with model test results.
Extreme wave conditions for two locations 102.5km apart in a north–south direction are established using NORA10. This is done using both an all sea states approach and a peak over threshold approach. Assuming the extremes for the northern position to represent good estimates, the wave evolution southwards is analyzed using SWAN. The extreme condition obtained from NORA10 in the northern position is used as input to SWAN and the results from the two hindcast models are compared in the southern position. SWAN seems to suggest a somewhat faster decay over Doggerbank compared to NORA10.
Effect of Reeling Simulation on the Mechanical Properties of New Duplex Stainless Steel for Line Pipe
Authors: Shitamoto Hidenori , Sagara Masayuki , Amaya Hisashi , Hisamune Nobuyuki , Motoya Daisuke , Watatani Yuuki 
Published: September 2014

Corrosion resistant alloys (CRAs) such as martensitic and duplex stainless steels (DSS) are used as a flow line material in corrosive wet gas environments (i.e., carbon dioxide and hydrogen sulfide environments). A new DSS which consists of 25mass%Cr - 5mass%Ni - 1mass%Mo - 2.5mass%Cu has been developed for line pipe usage in slightly sour environments.
There are several methods currently being used to install offshore oil and gas pipelines. The reel-lay process is fast and one of the most effective offshore pipeline installation methods for seamless, ERW, and UOE line pipes with outside diameters of 18 inches or less. In the case of the reel-laying method, line pipes are subjected to plastic deformation multiplication during reel-laying. Thus, it is important to understand the change of the mechanical properties of line pipes before and after reel-laying.
In this study, full-scale reeling (FSR) simulations and small-scale reeling (SSR) simulations were performed to investigate the effect of cyclic deformation on the mechanical properties of the new DSS for line pipe. Furthermore, investigation of the most susceptible temperature range to cracking and sulfide stress cracking (SSC) tests were performed in slightly sour conditions.
Experimental Comparison of Tensile Armor Wires Using Strain Gages and Fiber Bragg Grating Techniques
Authors: Vargas Felipe Arêas , Lopes Diogo Garcia , Kenedi Paulo Pedro , Clevelario Judimar , de Souza Pires Fabio 
Published: September 2014

Flexible pipes are being installed and operated in more marginal and challenging offshore conditions related to deep-water environments. Especially important is the accurate assessment of the remaining life of a flexible riser so operators can avoid costly premature change outs. So, emerging inspection and monitoring technologies are being several developed to achieve a comprehensive flexible pipes integrity approach.
For unbonded flexible pipes, the primary challenges include fatigue life, collapse, axial compression loading of the tensile armor wires and end fitting development.
This paper is related to end fitting development area, due to necessary folding/unfolding process on the tensile armor wires during pipe assembling. This mechanical forming generates high levels of plastic strain on the wires, which may therefore reduce the fatigue life of the flexible pipe in the field.
This paper presents an analysis of the high strain level involved in the folding and unfolding process along tensile armour wire, using the strain gages and fiber Bragg grating techniques.
Besides that, this paper describes a comparison analysis, which correlates the performance of both methods to assess high strain levels.
Application of Combination of Local Domain Free Discretization and Immersed Boundary Method (LDFD-IBM) to Numerical Simulation of 3D Flows Over a Circular Cylinder
Authors: Wu Yanling , Shu Chang , Gullman-Strand Johan 
Published: September 2014

In this paper, the recent developed Local Domain Free Discretization method combined with Immersed Boundary Method (called LDFD-IBM) is extended from two-dimensional version to three-dimensional version. LDFD-IBM is a new member in the family of Cartesian mesh methods. The advantages of LDFD-IBM over other Cartesian mesh solvers includes: no cutting cell, easy to adaptive mesh refinement, easy to implement for moving boundary problems, truly second order accuracy over whole domain, no flow penetration into the solid wall.
LDFD-IBM three-dimensional solver is then used to simulate three-dimensional flow past a circular cylinder. Both oblique mode and parallel mode of vortex shedding of the cylinder in three-dimensional configuration are reproduced according to different end-conditions. Oblique shedding is one of the important three-dimensional features that could influence the amplitude, frequency and phase of the flow-induced forces.
Modelling Issues for Nonlinear Time History Analysis of Offshore Platforms Subjected to Strong Ground Motions
Authors: Nezamian Abe , Morgan Patrick M. 
Published: September 2014

The response of a platform subjected to a strong ground motion is highly affected by the method of modelling, and special attention should be paid to such advanced analysis.
While the potential of dynamic inelastic analysis and performance based design of offshore platforms is recognised in earthquake design and assessment, they have inherent shortcomings. This paper discusses the critical issues and their effects on the obtained results in the application of inelastic dynamic analysis. Areas of possible developments that would render the method more applicable to the prediction of dynamic response, and new developments towards a fully adaptive performance based design are explored. These developments lead to dynamic analysis results that are closer than ever to the true inelastic time-history behavior of the structures.
It is concluded that there is great scope for improvements of this powerful technique that would increase confidence in its employment, and encourage its use during design as the primary tool for reliability assessment under seismic loads. The results from a sample project indicated that inelastic time history seismic analysis provides a more realistic assessment of structural behavior and strongly recommended to be implemented for the design and reliability assessment of the fixed offshore structure under extreme seismic event.
Risk-Based Approach for the Development of Guidelines and Standards on Combined Marine Renewable Energy Platforms
Authors: Macadré Laura-Mae , O’Sullivan Keith , Breuillard Antoine , le Diraison Stéphane 
Published: September 2014

The combination of Marine Renewable Energy (MRE) technologies such as wave or current devices with offshore wind, a more mature technology, could enable pooling of R&D efforts and reducing costs (grid connection, moorings, maintenance activities…). Moreover, the different characteristics of the wind, wave and current resources could be complementary and provide a smoothing effect on the power production. Therefore, the EU FP7 project -MARINA Platform- aims at studying concepts of combined platforms integrating different types of MRE devices.
Many challenges are induced by these innovative platforms and guidelines and standards will be required to ensure safety, reliability and quality. However, as the concepts are only at the development stage, no standards have been written for these combined platforms so far.
This paper presents a new approach proposed by Bureau Veritas within the scope of the MARINA project for the development of guidelines and standards dedicated to combined MRE platforms. Existing literature on standards about MRE and related sectors, like shipping, wind energy and offshore oil & gas, forms a good basis to be exploited. In addition, risk assessment and qualification of new technology might be considered as a complement to standards to support the design of novel offshore concepts. Therefore, the presented methodology combines the use of existing standards from MRE and related sectors with a risk-based approach for the most innovative and unknown parts of the platform. A global risk assessment is performed in parallel for a whole review of the system.
Development of an Approach Towards Mission-Based Design of Arctic Maritime Transport Systems
Authors: Bergström Martin , Ehlers Sören , Erikstad Stein Ove , Erceg Sandro , Bambulyak Alexei 
Published: September 2014

This paper describes an approach that utilizes a discrete event simulation tool and ice data from a numerical ice prediction model to enable mission-based design of arctic maritime transport systems consisting of a single or multiple arctic cargo ships.
For a specific vessel design and route, the developed approach makes it possible to simulate how the transit time varies over time due to both varying ice conditions and stochastic factors such as the weather. Thus, for a given transport scenario (route, transport demand, and period of time), the approach can be used to determine a suitable vessel capacity, propulsion power, and ice class. When necessary, the approach can be used to analyze and design more complex transport system consisting of multiple vessels and routes.
A case study is carried out to demonstrate how the approach could be applied in practice. The outcome of the case study indicates that the approach generates realistic figures, and that it is flexible enough to make it possible to vary the number of included parameters and variables as needed.
The Development of Meteorological and Oceanographic Data Collection and Recording System Operating on Training Ship
Authors: Fujii Michio , Hayashi Mitsuru , Urakami Misako , Wakabayashi Nobukazu 
Published: September 2014

The observation at sea for marine meteorology is achieved by weather reports from merchant ship’s crew every 3 or 6 hours, mainly. However, the number of available observation data is insufficient for weather forecasting and marine environmental simulation, compared with landside. Nowadays, the special data collection function is required if the automatic observation data collection system is installed on ship. But, it is difficult to install special equipment onto general merchant ship. Therefore, we develop a prototype marine observation system, which can be installed various types of ships easily without any special data collection function for improving data collection source and/or period of the observation at sea.
In this paper, a) the configuration of high reliability and durability marine observation system by using general-purpose PC and general meteorological / oceanographic sensors, b) outlook of utilizing the data, which collected by this system, are described.
Impact Resistance Cryogenic Bunker Fuel Tanks
Authors: Voormeeren Lars O. , Atli-Veltin Bilim , Vredeveldt Alex W. 
Published: September 2014

The increasing use of liquefied natural gas (LNG) as bunker fuel in ships, calls for an elaborate study regarding the risks involved. One particular issue is the vulnerability of cryogenic LNG storage tanks with respect to impact loadings, such as ship collisions and dropped objects. This requires an understanding of the impact resistance of the storage tanks and the actual loads to be expected. No substantial literature exists on the actual energy absorbing capacity (crashworthiness) of cryogenic tanks. Main issues are material properties under cryogenic/ moderate strain rate conditions and failure mechanisms associated with large deformation - fluid structure interaction, in particular the liquid-full condition.
This paper reports material properties of stainless steel 304 at both ambient and cryogenic conditions. Also the effect of strain rate is addressed. Moreover, it describes and compares two approaches of predicting the effect of the ‘liquid-full’ condition on the impact resistance of LNG storage tanks. The first approach follows a multi-material Arbitrary-Lagrangian-Eulerian (ALE) formulation, whereas the second approach captures the fluid-structure interaction through an analytical loading subroutine, calculating the internal pressure as a function of tank volume decrease. Results of impact experiments on partially liquid-filled small-scale storage tanks are presented. The calculation methods have been validated against the experimental results. The results of the validation show that the crashworthiness of stainless steel (cryogenic) storage tanks can be well predicted through both the ALE and the analytical formulation.
On Determination of Acceptable Safety Class in Design of Pipe-In-Pipe (PIP) Systems
Authors: Manouchehri Soheil , Hardouin Guillaume , Kaye David , Potter Jason 
Published: September 2014

Pipe-In-Pipe (PIP) systems are increasingly used in subsea oil and gas production where a low Overall Heat Transfer Coefficient (OHTC) is required. A PIP system is primarily composed of an insulated inner pipe which carries the production fluid and an outer pipe that protects the insulation material from the seawater environment. This provides a dry environment within the annulus and therefore allows the use of high quality dry insulation system. In addition, from a safety point of view, it provides additional structural integrity and a protective barrier which safeguards the pipeline from loss of containment to the environment.
Genesis has designed a number of PIP systems in accordance with the recognized subsea pipeline design codes including DNV-OS-F101 [1]. In section 13 F100 of the 2013 revision, a short section has been included in which PIP systems are discussed and overall design requirements for such systems are provided. It has also been stated that the inner and outer pipes need to have the same Safety Class (SC) unless it can be documented otherwise.
This paper looks at the selection of appropriate SC for the outer pipe in a design of PIP systems based on an assessment of different limit states, associated failure modes and consequences. Firstly, the fundamentals of selecting an acceptable SC for a PIP system are discussed. Then, different limit states and most probable failure modes that might occur under operational conditions are examined (in accordance with the requirements of [1]) and conclusions are presented and discussed. It is concluded that the SC of the outer pipe of a PIP system may be lower than that of the inner pipe, depending on the failure mode and approach adopted by the designer.
Green Water Phenomena on a Twin-Hull FLNG Concept
Authors: van ‘t Veer Riaan , Vlasveld Ebert 
Published: September 2014

This paper investigates — based on model tests and potential flow calculations — several phenomena associated with the green water problem in severe sea states. The topics investigated are: the wave characteristics of the severe and steep sea states, the behavior of the vessel in these waves, the relative motions at the bow and the height of water on deck.
The green water problem is of interest since many floaters used for the oil and gas production by the offshore industry are permanently moored for typically 20 years or more, and they will experience severe storm conditions with large wave heights.
The investigations concern an unusual vessel type: SBM’s innovative midscale Twin-Hull FLNG concept [1]. The floater concept is to join two (standard) LNG carriers together to obtain sufficient storage volume and process deck space. The concept is under development and one aspect, from operability point of view, is the probability for green water. For this purpose a first model test campaign has been carried out.
The Twin-Hull FLNG concept has been tested in extreme sea states which are typical for offshore Brazil and East-Africa.
Linear potential flow calculations were applied to predict the freeboard exceedance based on relative motion amplitude operators. The correlation to the measured data is discussed.
Although the research is dedicated to the Twin-Hull FLNG vessel, the observed phenomena are considered applicable to any stationary vessel in general.