bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nanoemulsion with Controlled Rheology under Different Temperature for Effective Removal of Oil-based Drilling Fluid in Offshore Drilling
Authors: Meng Renzhou , Wang Chengwen , Dong Xiliang , Xiong Chao 
Published: October 2021

Abstract
Oil-based drilling fluid (OBDF) is an important means for offshore drilling, but it would affect the cementing quality. Nanoemulsions shows potential for OBDF removal, but how to prepare nanoemulsion meeting the engineering requirement is lack of good understanding. Moreover, nanoemulsions usually behave badly under low/high temperature, which would restrict the application. Revealing removal mechanisms of nanoemulsion and improving nanoemulsion stability at different temperature are of great significance.
The nanoemulsion could rapidly spread on the wellbore surfaces, cause the adhering OBDF to curl into little droplets, and solubilize the removed OBDF. The removal efficiency can reach more than 98%. Low temperature and higher concentration of dispersed phase both increased the viscosity of nanoemulsions stabilized by surfactants. PEGs can induce the bridging of emulsion droplets at low temperature, leading to significant increase of nanoemulsions viscoelasticity at low temperature (around 5°C). To control the rheological properties of nanoemulsions, a hydrophobic association polymer, HAAP, was proposed. Nanoemulsions containing HAAP does not gel at low temperature (&lt; 15°C). And the viscoelasticity of nanoemulsions increased slightly when the temperature is higher than 70°C because of the thermoassociating behavior of polymer, which can ensure the stability of the nanoemulsions at high temperature.
This paper is helpful to establish a generic route for preparing nanoemulsions with controlled rheological properties under different temperature, which is benefit for their applications in offshore.
Prediction of Pressure Drops in Liquid-Liquid Two-Phase Flow Across Circular Channels
Authors: Khan Zurwa , Tafreshi Reza , Wahid MD Ferdous , Retnanto Albertus 
Published: October 2021

Abstract
Mechanistic models are necessary for understanding and predicting the behavior of liquid-liquid flow for multiple pipe dimensions, mixture properties, and flow patterns. In this paper, a mechanistic model is proposed to calculate pressure drop across circular channels for liquid-liquid two-phase flow. The developed model considers several key aspects of liquid-liquid flow, such as mixed and wavy liquid-liquid interfaces and dispersion within each liquid’s layers. Unique identifiers, such as height, turbulence, and dispersion, are calculated for each phase, using an augmented separated flow model and nonlinear optimization. Comparison of the proposed model with experimental data, comprising of multiple inclination angles and flow patterns, shows accurate predictions for a variety of liquid-liquid flow patterns, including double- and triple-layered flow.
Clustering Applied to Large Sets of Environmental Conditions for Selecting Typical Scenarios for Ship Maneuvering Real-Time Simulations
Authors: Moreno Felipe M. , Tannuri Eduardo A. 
Published: October 2021

Abstract
The methodology described in this paper is used to reduce a large set of combined wind, waves, and currents to a smaller set that still represents well enough the desired site for ship maneuvering simulations. This is achieved by running fast-time simulations for the entire set of environmental conditions and recording the vessel’s drifting time-series while it is controlled by an automatic-pilot based on a line-of-sight algorithm. The cases are then grouped considering how similar the vessel’s drifting time-series are, and one environmental condition is selected to represent each group found by the cluster analysis. The measurement of dissimilarity between the time-series is made by application of Dynamic Time Warping and the Cluster Analysis is made by the combination of Partitioning Around Medoids algorithm and the Silhouette Method. Validation is made by maneuvering simulations made with a Second Deck Officer.
Use of DNVGL-RP-C203 for Determining the Fatigue Capacity of Connectors
Authors: Muff Anthony , Wormsen Anders , Hørte Torfinn , Fjeldstad Arne , Osen Per , Kirkemo Finn , Macdonald Kenneth A. , Reinås Lorents 
Published: October 2021

Abstract
Guidance for determining a S-N based fatigue capacity (safe life design) for preloaded connectors is included in Section 5.4 of the 2019 edition of DNVGL-RP-C203 (C203-2019). This section includes guidance on the finite element model representation, finite element based fatigue analysis and determination of the connector design fatigue capacity by use of one of the following methods: Method 1 by FEA based fatigue analysis, Method 2 by FEA based fatigue analysis and experimental testing and Method 3 by full-scale connector fatigue testing. The FEA based fatigue analysis makes use of Appendix D.2 in C203-2019 (“S-N curves for high strength steel applications for subsea”). Practical use of Section 5.4 is illustrated with a case study of a fatigue tested wellhead profile connector segment test. Further developments of Section 5.4 of C203-2019 are proposed. This included acceptance criteria for use of a segment test to validate the FEA based fatigue analysis of a full-scale preloaded connector.
Limit Load Capacity of Thick-Walled Pipe Loaded by Internal Pressure and Bending
Authors: Selker Ruud , Brugmans Joost , Liu Ping , Sicilia Carlos 
Published: October 2021

Abstract
Internally pressurised pipe behaves differently than externally pressurised pipe. DNVGL-ST-F101 [4], a prevailing standard for the design of submarine pipelines, provides limit-state equations for combined loading that are valid only if the diameter-to-wall-thickness ratio (D/t) is between 15 and 45. A recent study has shown that the results are increasingly conservative for lower values of this ratio if the nett pressure is acting on the pipe’s outside [8], especially if it is below 20.
In this paper, the applicability of the limit-state equations for thick-walled pipe with D/t less than 15 and loaded by a nett internal pressure has been investigated. The first step was a fundamental review of the formulations. Next, the predicted capacities were compared with those estimated using a finite-element (FE) model. The results greatly coincided, which indicates that the conservatism underlying the formulations does not depend on D/t. Hence they can be used for design against local buckling under internal overpressure, too, when the ratio is below 15.
Comparison Between Shrinkage Strain and FEM Thermo-Mechanical Method for Estimation of Welding Induced Residual Stresses
Authors: Bhardwaj Sachin , Ratnayake R. M. Chandima 
Published: October 2021

Abstract
Residual stress estimation in structural integrity procedures plays an important role during the fitness-for-service (FFS) assessment of girth welds. Various FFS codes and standards, such as API 579 and BS 7910, recommend predetermined residual stress profiles based on finite element modeling (FEM) coupled with experimental results. Nonlinearity associated with non-uniform temperature gradients’ distribution during welding can develop residual stress up to the yield strength of the material, in weld shrinkage and plastic zones. Plastic zone size, shape, and locations are critically important in reducing or controlling final distortions, decreasing the residual stress according to length scale, and defining the optimum sequence of the welding process. However, in practice, estimation of finally developed residual stresses is used in structural integrity procedures for determining the FFS of welded joints. Various FEM models employed in its assessment require large computational time in solving the complex thermo-mechanical phenomenon involved in the welding process. Shrinkage strain models have been found to be fast and effective in determining final residual stresses, once the size, location and shape of the plastic zone can be predetermined. This manuscript demonstrates a comparison between the shrinkage strain method and the moving heat source method, based on transient temperature development as a function of time. The results (or findings) reveal a high compromise between FEM thermo mechanical model and shrinkage strain method in determining final residual stresses with later consuming less computational time. The findings provide significantly important feedback to welded joints’ structural integrity assurance practitioners.
What You May Not Know About Pipe Bends
Authors: Selker Ruud , Liu Ping , Sicilia Carlos 
Published: October 2021

Abstract
Pipe bends are peculiar structures. Although the mechanisms that determine their behaviour are not that different from those of initially straight pipe, their relative contribution can be. This is amplified by shorter bend radii and thinner walls. Typical bends used in an offshore environment will have a radius of three to ten times their cross-section diameter and will behave differently than straight pipe of comparable dimensions. This paper aims to identify and quantify the key mechanisms that drive the behaviour of pipe bends in a deep-water environment. Their behaviour has been studied at global and local scales. The behaviour of bends seems not fully understood amongst academia and in the industry. This paper endeavours to demystify some of those peculiar behaviours, for example, why pipe bends tend to straighten during a mill pressure test.
A Model for Ice Heterogeneity Affecting Bending Failure Against An Inclined Structure
Authors: Simakina Aleksandra , Zvyagin Petr , Drepin Mikhail 
Published: October 2021

Abstract
Experiments with model ice are usually carried out for preliminary assessment of ice qualities of designed offshore structures. Despite the fact that properties of model ice across artificial floe are constant, sometimes various experimental results can be explained not only by measurement errors.
The paper describes various positions of breaking points in a number of model experiments with an ice beam flexural failure. To explain the observed effect, the article suggests the hypothesis on heterogeneity of elastic modulus of an ice floe. The article considers a problem of possible influence of the area of heterogeneity on the position of an ice beam breaking point. Thus, the models of a cantilever beam and a plane lying on an elastic foundation with inconstant Young’s modulus are suggested. These models in form of their approximations by finite differences are applied for making numerical simulations in order to investigate the problem.
With the numerically obtained solutions of a cantilever beam and a plane on an elastic foundation with employed inhomogeneity of elastic modulus, the study observed noticeable change in the position of the breaking point when such inhomogeneity occurred close to the contact area.
A Probabilistic High-Pressure Zone Model of Dynamic Ice Structure Interactions and Associated Ice-Induced Vibrations
Authors: Hossain Ridwan , Taylor Rocky , Moro Lorenzo 
Published: October 2021

Abstract
During ice-structure interactions that are dominated by ice compressive failure, the majority of the ice loads are transmitted through localized contact regions known as high-pressure zones (hpzs). This paper presents a probabilistic modelling framework for dynamic ice-structure interaction based on the mechanics of hpzs. Individual hpzs are modelled as a nonlinear spring-damper system where the stiffness is modelled as a function of nominal strain, with the degree of softening depending on the average strain-rate. Both spalling and crushing failure mechanisms were assessed in the context of periodical sinusoidal response. For spall dominated failure, the model structure showed presence of frequency lock-in in the speed range of 100–125mm/s, beyond which the failure was found to be random in nature with lower amplitude of structural response. The amplitude was also found to be significantly influenced by structural parameters with structural damping having the highest contribution. For pure crushing, an estimated equilibrium layer thickness based on theoretical calculations also showed presence of frequency lock-in. The work highlights the importance of understanding the interplay between these mechanisms, as well as the role of ice conditions and structural parameters on the processes that dominate an interaction.
Semantic Search in Offshore Engineering With Linguistics And Neural Processing Pipelines
Authors: Pol Gonçalves Flavio Jaime , de Oliveira Carmo Vinicius Cleves , Toquetti de Melo Vinicius , Cunha Rodrigo da Silva , Santos Ismael H. F. , Barreira Rodrigo Augusto , Cugnasca Carlos Eduardo , Cozman Fabio Gagliardi , Gomi Edson Satoshi 
Published: October 2021

Abstract
This paper presents a computing pipeline architecture for semantic search in the domain of Offshore Engineering. The proposed system combines modules such as document retriever, passage retriever, and answer extractor to produce textual responses to queries in natural language such as: “What FPSO motion is mostly affected by viscous damping?” Such responses are often needed in Offshore Engineering activities, and linguistic techniques such as those based on inverted indexes with a syntactic focus tend to perform poorly. Instead, this research explores semantic techniques that take into account the meaning of words in the domain of Offshore Engineering. This paper describes a Linguistic QA pipeline architecture built that provides a way to retrieve answers instantly from a collection of 13,000 unstructured technical documents about Offshore Engineering, reports the achieved results and future work. This paper also presents additional modules under construction that exploit Neural Networks and ontologies approaches for semantic search in the domain of Offshore Engineering.
Performance Evaluation of Hybrid Thermal-Solvent Injection in a Post-CHOPS Reservoir With Consideration of Wormhole Network
Authors: Zhao Min , Yang Shikai , Yang Daoyong 
Published: October 2021

Abstract
In this paper, techniques have been developed to evaluate performance of thermal, solvents, and hybrid thermal-solvent processes in a post-CHOPS reservoir with consideration of wormhole network. With the experimentally determined properties of injected gases and reservoir fluids, history matching is accomplished for the reservoir geological model conditioned to the fluid and sand production profiles together with pressure. Meanwhile, the wormhole network is characterized with the newly developed pressure-gradient-based (PGB) sand failure criterion. Once the history matching is completed, the calibrated reservoir geological model is then employed to evaluate performance of thermal, solvents, and hybrid thermal-solvent processes under various conditions. It is found that huff-n-puff processes have a very good performance on enhancing oil recovery when wormhole network is fully generated and propagated. Among all solvent-based methods, pure CO2 huff-n-puff process shows a better performance than flue gas, while the addition of alkane solvents leads to a higher oil recovery compared with CO2 only method. Since the addition of C3H8 and n-C4H10 will significantly decrease the heavy oil viscosity and enhance the swelling factor, all hybrid thermal-solvent injection achieves high oil recovery by taking the advantage of both hot steam and solvents injection.
Concept Study for the Floater Type Selection on Floating Offshore Wind Turbines
Authors: Chujo Toshiki , Haneda Ken 
Published: October 2021

Abstract
The FOWTs (Floating Offshore Wind Turbines) projects are spreading, especially in Europe. Some of FOWTs are doing commercial activities, on the other hand, many new concepts of FOWTs are still published in the world. This may mean that there is room for the reduction of the construction cost of the floater, therefore the development of more reasonable design of the floater would give rise to big business opportunities. These new concept of FOWTs are thought to be optimized regarding the safety and economic efficiency, but there are a few studies for the comparison in the safety, economic efficiency, and parameters which effect to them between different types of floater concepts. Therefore, authors carried out the parametric study in terms of the motion in waves and wind and construction cost for the semi-submersible type and the spar type. In this study, 2, 5, 10, 15MW wind turbines are assumed to be installed on the floater, and dimensions of the floater and an inclination angle because of the maximum thrust force are set as constraint conditions. The construction cost is estimated as a product of material weight and unit cost of material. Authors found the solution regarding the relationship between the construction cost and the performance of the FOWTs through this study. the distance between the columns and the lower pontoon breadth were effective parameters to ensure he performance in waves and to reduce the construction cost of semi-submersible floater.
Optimization of Resistance Performance for Inland Twin-Skeg Ship Based on CFD and Surrogate Modeling
Authors: Yan Helei , Feng Baiwei , Zheng Qiang , Li Heng 
Published: October 2021

Abstract
With the increasingly serious energy problems in the world and the introduction of Energy Efficiency Design Index (EEDI) by International Maritime Organization (IMO), the application of energy conservation and emission reduction methods in ships has been paid more and more attention. With the rapid development of computational fluid dynamics (CFD), ship hull form optimization based on CFD has become a hot topic, Inland twin-skeg ship has a relatively complicated hull form, and it has strong theoretical significance and engineering practical value to carry out hull form optimization research on this type of ship. Based on the multidisciplinary comprehensive optimization platform for ship hydrodynamic performance (SHIPMDO-WUT) self-developed by Wuhan University of Technology research institute of multidisciplinary design optimization of ship performance, this paper using the hull surface deformation method based on the radial basis function interpolation to change the hull form and skeg shape of a 3000t inland twin-skeg oil tanker with invisible bulbous bow. And the high-precision CFD calculation software SHIPFLOW was used to predict the resistance of this ship. Finally, combined with CFD surrogate model and optimization algorithm, the ship with excellent resistance performance is obtained and ensuring the ship displacement and the longitudinal position of the buoyancy center are within the range of certain constraints. At last, the optimization results were verified numerically.
Full-Scale In-Situ Four-Point Beam Bending Field Tests on Sea Ice
Authors: Taylor Rocky , Turnbull Ian , Bailey-Dudley Eleanor , Pritchett Rob 
Published: October 2021

Abstract
The flexural strength of ice is not a basic material property, but rather is an estimate of the maximum stress in the outermost fiber of an ice specimen when it fails in bending. Such conditions correspond to a number of important engineering applications, such as interactions between ice and a sloping structure or between ice and ships. Ice flexural strength is therefore highly important for calculating ice pressures and forces of interest for engineering design. While there has been considerable discussion in the literature regarding scale effects related to ice crushing against a vertical structure, scale effects in relation to bending failure have received much less attention. To this end, more flexural strength data for large, full-thickness sea ice beams are needed. To address these data gaps, a field data collection program was carried out in Pistolet Bay, Newfoundland over two field seasons (2017–2018). During this program, large sea ice beams were tested in-situ using a custom four-point bending apparatus, which was comprised of several main subsystems (e.g., the ram loading system, the platen, the ubrackets, and the hydraulic system). The sea ice beams were completely cut free from the ice cover and loaded at four points, such that the center load is parallel, but opposed to, the loads at the ends of the beam. All tests were done in-situ so that no brine drainage took place and the temperature gradient remained consistent. Tests were carried out for several combinations of beam geometry, which were scaled relative to the ice thickness. In addition to flexural strength, during the Pistolet Bay field program, the physical properties of the ice were measured (temperature, salinity, density). In this paper, a description of the field apparatus, test program and results from the full-thickness in-situ four-point beam bending tests are presented, along with a discussion of practical implications and future work.
Pipe Joint Management for Risers and Pipelines
Authors: Mansour Ghiath (Guy) 
Published: October 2021

Abstract
Minimizing the stress concentration factor (SCF) in pipe joint welding subjected to fatigue is a major concern. Machining the joint ends is one way to achieve this. However, this adds cost, time, risk of potential crack starters, and loss of wall thickness which is detrimental for fatigue, strength, and engineering criticality assessment (ECA) in particular. Pipe joint sorting (certain joints in sequence) and end matching (rotating the pipe joints for best fit) are other ways. However, this adds time, costly logistics, risk of errors, and does not guarantee the minimum possible SCF is achieved. In a typical project, more pipe joints are procured than required in order to mitigate contingencies. For pipelines, this overage is typically a percentage of the required number of joints or pipeline length. For risers, typically double the required number of joints is procured where half of the joints is sent offshore for installation and the remaining half is kept onshore for a spare riser. Then, it becomes very important to send for installation the best pipe joints that produce the best (lowest) SCFs out of the entire batch of pipe joints. This requires calculating the SCF for every potential match of any random joints to be welded together, and then choosing the best joints. Performing such calculations by spreadsheet is not feasible considering the tremendous number of required iterations and calculations. A pipe joint management software development is presented herein which accomplishes this task and examples provided to illustrate the benefits.
Note: Selecting pipe joints with the best end measurements, whether ID, OD, OOR, or thickness does not guarantee that the minimum possible SCFs will be achieved since the SCF is a function of all those measurements.